Methods for producing aldehyde compounds and dihydroisoxazole compounds

Abstract

The present invention addresses the problem of providing an industrially preferable method for producing an aldehyde represented by formula (3) or (4): (3) (4).　The present invention produces a compound of formula (3) or compound of formula (4) by causing a corresponding compound of formula (1) or compound of formula (2) to undergo, in the presence of a metal catalyst, nitric acid, oxygen, and a nitroxyl radical compound, reaction represented by the following reaction formulae.　The present invention further addresses the problem of providing an industrially preferable method for producing a dihydroisoxazole represented by formula (7): (7). The obtained compound of formula (3) or compound of formula (4) is subjected to an oximation step and a cyclization step to produce the compound of formula (7).

Description

[Technical Field] 【0001】 The present invention relates to formula (7): 【0002】 [ka] 【0003】 (In the formula, R 1 and R 2 This relates to a method for producing the compound, namely dihydroisoxazole, as described below. In this specification, dihydroisoxazole is also referred to as isoxazoline. Furthermore, the present invention relates to formula (3) or formula (4): 【0004】 [ka] 【0005】 (In the formula, R 1 , R 2 and R 3 This relates to a method for producing compounds of aldehydes, as described below. [Background technology] 【0006】 Compounds of formula (3) or formula (4) are useful as intermediates in the manufacture of pharmaceuticals and agrochemicals. Patent document 1 (WO2002 / 062770A1) discloses useful herbicides, and compounds of formula (3) or formula (4) can be used as intermediates in said herbicides. Among said herbicides, pyroxasulfone is well known as an herbicide with excellent herbicidal activity. Patent document 2 (WO2020 / 251006A1) discloses a method for producing dihydroisoxazole, and dihydroisoxazole can also be used as an intermediate in herbicides such as pyroxasulfone. 【0007】 Scheme of Patent Document 2 (WO2020 / 251006A1): 【0008】 [ka] 【0009】 In the figure above, the method described in Patent Document 2 (WO2020 / 251006A1) involves reacting alcohol with sodium hypochlorite, followed by oximation and cyclization. 【0010】 Patent document 5 (WO2019 / 117255A1) also discloses a method for producing intermediates of herbicides such as pyroxasulfone. 【0011】 Scheme of Patent Document 5 (WO2019 / 117255A1): 【0012】 [ka] 【0013】 As shown in the figure above, in the method described in Patent Document 5 (WO2019 / 117255A1), an oxime reaction is performed first, followed by a cyclization reaction. 【0014】 Patent document 6 (WO2019 / 208643A1) also discloses a method for producing intermediates of herbicides such as pyroxasulfone. The method is shown in the figure below. 【0015】 Scheme of Patent Document 6 (WO2019 / 208643A1): 【0016】 [ka] 【0017】 However, there was a demand for a more efficient method of producing the compound of formula (7). For example, the method described in Patent Document 2 (WO2020 / 251006A1) was deemed to need improvement in the method of producing the intermediate aldehyde compound. The methods described in Patent Documents 5 (WO2019 / 117255A1) and 6 (WO2019 / 208643A1) were also deemed to need improvement in the method of producing the raw material aldehyde compound. 【0018】 For example, Patent Document 3 (WO2005 / 082825A1) and Patent Document 4 (CN101709026A) disclose an oxidation method using oxygen as a method for producing aldehyde compounds. When the alcohol compound of formula (1) was used as a raw material and reacted using the reaction conditions of the examples in Patent Document 3 (WO2005 / 082825A1) and Patent Document 4 (CN101709026A), the aldehyde compound of formula (3) was produced in a low yield (Comparative Examples 10-12). 【0019】 Given the industrial importance of the compound of formula (3) described above, there was a need for a more industrially favorable method for producing the compound of formula (3) than the conventional method. [Prior art documents] [Patent Documents] 【0020】 [Patent Document 1] International Publication No. 2002 / 062770 [Patent Document 2] International Publication No. 2020 / 251006 [Patent Document 3] International Publication No. 2005 / 082825 [Patent Document 4] Chinese Patent Application Publication No. 101709026 Specification [Patent Document 5] International Publication No. 2019 / 117255 [Patent Document 6] International Publication No. 2019 / 208643 [Overview of the project] [Problems that the invention aims to solve] 【0021】 The object of the present invention is to provide an efficient and industrially preferable method for producing the compound of formula (7) described above. A further object of the present invention is to provide an industrially preferred method for producing the compound of formula (3) or formula (4). Specifically, the object is to provide a method for producing the compound of formula (3) or formula (4) (aldehyde compound) from the compound of formula (1) or formula (2) (alcohol compound) by simple operations, wherein the proportion of carboxylic acid derivatives and ester derivatives produced as by-products is sufficiently low, the yield is excellent, and the method is advantageous for industrial production. [Means for solving the problem] 【0022】 In light of the above circumstances, the inventors diligently researched methods for producing compounds of formula (3) or formula (4). As a result, it was unexpectedly discovered that the above problems could be solved by providing the following methods for producing compounds of formula (3) or formula (4). Based on this finding, the inventors completed the present invention. 【0023】 In other words, in one embodiment, the present invention is as follows: 【0024】 [I-1] A method for producing the compound of formula (7), comprising the following steps; Step (i) Reacting the compound of formula (1) or the compound of formula (2) in the presence of a metal catalyst, nitric acid, oxygen, and a nitroxyl radical compound to obtain the corresponding compound of formula (3) or the compound of formula (4): 【0025】 [ka] (In the formula, R 1 and R 2 Each of these is independently a substituted (C1-C6) alkyl, and R 3is a hydrogen atom; optionally substituted (C1-C6) alkyl; optionally substituted (C3-C6) cycloalkyl; optionally substituted (C6-C10) aryl; or optionally substituted (C6-C10) aryl(C1-C4) alkyl.) Step (ii) Reacting the compound of formula (3) or the compound of formula (4) with an oxime-forming agent to obtain the corresponding compound of formula (5) or the compound of formula (6) respectively: 【0026】 【Chemical formula】 (wherein, R 1 , R 2 and R 3 are as defined above.) Step (iii) Reacting the compound of formula (5) or the compound of formula (6) in the presence of an acid catalyst or in the presence of an acid catalyst and a base catalyst to obtain the compound of formula (7): 【0027】 【Chemical formula】 (wherein, R 1 , R 2 and R 3 are as defined above.). 【0028】 〔I-2〕 A method for producing the compound of formula (7), comprising the following steps; Step (i-a) Reacting the compound of formula (1) in the presence of a metal catalyst, nitric acid, oxygen and a nitroxyl radical compound to obtain the compound of formula (3): 【0029】 [ 【Chemical formula】 (wherein, R 1 and R 2 are each independently optionally substituted (C1-C6) alkyl, and R 3This is a hydrogen atom; an optionally substituted (C1-C6) alkyl; an optionally substituted (C3-C6) cycloalkyl; an optionally substituted (C6-C10) aryl; or an optionally substituted (C6-C10) aryl(C1-C4) alkyl. Step (ii-a): The compound of formula (3) is reacted with an oximating agent to obtain the compound of formula (5): 【0030】 [ka] (In the formula, R 1 , R 2 and R 3 (This is as defined above.) Step (iii-a) React the compound of formula (5) in the presence of an acid catalyst, or in the presence of both an acid catalyst and a base catalyst, to obtain the compound of formula (7): 【0031】 [ka] (In the formula, R 1 , R 2 and R 3 This is as defined above. 【0032】 [I-3] A method for producing the compound of formula (7), comprising the following steps; Step (ib) The compound of formula (2) is reacted in the presence of a metal catalyst, nitric acid, oxygen, and a nitroxyl radical compound to obtain the compound of formula (4): 【0033】 [ka] (In the formula, R 1 and R 2 Each of these is independently a substituted (C1-C6) alkyl, and R 3This is a hydrogen atom; an optionally substituted (C1-C6) alkyl; an optionally substituted (C3-C6) cycloalkyl; an optionally substituted (C6-C10) aryl; or an optionally substituted (C6-C10) aryl(C1-C4) alkyl. Step (ii-b): The compound of formula (4) is reacted with an oximating agent to obtain the compound of formula (6): 【0034】 [ka] (In the formula, R 1 , R 2 and R 3 (This is as defined above.) Step (iii-b) React the compound of formula (6) in the presence of an acid catalyst, or in the presence of both an acid catalyst and a base catalyst, to obtain the compound of formula (7): 【0035】 [ka] (In the formula, R 1 , R 2 and R 3 This is as defined above. 【0036】 [I-4] A method for producing a compound of formula (3) or formula (4), comprising the following steps; Step (i) Reacting the compound of formula (1) or the compound of formula (2) in the presence of a metal catalyst, nitric acid, oxygen, and a nitroxyl radical compound to obtain the corresponding compound of formula (3) or the compound of formula (4): 【0037】 [ka] (In the formula, R 1 and R 2 Each of these is independently a substituted (C1-C6) alkyl, and R 3This is a hydrogen atom; optionally substituted (C1-C6) alkyl; optionally substituted (C3-C6) cycloalkyl; optionally substituted (C6-C10) aryl; or optionally substituted (C6-C10) aryl(C1-C4) alkyl. 【0038】 [I-5] A method for producing the compound of formula (3), comprising the following steps; Step (ia) React the compound of formula (1) in the presence of a metal catalyst, nitric acid, oxygen, and a nitroxyl radical compound to obtain the compound of formula (3): 【0039】 [ka] (In the formula, R 1 and R 2 Each of these is independently a substituted (C1-C6) alkyl, and R 3 This is a hydrogen atom; optionally substituted (C1-C6) alkyl; optionally substituted (C3-C6) cycloalkyl; optionally substituted (C6-C10) aryl; or optionally substituted (C6-C10) aryl(C1-C4) alkyl. 【0040】 [I-6] A method for producing the compound of formula (4), comprising the following steps; Step (ib) The compound of formula (2) is reacted in the presence of a metal catalyst, nitric acid, oxygen, and a nitroxyl radical compound to obtain the compound of formula (4): 【0041】 [ka] (In the formula, R 1 and R 2 Each of these is independently a substituted (C1-C6) alkyl, and R 3This is a hydrogen atom; optionally substituted (C1-C6) alkyl; optionally substituted (C3-C6) cycloalkyl; optionally substituted (C6-C10) aryl; or optionally substituted (C6-C10) aryl(C1-C4) alkyl. 【0042】 [I-7] A manufacturing method described in any one of items [I-1] to [I-6], wherein the metal catalyst in step (i), step (ia), or step (ib) is an iron catalyst or a copper catalyst, excluding methods that do not fall under this category. 【0043】 [I-8] A manufacturing method described in any one of items [I-1] to [I-6], wherein the metal catalyst in step (i), step (ia), or step (ib) is iron(III) nitrate, or a catalyst containing iron(III) chloride, iron(III) bromide, or iron(III) iodide and nitric acid, excluding methods that do not fall under these categories. 【0044】 [I-9] A manufacturing method described in any one of items [I-1] to [I-6], wherein the metal catalyst in step (i), step (ia), or step (ib) is iron(III) nitrate, or a catalyst containing iron(III) chloride or iron(III) bromide and nitric acid, excluding methods that do not fall under these categories. 【0045】 [I-10] A manufacturing method described in any one of items [I-1] to [I-6], wherein the metal catalyst in step (i), step (ia), or step (ib) is a catalyst containing iron(III) chloride or iron(III) bromide and nitric acid, excluding methods that do not fall under this category. 【0046】 [I-11] A manufacturing method described in any one of items [I-1] to [I-6], wherein the metal catalyst in step (i), step (ia), or step (ib) is a catalyst containing iron(III) chloride and nitric acid, excluding methods that do not fall under this category. 【0047】 [I-12] A manufacturing method described in any one of items [I-1] to [I-6], wherein the metal catalyst in step (i), step (ia), or step (ib) is copper(II) nitrate, or a catalyst containing copper(II) chloride, copper(II) bromide, or copper(II) iodide and nitric acid, excluding methods that do not fall under these categories. 【0048】 [I-13] A manufacturing method described in any one of items [I-1] to [I-6], wherein the metal catalyst in step (i), step (ia), or step (ib) is a catalyst containing copper(II) chloride or copper(II) bromide and nitric acid, excluding methods that do not fall under this category. 【0049】 [I-14] A manufacturing method described in any one of items [I-1] to [I-6], wherein the metal catalyst in step (i), step (ia), or step (ib) is iron(III) chloride, iron(III) bromide, or iron(III) iodide, excluding methods that do not fall under this category. 【0050】 [I-15] A manufacturing method described in any one of items [I-1] to [I-6], wherein the metal catalyst in step (i), step (ia), or step (ib) is iron(III) chloride or iron(III) bromide, excluding methods that do not fall under this category. 【0051】 [I-16] A manufacturing method described in any one of items [I-1] to [I-6], wherein the metal catalyst in step (i), step (ia), or step (ib) is iron(III) chloride, excluding methods that do not fall under this category. 【0052】 [I-17] A manufacturing method described in any one of items [I-1] to [I-16], wherein the amount of nitric acid used in step (i), step (ia), or step (ib) is 0.01 moles to 1 mole per mole of the compound of formula (1) or the compound of formula (2), excluding methods that do not fall under this category. 【0053】 [I-18] A manufacturing method described in any one of items [I-1] to [I-16], wherein the amount of nitric acid used in step (i), step (ia), or step (ib) is 0.02 moles to 0.9 moles per mole of the compound of formula (1) or the compound of formula (2), excluding methods that do not fall under this category. 【0054】 [I-19] A manufacturing method described in any one of items [I-1] to [I-16], wherein the amount of nitric acid used in step (i), step (ia), or step (ib) is 0.01 moles to 0.1 moles per mole of the compound of formula (1) or the compound of formula (2), excluding methods that do not fall under this category. 【0055】 [I-20] A manufacturing method described in any one of items [I-1] to [I-16], wherein the amount of nitric acid used in step (i), step (ia), or step (ib) is 0.02 moles to 0.05 moles per mole of the compound of formula (1) or the compound of formula (2), excluding methods that do not fall under this category. 【0056】 [I-21] A manufacturing method described in any one of items [I-1] to [I-16], wherein the amount of nitric acid used in step (i), step (ia), or step (ib) is 0.5 moles to 1 mole per mole of the compound of formula (1) or the compound of formula (2), excluding methods that do not fall under this category. 【0057】 [I-22] A manufacturing method described in any one of items [I-1] to [I-16], wherein the amount of nitric acid used in step (i), step (ia), or step (ib) is 0.5 moles to 0.9 moles per mole of the compound of formula (1) or the compound of formula (2), excluding methods that do not fall under this category. 【0058】 [I-23] A manufacturing method described in any one of items [I-1] to [I-16], wherein the amount of nitric acid used in step (i), step (ia), or step (ib) is 0.5 moles to 0.8 moles per mole of the compound of formula (1) or the compound of formula (2), excluding methods that do not fall under this category. 【0059】 [I-24] A manufacturing method described in any one of items [I-1] to [I-23], wherein the reaction of step (i), step (ia), or step (ib) is carried out in the presence of an acid, excluding methods that do not fall under this category. 【0060】 [I-25] A manufacturing method described in any one of items [I-1] to [I-24], wherein the acid in step (i), step (ia), or step (ib) is a carboxylic acid, excluding methods that do not fall under this category. 【0061】 [I-26] A manufacturing method described in any one of items [I-1] to [I-24], wherein the acid in step (i), step (ia), or step (ib) is acetic acid, propionic acid, or benzoic acid, excluding methods that do not fall under these categories. 【0062】 [I-27] A manufacturing method described in any one of items [I-1] to [I-24], wherein the acid in step (i), step (ia), or step (ib) is acetic acid, excluding methods that do not fall under this category. 【0063】 [I-28] A manufacturing method described in any one of items [I-1] to [I-27], wherein the reaction of step (i), step (ia), or step (ib) is carried out in the presence of a base, excluding methods that do not fall under this category. 【0064】 [I-29] A manufacturing method described in any one of items [I-1] to [I-28], wherein the base in step (i), step (ia), or step (ib) is an aromatic heterocycle having a nitrogen atom, excluding methods that do not fall under this category. 【0065】 [I-30] A manufacturing method described in any one of items [I-1] to [I-28], wherein the base of step (i), step (ia), or step (ib) is N-methylimidazole, 2,2'-bipyridyl, N-methylpyrazole, pyridine, or N,N-dimethylaminopyridine, excluding methods that do not fall under these categories. 【0066】 [I-31] A manufacturing method described in any one of items [I-1] to [I-28], wherein the base of step (i), step (ia), or step (ib) is N-methylimidazole or 2,2'-bipyridyl, excluding methods that do not fall under this category. 【0067】 [I-32] A manufacturing method described in any one of items [I-1] to [I-31], wherein the amount of acid used in step (i), step (ia), or step (ib) is 0.5 to 3 moles per mole of compound of formula (1) or compound of formula (2), excluding methods that do not fall under this category. 【0068】 [I-33] A manufacturing method described in any one of items [I-1] to [I-31], wherein the amount of acid used in step (i), step (ia), or step (ib) is 1 to 2 moles per mole of compound of formula (1) or compound of formula (2), excluding methods that do not fall under this category. 【0069】 [I-34] A manufacturing method described in any one of items [I-1] to [I-33], wherein the amount of base used in step (i), step (ia), or step (ib) is 0.001 to 0.3 moles per mole of compound of formula (1) or compound of formula (2), excluding methods that do not fall under this category. 【0070】 [I-35] A manufacturing method described in any one of items [I-1] to [I-33], wherein the amount of base used in step (i), step (ia), or step (ib) is 0.01 to 0.1 moles per mole of compound of formula (1) or compound of formula (2), excluding methods that do not fall under this category. 【0071】 [I-36] A manufacturing method described in any one of items [I-1] to [I-35], wherein the amount of metal catalyst used in step (i), step (ia), or step (ib) is 0.001 to 0.3 moles per mole of the compound of formula (1) or the compound of formula (2), excluding methods that do not fall under this category. 【0072】 [I-37] A manufacturing method described in any one of items [I-1] to [I-35], wherein the amount of metal catalyst used in step (i), step (ia), or step (ib) is 0.01 to 0.1 moles per mole of the compound of formula (1) or the compound of formula (2), excluding methods that do not fall under this category. 【0073】 [I-38] A manufacturing method described in any one of items [I-1] to [I-37], wherein the nitroxyl radical compound in step (i), step (ia), or step (ib) is 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl, excluding methods that do not fall under this category. 【0074】 [I-39] A manufacturing method described in any one of items [I-1] to [I-38], wherein the amount of nitroxyl radical compound used in step (i), step (ia), or step (ib) is 0.001 to 0.3 moles per mole of the compound of formula (1) or the compound of formula (2), excluding methods that do not apply. 【0075】 [I-40] A manufacturing method described in any one of items [I-1] to [I-38], wherein the amount of nitroxyl radical compound used in step (i), step (ia), or step (ib) is 0.01 to 0.1 moles per mole of the compound of formula (1) or the compound of formula (2), excluding methods that do not fall under this category. 【0076】 [I-41] A manufacturing method described in any one of items [I-1] to [I-40], wherein the oxygen concentration in step (i), step (ia), or step (ib) is 1 to 100% by volume, excluding methods that do not fall under this category. 【0077】 [I-42] A manufacturing method described in any one of items [I-1] to [I-40], wherein the oxygen concentration in step (i), step (ia), or step (ib) is 5 to 100% by volume, excluding methods that do not fall under this category. 【0078】 [I-43] A method according to any one of items [I-1] to [I-42], wherein the reaction in step (i), step (ia), or step (ib) is carried out in the presence of a solvent, wherein the solvent is selected from aromatic hydrocarbons, ethers, ketones, nitriles, and esters (preferably (C2-C4) alkanenitriles and (C1-C6) alkyl(C2-C4) carboxylates), excluding methods that do not fall under these categories. 【0079】 [I-44] A method according to any one of [I-1] to [I-42], wherein the reaction in step (i), step (ia), or step (ib) is carried out in the presence of a solvent, wherein the solvent is one or more (preferably one or two, more preferably one) selected from nitriles and esters (preferably (C2-C4) alkanenitriles and (C1-C6) alkyl(C2-C4) carboxylates), excluding methods that do not fall under this category. 【0080】 [I-45] A method according to any one of [I-1] to [I-42], wherein the reaction in step (i), step (ia), or step (ib) is carried out in the presence of a solvent, wherein the solvent is one or more (preferably one or two, more preferably one) selected from toluene, xylene, chlorobenzene, dichlorobenzene, chlorotoluene, tetrahydrofuran, dibutyl ether, acetone, methyl isobutyl ketone, acetonitrile, propionitrile, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, and pentyl acetate. 【0081】 [I-46] A method according to any one of [I-1] to [I-42], wherein the reaction of step (i), step (ia), or step (ib) is carried out in the presence of a solvent, wherein the solvent is one or more (preferably one or two, more preferably one) selected from acetonitrile, propionitrile, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, and pentyl acetate, except for methods that do not fall under this category. 【0082】 [I-47] A method of production according to any one of items [I-1] to [I-42], wherein the reaction in step (i), step (ia), or step (ib) is carried out in the presence of a solvent, wherein the solvent is acetonitrile or butyl acetate, excluding methods that do not fall under this category. 【0083】 [I-48] A method of production according to any one of items [I-1] to [I-42], wherein the reaction in step (i), step (ia), or step (ib) is carried out in the presence of a solvent, wherein the solvent is a (C1-C6) alkyl(C2-C4) carboxylate (preferably butyl acetate), excluding methods that do not fall under this category. 【0084】 [I-49] A manufacturing method described in any one of items [I-1] to [I-48], wherein the reaction of step (i), step (ia), or step (ib) is carried out in a batch manner, excluding methods that do not fall under this category. 【0085】 [I-50] A manufacturing method described in any one of items [I-1] to [I-48], wherein the reaction of step (i), step (ia), or step (ib) is carried out continuously using a tubular flow reactor, excluding methods that do not fall under this category. 【0086】 [I-51] A manufacturing method described in any one of items [I-1] to [I-48], wherein the reaction in step (i), step (ia), or step (ib) is carried out in a flow-through manner, excluding methods that do not fall under this category. 【0087】 [I-52] A method of manufacture according to any one of the items [I-1] to [I-51], wherein the batch reaction temperature is 10°C to 80°C, excluding methods that do not apply. 【0088】 [I-53] A manufacturing method according to any one of items [I-1] to [I-51], wherein the batch reaction temperature is 30°C to 70°C, excluding methods that do not apply. 【0089】 [I-54] A manufacturing method according to any one of items [I-1] to [I-51], wherein the reaction temperature of the flow-through system is 0°C to 120°C, excluding methods that do not fall under this category. 【0090】 [I-55] A manufacturing method according to any one of items [I-1] to [I-51], wherein the reaction temperature of the flow-through system is 40°C to 100°C, excluding methods that do not apply. 【0091】 [I-56] A method of manufacture according to any one of items [I-1] to [I-55], wherein the concentration of nitric acid in step (i), step (ia), or step (ib) is 10 to 90%, excluding methods that do not apply. 【0092】 [I-57] A method of manufacture according to any one of items [I-1] to [I-55], wherein the concentration of nitric acid in step (i), step (ia), or step (ib) is 30 to 80%, excluding methods that do not apply. 【0093】 [I-58] A method of production according to any one of items [I-1] to [I-57], wherein the oximing agent in step (ii), step (ii-a), or step (ii-b) is a hydroxylamine, a hydroxylamine salt, or an oxime compound, excluding methods that do not fall under this category. 【0094】 [I-59] A method of production according to any one of items [I-1] to [I-57], wherein the oximizing agent in step (ii), step (ii-a), or step (ii-b) is an aqueous solution of hydroxylamine, hydroxylamine hydrochloride, or hydroxylamine sulfate, excluding methods that do not fall under these categories. 【0095】 [I-60] A method according to any one of items [I-1] to [I-57], wherein the oximizing agent in step (ii), step (ii-a), or step (ii-b) is a 45% to 50% aqueous solution of hydroxylamine, hydroxylamine hydrochloride, or hydroxylamine sulfate, excluding methods that do not apply. 【0096】 [I-61] A method of manufacture according to any one of items [I-1] to [I-57], wherein the oximizing agent in step (ii), step (ii-a), or step (ii-b) is hydroxylamine hydrochloride or hydroxylamine sulfate, excluding methods that do not apply. 【0097】 [I-62] A method of production according to any one of items [I-1] to [I-57], wherein the oximizing agent in step (ii), step (ii-a), or step (ii-b) is hydroxylamine sulfate, excluding methods that do not apply. 【0098】 [I-63] A method according to any one of [I-1] to [I-62], wherein the oxime compound is of formula (8): 【0099】 [ka] (In the formula, R 4 and R 5 Each of these is independently a hydrogen atom; an optionally substituted (C1-C6) alkyl; an optionally substituted (C3-C6) cycloalkyl; an optionally substituted (C2-C6) alkenyl; an optionally substituted (C2-C6) alkynyl; a (C6-C10) aryl; or an optionally substituted (C6-C10) aryl(C1-C4) alkyl.) A method of production, excluding methods that do not apply. 【0100】 [I-64] A method according to any one of [I-1] to [I-63], wherein R of formula (8) 4 and R 5 The manufacturing method wherein each component is independently a hydrogen atom; (C1-C6) alkyl; (C3-C6) cycloalkyl; or (C6-C10) aryl, excluding methods that do not fall under these categories. 【0101】 [I-65] A method of manufacture according to any one of items [I-1] to [I-63], wherein formula (8) is acetone oxime, 2-butanone oxime, 2-pentanone oxime, or 3-pentanone oxime, excluding methods that do not apply. 【0102】 [I-66] A method of production according to any one of items [I-1] to [I-63], wherein formula (8) is acetone oxime or 2-butanone oxime (preferably acetone oxime), excluding methods that do not apply. 【0103】 [I-67] A method according to any one of [I-1] to [I-63], wherein R of formula (8) 4 and R 5 A method for producing a compound in which compounds bond to each other to form a ring, excluding methods that do not fall under this category. 【0104】 [I-68] A method of production according to any one of items [I-1] to [I-63], wherein formula (8) is cyclopropanone oxime, cyclobutanone oxime, cyclopentanone oxime, or cyclohexanone oxime, excluding methods that do not fall under any of the above. 【0105】 [I-69] A method according to any one of items [I-1] to [I-68], wherein the amount of oximizing agent used in step (ii), step (ii-a), or step (ii-b) is 0.9 to 1.5 moles in terms of hydroxylamine (NH2OH) per mole of compound (3) or compound (4), excluding methods that do not fall under this category. 【0106】 [I-70] A method according to any one of items [I-1] to [I-68], wherein the amount of oximizing agent used in step (ii), step (ii-a), or step (ii-b) is 1.0 to 1.3 moles in terms of hydroxylamine (NH2OH) per mole of compound (3) or compound (4), excluding methods that do not fall under this category. 【0107】 [I-71] A method of manufacture according to any one of items [I-1] to [I-70], wherein the reaction of step (ii), step (ii-a), or step (ii-b) is carried out in the presence of a neutralizing agent, excluding methods that do not fall under this category. 【0108】 [I-72] A method of manufacture according to any one of items [I-1] to [I-71], wherein the neutralizing agent in step (ii), step (ii-a), or step (ii-b) is sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, or potassium bicarbonate, excluding methods that do not fall under this category. 【0109】 [I-73] A method of manufacture according to any one of items [I-1] to [I-71], wherein the neutralizing agent in step (ii), step (ii-a), or step (ii-b) is sodium hydroxide, excluding methods that do not apply. 【0110】 [I-74] A method according to any one of items [I-1] to [I-73], wherein the amount of neutralizing agent used in step (ii), step (ii-a), or step (ii-b) is 0.5 to 1.5 moles (preferably 0.9 to 1.5 moles) per mole of the compound of formula (3) or the compound of formula (4), excluding methods that do not apply. 【0111】 [I-75] A method according to any one of items [I-1] to [I-73], wherein the amount of neutralizing agent used in step (ii), step (ii-a), or step (ii-b) is 1.0 to 1.3 moles per mole of the compound of formula (3) or the compound of formula (4), excluding methods that do not apply. 【0112】 [I-76] A method according to any one of [I-1] to [I-75], wherein the reaction in step (ii), step (ii-a), or step (ii-b) is carried out in the presence of a solvent selected from aromatic hydrocarbons (preferably (C2-C4) alkanenitriles, (C1-C6) alkyl(C2-C4) carboxylates, and (C1-C3) dichloroalkanes), ethers, ketones, nitriles, esters, and halogenated aliphatic hydrocarbons, excluding methods that do not fall under these categories. 【0113】 [I-77] A method according to any one of [I-1] to [I-75], wherein the reaction in step (ii), step (ii-a), or step (ii-b) is carried out in the presence of one or more (preferably one or two, more preferably one) solvents selected from nitriles, esters, and halogenated aliphatic hydrocarbons (preferably (C2-C4) alkanenitriles, (C1-C6) alkyl(C2-C4) carboxylates, and (C1-C3) dichloroalkanes), excluding methods that do not fall under this category. 【0114】 [I-78] A method according to any one of items [I-1] to [I-75], wherein the reaction in step (ii), step (ii-a), or step (ii-b) is carried out in the presence of a solvent, and the solvent is an ester or a halogenated aliphatic hydrocarbon (preferably (C1-C6) alkyl(C2-C4) carboxylate or (C1-C3) dichloroalkane), excluding methods that do not fall under this category. 【0115】 [I-79] A method of production according to any one of items [I-1] to [I-75], wherein the reaction in step (ii), step (ii-a), or step (ii-b) is carried out in the presence of a solvent, and the solvent is an ester (preferably a (C1-C6) alkyl(C2-C4) carboxylate), excluding methods that do not fall under this category. 【0116】 [I-80] A method according to any one of [I-1] to [I-75], wherein the reaction of step (ii), step (ii-a), or step (ii-b) is carried out in the presence of one or more (preferably one or two, more preferably one) selected from toluene, xylene, chlorobenzene, dichlorobenzene, chlorotoluene, tetrahydrofuran, dibutyl ether, acetone, methyl isobutyl ketone, acetonitrile, propionitrile, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, pentyl acetate, and dichloromethane. 【0117】 [I-81] A method according to any one of [I-1] to [I-75], wherein the reaction of step (ii), step (ii-a), or step (ii-b) is carried out in the presence of one or more (preferably one or two, more preferably one) selected from acetonitrile, butyl acetate, and dichloromethane. 【0118】 [I-82] A method of production according to any one of items [I-1] to [I-75], wherein the reaction in step (ii), step (ii-a), or step (ii-b) is carried out in the presence of a solvent, wherein the solvent is butyl acetate or dichloromethane, excluding methods that do not fall under this category. 【0119】 [I-83] A method of production according to any one of items [I-1] to [I-75], wherein the reaction in step (ii), step (ii-a), or step (ii-b) is carried out in the presence of a solvent, wherein the solvent is butyl acetate, excluding methods that do not apply. 【0120】 [I-84] A method of production according to any one of items [I-1] to [I-83], wherein the reaction in step (ii), step (ii-a), or step (ii-b) is carried out in the presence of an aqueous solvent, excluding methods that do not fall under this category. 【0121】 [I-85] A manufacturing method according to any one of items [I-1] to [I-84], wherein the reaction in step (ii), step (ii-a), or step (ii-b) is carried out at 0°C to 80°C, excluding methods that do not fall under this category. 【0122】 [I-86] A manufacturing method according to any one of items [I-1] to [I-84], wherein the reaction in step (ii), step (ii-a), or step (ii-b) is carried out at 10°C to 50°C, excluding methods that do not fall under this category. 【0123】 [I-87] A method according to any one of [I-1] to [I-86], wherein the acid catalyst in step (iii), step (iii-a), or step (iii-b) is one or more (preferably 1 to 3, more preferably 1 or 2, and even more preferably 1) acid catalysts selected from the group consisting of mineral acids, carboxylic acids, and sulfonic acids, excluding methods that do not fall under this category. 【0124】 [I-88] A method of production according to any one of items [I-1] to [I-86], wherein the acid catalyst in step (iii), step (iii-a), or step (iii-b) is nitric acid, trifluoroacetic acid, maleic acid, or p-toluenesulfonic acid, excluding methods that do not fall under these categories. 【0125】 [I-89] A method of production according to any one of items [I-1] to [I-86], wherein the acid catalyst in step (iii), step (iii-a), or step (iii-b) is nitric acid, excluding methods that do not apply. 【0126】 [I-90] A method of production according to any one of items [I-1] to [I-86], wherein the acid catalyst in step (iii), step (iii-a), or step (iii-b) is trifluoroacetic acid, excluding methods that do not apply. 【0127】 [I-91] A method of production according to any one of items [I-1] to [I-86], wherein the acid catalyst in step (iii), step (iii-a), or step (iii-b) is maleic acid, excluding methods that do not apply. 【0128】 [I-92] A method according to any one of items [I-1] to [I-91], wherein the amount of acid catalyst used in step (iii), step (iii-a), or step (iii-b) is 0.01 to 0.60 moles per mole of the compound of formula (5) or the compound of formula (6), excluding methods that do not apply. 【0129】 [I-93] A method according to any one of items [I-1] to [I-91], wherein the amount of acid catalyst used in step (iii), step (iii-a), or step (iii-b) is 0.05 to 0.40 moles per mole of the compound of formula (5) or the compound of formula (6), excluding methods that do not apply. 【0130】 [I-94] A method according to any one of items [I-1] to [I-93], wherein the reaction of step (iii), step (iii-a), or step (iii-b) is carried out in the absence of a base catalyst. 【0131】 [I-95] A method according to any one of items [I-1] to [I-93], wherein the reaction of step (iii), step (iii-a), or step (iii-b) is carried out in the presence of a base catalyst. 【0132】 [I-96] A method according to any one of items [I-1] to [I-95], wherein the reaction in step (iii), step (iii-a), or step (iii-b) is carried out in the presence of the same equivalent amount of base catalyst as the equivalent amount of acid catalyst. 【0133】 [I-97] A method according to any one of items [I-1] to [I-95], wherein the reaction in step (iii), step (iii-a), or step (iii-b) is carried out in the presence of a base catalyst in an amount less than the equivalent amount of the acid catalyst. 【0134】 [I-98] A method according to any one of items [I-1] to [I-95], wherein the reaction in step (iii), step (iii-a), or step (iii-b) is carried out in the presence of 0 to 1 equivalent of a base catalyst per 1 equivalent of an acid catalyst. 【0135】 [I-99] A method according to any one of items [I-1] to [I-95], wherein the reaction in step (iii), step (iii-a), or step (iii-b) is carried out in the presence of a base catalyst in an amount of more than 0 equivalents and less than or equal to 1 equivalent per equivalent of an acid catalyst. 【0136】 [I-100] A method according to any one of items [I-1] to [I-95], wherein the reaction in step (iii), step (iii-a), or step (iii-b) is carried out in the presence of 0.1 to 0.5 equivalents of base catalyst per 1 equivalent of acid catalyst. 【0137】 [I-101] A method according to any one of items [I-1] to [I-95], wherein the reaction in step (iii), step (iii-a), or step (iii-b) is carried out in the presence of 0.2 to 0.4 equivalents of base catalyst per 1 equivalent of acid catalyst. 【0138】 [I-102] A method according to any one of items [I-1] to [I-101], wherein the base catalyst in step (iii), step (iii-a), or step (iii-b) is a secondary amine. 【0139】 [I-103] A method according to any one of items [I-1] to [I-101], wherein the base catalyst in step (iii), step (iii-a), or step (iii-b) is N-methylaniline. 【0140】 [I-104] A method according to any one of [I-1] to [I-103], wherein the amount of base catalyst used in step (iii), step (iii-a), or step (iii-b) is 0.01 to 0.60 moles per mole of the compound of formula (5) or the compound of formula (6). 【0141】 [I-105] A method according to any one of [I-1] to [I-103], wherein the amount of base catalyst used in step (iii), step (iii-a), or step (iii-b) is 0.05 to 0.40 moles per mole of compound of formula (5) or compound of formula (6). 【0142】 [I-106] A method according to any one of [I-1] to [I-105], wherein the reaction in step (iii), step (iii-a), or step (iii-b) is carried out in the presence of a solvent selected from aromatic hydrocarbons, ethers, ketones, nitriles, esters, and halogenated aliphatic hydrocarbons (preferably (C2-C4) alkanenitriles, (C1-C6) alkyl(C2-C4) carboxylates, and (C1-C3) dichloroalkanes), excluding methods that do not fall under these categories. 【0143】 [I-107] A method according to any one of [I-1] to [I-105], wherein the reaction in step (iii), step (iii-a), or step (iii-b) is carried out in the presence of one or more (preferably one or two, more preferably one) solvents selected from nitriles, esters, and halogenated aliphatic hydrocarbons (preferably (C2-C4) alkanenitriles, (C1-C6) alkyl(C2-C4) carboxylates, and (C1-C3) dichloroalkanes), excluding methods that do not fall under this category. 【0144】 [I-108] A method according to any one of items [I-1] to [I-105], wherein the reaction in step (iii), step (iii-a), or step (iii-b) is carried out in the presence of a solvent, and the solvent is an ester or a halogenated aliphatic hydrocarbon (preferably (C1-C6) alkyl(C2-C4) carboxylate or (C1-C3) dichloroalkane), excluding methods that do not fall under this category. 【0145】 [I-109] A method of production according to any one of items [I-1] to [I-105], wherein the reaction in step (iii), step (iii-a), or step (iii-b) is carried out in the presence of a solvent, and the solvent is an ester (preferably a (C1-C6) alkyl(C2-C4) carboxylate), excluding methods that do not fall under this category. 【0146】 [I-110] A method according to any one of [I-1] to [I-105], wherein the reaction in step (iii), step (iii-a), or step (iii-b) is carried out in the presence of one or more (preferably one or two, more preferably one) selected from toluene, xylene, chlorobenzene, dichlorobenzene, chlorotoluene, tetrahydrofuran, dibutyl ether, acetone, methyl isobutyl ketone, acetonitrile, propionitrile, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, pentyl acetate, and dichloromethane. 【0147】 [I-111] A method according to any one of [I-1] to [I-105], wherein the reaction of step (iii), step (iii-a), or step (iii-b) is carried out in the presence of one or more (preferably one or two, more preferably one) selected from acetonitrile, butyl acetate, and dichloromethane. 【0148】 [I-112] A method of production according to any one of items [I-1] to [I-105], wherein the reaction in step (iii), step (iii-a), or step (iii-b) is carried out in the presence of a solvent, wherein the solvent is butyl acetate or dichloromethane, excluding methods that do not fall under this category. 【0149】 [I-113] A method according to any one of items [I-1] to [I-105], wherein the reaction in step (iii), step (iii-a), or step (iii-b) is carried out in the presence of a solvent, wherein the solvent is butyl acetate, excluding methods that do not apply. 【0150】 [I-114] A method of production according to any one of items [I-1] to [I-113], wherein the reaction in step (iii), step (iii-a), or step (iii-b) is carried out in the presence of an aqueous solvent, excluding methods that do not fall under this category. 【0151】 [I-115] A method according to any one of items [I-1] to [I-114], wherein the reaction in step (iii), step (iii-a), or step (iii-b) is carried out without a solvent, excluding methods that do not fall under this category. 【0152】 [I-116] A manufacturing method according to any one of items [I-1] to [I-115], wherein the reaction in step (iii), step (iii-a), or step (iii-b) is carried out at -30°C to 160°C, excluding methods that do not fall under this category. 【0153】 [I-117] A manufacturing method according to any one of items [I-1] to [I-115], wherein the reaction in step (iii), step (iii-a), or step (iii-b) is carried out at -10°C to 120°C, excluding methods that do not fall under this category. 【0154】 [I-118] A manufacturing method according to any one of items [I-1] to [I-115], wherein the reaction in step (iii), step (iii-a), or step (iii-b) is carried out at 0°C to 100°C, excluding methods that do not fall under this category. 【0155】 [I-119] A method according to any one of items [I-1] to [I-118], wherein the reaction in step (ii) is carried out without isolating the compound of formula (3) or the compound of formula (4) produced in step (i), excluding methods that do not fall under this category. 【0156】 [I-120] A method according to any one of items [I-1] to [I-118], wherein the reaction of step (ii), step (ii-a), or step (ii-b) is carried out without isolating the compound of formula (3) or the compound of formula (4) produced in step (i), step (ia), or step (ib), excluding methods that do not apply. 【0157】 [I-121] A method according to any one of items [I-1] to [I-118], wherein the reaction in step (iii) is carried out without isolating the compound of formula (5) or the compound of formula (6) produced in step (ii), excluding methods that do not apply. 【0158】 [I-122] A method according to any one of items [I-1] to [I-118], wherein the reaction in step (iii), step (iii-a), or step (iii-b) is carried out without isolating the compound of formula (5) or the compound of formula (6) produced in step (ii), step (ii-a), or step (ii-b), excluding methods that do not apply. 【0159】 [I-123] A method of production according to any one of items [I-1] to [I-118], wherein the subsequent step is carried out without isolating the product, excluding methods that do not fall under this category. 【0160】 [I-124] A manufacturing method according to any one of items [I-1] to [I-123], wherein the reactions of step (i) and step (ii) are carried out in a one-pot process, excluding methods that do not fall under this category. 【0161】 [I-125] A manufacturing method according to any one of items [I-1] to [I-123], wherein the reaction of step (i), step (ia), or step (ib) and the reaction of the next step are carried out in a one-pot process, excluding methods that do not fall under this category. 【0162】 [I-126] A method according to any one of items [I-1] to [I-123], wherein the reactions of step (ii) and step (iii) are carried out in a one-pot process, excluding methods that do not apply. 【0163】 [I-127] A manufacturing method according to any one of items [I-1] to [I-123], wherein the reaction of step (ii), step (ii-a), or step (ii-b) and the reaction of the next step are carried out in a one-pot process, excluding methods that do not fall under this category. 【0164】 [I-128] A method of production according to any one of items [I-1] to [I-127], wherein the reaction of step (i), step (ia), or step (ib) and the corresponding reaction of step (ii), step (ii-a), or step (ii-b) are carried out in the presence of the same solvent, excluding methods that do not fall under this category. 【0165】 [I-129] A method of production according to any one of items [I-1] to [I-127], wherein the reaction of step (ii), step (ii-a), or step (ii-b) and the corresponding reaction of step (iii), step (iii-a), or step (iii-b) are carried out in the presence of the same solvent, excluding methods that do not fall under this category. 【0166】 [I-130] A method of production according to any one of items [I-1] to [I-127], wherein all steps of the reaction are carried out in the presence of the same solvent, excluding methods that do not fall under this category. 【0167】 [I-131] A method according to any one of items [I-1] to [I-130], wherein the organic solvent used in the reaction of step (i), step (ia), or step (ib) is the same as the organic solvent used in the corresponding reaction of step (ii), step (ii-a), or step (ii-b), excluding methods that do not fall under this category. 【0168】 [I-132] A method according to any one of items [I-1] to [I-130], wherein the organic solvent used in the reaction of step (ii), step (ii-a), or step (ii-b) is the same as the organic solvent used in the corresponding reaction of step (iii), step (iii-a), or step (iii-b), excluding methods that do not apply. 【0169】 [I-133] A method of production according to any one of items [I-1] to [I-130], wherein the same organic solvent is used in all reaction steps, excluding methods that do not fall under this category. 【0170】 [I-134] A method of production according to any one of items [I-1] to [I-133], wherein the reaction of step (i), step (ia), or step (ib) is carried out in the presence of an aqueous solvent, excluding methods that do not fall under this category. 【0171】 [I-135] A method of production according to any one of items [I-1] to [I-133], wherein the reaction in step (i), step (ia), or step (ib) is carried out in the presence of a solvent, the solvent being water, except for methods that do not apply. 【0172】 [I-136] A method according to any one of items [I-1] to [I-133], wherein the reaction in step (i), step (ia), or step (ib) is carried out in the presence of a solvent, the solvent being water, except for methods that do not apply. 【0173】 [I-137] A method of production according to any one of items [I-1] to [I-136], wherein the reaction in step (ii), step (ii-a), or step (ii-b) is carried out in the presence of a solvent, the solvent being water, excluding methods that do not apply. 【0174】 [I-138] A method according to any one of items [I-1] to [I-136], wherein the reaction in step (ii), step (ii-a), or step (ii-b) is carried out in the presence of a solvent, the solvent being water, except for methods that do not apply. 【0175】 [I-139] A method of production according to any one of items [I-1] to [I-138], wherein the reaction in step (iii), step (iii-a), or step (iii-b) is carried out in the presence of a solvent, the solvent being water, except for methods that do not apply. 【0176】 [I-140] A method according to any one of items [I-1] to [I-138], wherein the reaction in step (iii), step (iii-a), or step (iii-b) is carried out in the presence of a solvent, the solvent being water, except for methods that do not apply. 【0177】 [I-141] A method according to any one of items [I-1] to [I-140], wherein the oxygen in step (i), step (ia), or step (ib) is derived from an oxygen generator (such as nitric acid), excluding methods that do not fall under this category. 【0178】 A method according to any one of items [I-1] to [I-140], wherein the oxygen in step (i), step (ia), or step (ib) is generated from an oxygen generating agent (such as nitric acid), excluding methods that do not fall under this category. 【0179】 [I-143] A method of production according to any one of items [I-1] to [I-142], wherein the reaction in step (i), step (ia), or step (ib) is carried out by introducing an oxygen-containing gas, excluding methods that do not fall under this category. 【0180】 [I-144] A method of production according to any one of items [I-1] to [I-142], wherein the reaction in step (i), step (ia), or step (ib) is carried out by introducing oxygen, excluding methods that do not fall under this category. 【0181】 [I-145] The method described in any one of [I-1] to [I-144], R 1 , R 2 and R 3 A manufacturing method in which the compound is methyl, excluding methods that do not meet this requirement. 【0182】 [I-146] The method described in any one of [I-1] to [I-144], R 1 and R 2 A manufacturing method in which the substance is methyl. 【0183】 [II-1] A method for producing the compound of formula (7), comprising the following steps; Step (i) Reacting the compound of formula (1) or the compound of formula (2) in the presence of a metal catalyst, nitric acid, oxygen, and a nitroxyl radical compound to obtain the corresponding compound of formula (3) or the compound of formula (4): 【0184】 [ka] (In the formula, R 1 and R 2 Each of these is independently a substituted (C1-C6) alkyl, and R 3 This is a hydrogen atom; optionally substituted (C1-C6) alkyl; optionally substituted (C3-C6) cycloalkyl; optionally substituted (C6-C10) aryl; or optionally substituted (C6-C10) aryl(C1-C4) alkyl. Step (ii) React the compound of formula (3) or the compound of formula (4) with an oximating agent to obtain the corresponding compound of formula (5) or the compound of formula (6): 【0185】 [ka] (In the formula, R 1 , R 2 and R 3 This is as defined above. Step (iii) React the compound of formula (5) or the compound of formula (6) in the presence of an acid catalyst, or in the presence of both an acid catalyst and a base catalyst, to obtain the compound of formula (7): 【0186】 [ka] (In the formula, R 1 , R 2 and R 3 This is as defined above. [II-2] A manufacturing method according to [II-1], wherein the metal catalyst is an iron catalyst or a copper catalyst. [II-3] A manufacturing method according to [II-1], wherein the metal catalyst is iron(III) chloride. [II-4] A method for producing the product as described in [II-1], wherein the nitroxyl radical compound is 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl. [II-5] The manufacturing method described in [II-1], R 1 , R 2 and R 3 A manufacturing method in which the substance is methyl. [II-6] A method for producing a compound of formula (3) or a compound of formula (4), comprising reacting a compound of formula (1) or a compound of formula (2) in the presence of a metal catalyst, nitric acid, oxygen, and a nitroxyl radical compound to obtain the corresponding compound of formula (3) or a compound of formula (4): 【0187】 [ka] 【0188】 (In the formula, R 1 and R 2 Each of these is independently a substituted (C1-C6) alkyl, and R 3 This is a hydrogen atom; optionally substituted (C1-C6) alkyl; optionally substituted (C3-C6) cycloalkyl; optionally substituted (C6-C10) aryl; or optionally substituted (C6-C10) aryl(C1-C4) alkyl. [II-7] A manufacturing method according to [II-6], wherein the metal catalyst is an iron catalyst or a copper catalyst. [II-8] A manufacturing method according to [II-6], wherein the metal catalyst is iron(III) chloride. [Effects of the Invention] 【0189】 The present invention provides a novel method for producing the compound of formula (7). According to the present invention, an efficient and industrially preferable method for producing the compound of formula (7) is provided. Furthermore, according to the present invention, the compound of formula (7) can be produced in high yield with simple operations. In addition, the present invention provides a novel method for producing the compound of formula (3) or the compound of formula (4). According to the present invention, a more industrially preferable method for producing the compound of formula (3) or the compound of formula (4) is provided. Furthermore, according to the present invention, by-products can be suppressed with simple operations, and the compound of formula (3) or the compound of formula (4) can be produced in high yield. 【0190】 Furthermore, the present invention can suppress the generation of by-products and / or waste, and improve atomic efficiency. As a result, the present invention provides a simple and inexpensive method for producing intermediates for herbicides such as pyroxasulfone on an industrial scale. Therefore, the method of the present invention is industrially preferable, economical, environmentally friendly, and has high industrial value. [Brief explanation of the drawing] 【0191】 [Figure 1]Figure 1 schematically shows an overview of the reaction apparatus of the present invention used in Example 11, in which a flow reaction was carried out. This is a schematic diagram of an example of a reaction apparatus for carrying out the manufacturing method of the present invention. [Figure 2] Figure 2 schematically shows an overview of the reaction apparatus of the present invention used in Example 55, in which a flow reaction was carried out. This is a schematic diagram of an example of a reaction apparatus for carrying out the manufacturing method of the present invention. [Figure 3] Figure 3 schematically shows an overview of the reaction apparatus of the present invention used in Example 56, in which a flow reaction was carried out. This is a schematic diagram of an example of a reaction apparatus for carrying out the manufacturing method of the present invention. [Modes for carrying out the invention] 【0192】 The present invention will be described in detail below. 【0193】 The terms and symbols used in this specification are explained below. 【0194】 Examples of halogen atoms include fluorine, chlorine, bromine, and iodine atoms. 【0195】 (Ca-Cb) means that the number of carbon atoms is between a and b. For example, in "(C1-C4)alkyl," "(C1-C4)" means that the alkyl group has 1 to 4 carbon atoms. 【0196】 In this specification, general terms such as “alkyl” are understood to include both linear and branched isomers such as butyl and tert-butyl. However, when a specific term such as “butyl” is used, it is specific to “n-butyl,” i.e., “n-butyl.” In other words, the specific term “butyl” means linear “n-butyl,” and branched isomers such as “tert-butyl” are referred to specifically where intended. 【0197】 The prefixes "n-", "s-" and "sec-", "i-", "t-" and "tert-", [neo-], "c-" and "cyc-", "o-", "m-", and "p-" have the following ordinary meanings: normal, secondary ("s-" and "sec-"), iso, tertiary ("t-" and "tert-"), neo, cyclo ("c-" and "cyc-"), ortho, meta, and para. 【0198】 In this specification, the following abbreviations may be used: "Me" stands for methyl. "Et" means ethyl. "Pr," "n-Pr," and "Pr-n" all refer to propyl (i.e., normal propyl). "i-Pr" and "Pr-i" both mean isopropyl. "Bu," "n-Bu," and "Bu-n" all refer to butyl (i.e., normal butyl). "s-Bu" and "Bu-s" refer to sec-butyl. "i-Bu" and "Bu-i" refer to isobutyl. "t-Bu" and "Bu-t" mean tert-butyl. "Pen," "n-Pen," and "Pen-n" all refer to pentyl (i.e., normal pentyl). "Hex," "n-Hex," and "Hex-n" all refer to hexyl (i.e., normal hexyl). "Dec," "n-Dec," and "Dec-n" all mean decile (i.e., normal decile). "c-Pr" and "Pr-c" stand for cyclopropyl. "c-Bu" and "Bu-c" refer to cyclobutyl. "c-Pen" and "Pen-c" refer to cyclopentyl. "c-Hex" and "Hex-c" refer to cyclohexyl. "Ph" stands for phenyl. "Bn" stands for benzyl. 【0199】 "Ac" means acetyl (CH3CO-). 【0200】 (C1-C6)alkyl means a straight-chain or branched-chain alkyl having 1 to 6 carbon atoms. Examples of (C1-C6)alkyl include, but are not limited to, methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, isobutyl, tert-butyl, pentyl, isopentyl, neopentyl, hexyl, etc. 【0201】 (C1-C4)alkyl means a straight-chain or branched-chain alkyl having 1 to 4 carbon atoms. Examples of (C1-C4)alkyl are appropriate examples among the above examples of (C1-C6)alkyl. 【0202】 (C1-C3)alkyl and similar expressions are understood similarly. 【0203】 (C2-C4)alkanenitrile means (C1-C3)alkyl-CN. Examples of (C2-C4)alkanenitrile are acetonitrile, propionitrile, butyronitrile, isobutyronitrile. For example, C2 alkanenitrile is acetonitrile. For example, propionitrile is C3 alkanenitrile. <^ 【0204】 (C1-C6)alkyl(C2-C4)carboxylate means (C1-C3)alkyl-COO-(C1-C6)alkyl, that is, (C1-C3)alkyl-C(=O)-O-(C1-C6)alkyl. Examples of (C1-C6)alkyl(C2-C4)carboxylate include, but are not limited to, methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate and its isomers, pentyl acetate and its isomers, hexyl acetate and its isomers, ethyl propionate, propyl propionate, isopropyl propionate, butyl propionate and its isomers, etc. For example, butyl acetate is (C4)alkyl(C2)carboxylate (that is, C4 alkyl C2 carboxylate). 【0205】 Examples of (C1-C3) dichloroalkanes include, but are not limited to, dichloromethane, 1,2-dichloroethane, etc. For example, dichloromethane is a C1 dichloroalkane. 【0206】 In one aspect, preferred examples of aromatic hydrocarbon derivatives are benzene optionally substituted by 1 to 3 substituents (preferably 1 or 2 substituents) selected from the group consisting of (C1-C3) alkyl and chlorine atoms, more preferred examples are toluene, xylene, chlorobenzene or dichlorobenzene, and even more preferred examples are toluene or xylene. The above may be applicable to all cases of the present invention. 【0207】 (C3-C6) cycloalkyl means cycloalkyl having 3 to 6 carbon atoms. Examples of (C3-C6) cycloalkyl are cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl. 【0208】 Examples of (C6-C10) aryl are phenyl, 1-naphthyl, and 2-naphthyl. (C6-C10) aryl (C1-C4) alkyl means (C1-C4 alkyl) substituted by (C6-10) aryl (where the C6-10 aryl moiety and the C1-C4 alkyl moiety have the same meaning as defined above). Examples of (C6-C10) aryl (C1-C4) alkyl include, but are not limited to, benzyl, 1-phenylethyl, 2-phenylethyl, 3-phenylpropyl, 4-phenylbutyl, naphthalen-1-ylmethyl, naphthalen-2-ylmethyl, etc. 【0209】 The cyclic hydrocarbon group means an aromatic or non-aromatic, monocyclic or polycyclic cyclic group in which all atoms constituting the ring are carbon atoms. 【0210】 In one embodiment, examples of cyclic hydrocarbon groups include, but are not limited to, aromatic or non-aromatic monocyclic, bicyclic, or tricyclic cyclic hydrocarbon groups with 3 to 14 members (preferably 5 to 14 members, more preferably 5 to 10 members). In another embodiment, examples of cyclic hydrocarbon groups include, but are not limited to, aromatic or non-aromatic monocyclic or bicyclic (preferably monocyclic) cyclic hydrocarbon groups with 4 to 8 members (preferably 5 to 6 members). 【0211】 Examples of cyclic hydrocarbon groups include, but are not limited to, cycloalkyl and aryl groups. 【0212】 Aryl is an aromatic cyclic hydrocarbon group, as defined above. 【0213】 The cyclic hydrocarbon groups defined or illustrated above may, if possible, include both non-condensed cyclic (e.g., monocyclic or spirocyclic) and condensed cyclic groups. 【0214】 The cyclic hydrocarbon groups defined or exemplified above may be unsaturated, partially saturated, or saturated, if possible. 【0215】 A cyclic hydrocarbon group as defined or illustrated above is also called a carbocyclic group. 【0216】 A carbocyclic ring is a ring corresponding to a cyclic hydrocarbon group as defined or illustrated above. 【0217】 In this specification, the term "substituents" in "may be substituted" is not particularly limited, as long as they are chemically acceptable and exhibit the effects of the present invention. 【0218】 In this specification, examples of “substituents” with respect to the term “may be substituted” include, but are not limited to, one or more substituents (preferably 1 to 4 substituents) independently selected from substituent group (a). 【0219】 The substituent group (a) is a group containing a halogen atom; a nitro group; a cyano group; a hydroxy group; an amino group; (C1-C6) alkyl; (C3-C6) cycloalkyl; phenyl; phenoxy, etc. 【0220】 In addition, one or more substituents (preferably 1 to 4 substituents) independently selected from the substituent group (a) may each independently have one or more substituents (preferably 1 to 4 substituents) independently selected from the substituent group (b). 【0221】 Here, the substituent group (b) is the same as the substituent group (a). 【0222】 In this specification, compounds having isomers include all isomers and any mixture thereof in any ratio. For example, xylene includes o-xylene, m-xylene, p-xylene, and any mixture thereof in any ratio. For example, dichlorobenzene includes o-dichlorobenzene, m-dichlorobenzene, p-dichlorobenzene, and any mixture thereof in any ratio. 【0223】 For example, when a compound has geometric isomers (cis-trans isomers, i.e., E / Z isomers), the (E)-isomer (anti-isomer), the (Z)-isomer (syn-isomer), and any mixture thereof in any ratio are included in the scope of the present invention. Specifically, for example, the compound of formula (5): 【0224】 【Chemical formula】 【0225】 The compound may be only the compound of formula (5-E): 【0226】 【Chemical formula】 / / 保留标签,不做翻译修改 【0227】 or may be only the compound of formula (5-Z): 【0228】 < [ka] 【0229】 The compound may consist solely of the above formula (5-E) and the above formula (5-Z), or it may be any mixture thereof in any proportion. 【0230】 Furthermore, more specifically, for example, equation (6): 【0231】 [ka] 【0232】 The compound is given by formula (6-E): 【0233】 [ka] 【0234】 It may be just the compound of formula (6-Z): 【0235】 [ka] 【0236】 The compound may consist solely of the above formula (6-E) and the above formula (6-Z), or it may be any mixture thereof in any proportion. 【0237】 In this specification, the dashed line in chemical formulas means the following: For example, if a compound has geometric isomers (cis-trans isomers, i.e., E / Z isomers), then the (E)-isomer (anti-isomer), the (Z)-isomer (syn-isomer), and any proportion of mixtures thereof are included in the chemical formula with the dashed line. 【0238】 In one aspect, the method according to the present invention is based on the following scheme (wherein R 1 , R 2 and R3 This is as described in [I-1] above. ) 【0239】 [ka] 【0240】 (Step (i)) Let's explain process (i). All descriptions in step (i) below apply to steps (ia) and (ib), unless otherwise specified. 【0241】 The reaction in step (i) is an oxidation reaction. The reaction in step (i) is also called the oxidation step. Step (i) is a manufacturing method that includes reacting a compound of formula (1) or formula (2) in the presence of a metal catalyst, nitric acid, oxygen, and a nitroxyl radical compound. 【0242】 [ka] 【0243】 (In the formula, R 1 , R 2 and R 3 (This is as defined above.) 【0244】 (Raw materials for process (i)) The compound of formula (1) or the compound of formula (2) is used as a raw material. The compound of formula (1) and the compound of formula (2) are known compounds, or can be produced from known compounds in accordance with known methods. Specific examples of compounds of formula (1) include, but are not limited to, the following: 3-methyl-1,3-butanediol (also called 3-methylbutane-1,3-diol or 3-hydroxy-3-methylbutanol), 3-methoxy-3-methylbutanol, 3-ethoxy-3-methylbutanol, 3-methyl-3-propoxybutanol, 3-isopropoxy-3-methylbutanol, 3-butoxy-3-methylbutanol, 3-isobutoxy-3-methylbutanol, 3-(sec-butoxy)-3-methylbutanol, 3-(benzyloxy)-3-methylbutanol, etc. From the viewpoint of the usefulness of the product, a preferred specific example of a compound of formula (1) is 3-methoxy-3-methylbutanol. From the same viewpoint as above, a preferred specific example of the compound of formula (2) is, but is not limited to, 3-methyl-2-butenol (also known as prenol). 【0245】 (Oxygen in process (i)) The oxidation reaction of the present invention is carried out in the presence of oxygen. Oxygen may be used as an oxygen-containing gas (e.g., including a mixed gas such as pure oxygen and air), or as an oxygen-generating agent (e.g., nitric acid), or as a combination thereof. Accordingly, the method of the present invention may include introducing and reacting at least one (preferably one to three, more preferably one or two) selected from the group consisting of oxygen-containing gases (e.g., pure oxygen, air) and oxygen-generating agents (e.g., nitric acid). As the oxygen-containing gas, oxygen or air may be used diluted with an inert gas (e.g., nitrogen, carbon dioxide, argon, preferably nitrogen, carbon dioxide, more preferably nitrogen). 【0246】 (Oxygen concentration in process (i)) The oxygen concentration introduced can be any concentration as long as the reaction proceeds. However, from the viewpoint of yield, suppression of by-products, and economic efficiency, it is preferably 1% to 100% by volume, more preferably 5% to 100% by volume. The concentration of oxygen generated from an oxygen-generating agent such as nitric acid may also be the same as described above. 【0247】 (Nitroxyl radical compound in step (i)) Conventionally known compounds can be used as nitroxyl radical compounds. Examples of nitroxyl radical compounds include TEMPO-based catalysts (e.g., 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO), 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl (4-hydroxyTEMPO or 4-OH-TEMPO), 4-methoxy-2,2,6,6-tetramethylpiperidine 1-oxyl (4-MeOTEMPO), 4-acetoxy-2,2,6,6-tetramethylpiperidine 1-oxyl (4-AcOTEMPO), 4-acetamido-2,2,6,6-tetramethylpiperidine 1-oxyl These include methylpiperidine 1-oxyl, 4-benzyloxy-2,2,6,6-tetramethylpiperidine 1-oxyl, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine 1-oxyl (4-BzOTEMPO), etc., AZADO-based catalysts (2-azaadamantane-N-oxyl (AZADO), 1-methyl-2-azaadamantane-N-oxyl, etc.), azabicyclo[3,3,1]nonane-N-oxyl, etc., and these can be used individually or as a mixture of two or more. Preferably, they are 2,2,6,6-tetramethylpiperidine 1-oxyl and 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl. 【0248】 The amount of nitroxyl radical compound used can be any amount as long as the reaction proceeds. However, from the viewpoint of yield, suppression of by-products, and economic efficiency, for example, it is usually 0.0001 moles to 0.3 moles, preferably 0.001 moles to 0.1 moles, per mole of compound of formula (1) or compound of formula (2) (alcohol compound). 【0249】 (Metal catalyst in step (i)) In one embodiment, from the viewpoint of reactivity, yield, and economic efficiency, preferred examples of metal catalysts for the oxidation reaction of the present invention include copper catalysts and iron catalysts. Specific examples of metal catalysts for the oxidation reaction of the present invention include copper catalysts (e.g., copper(II) nitrate, catalysts containing copper(II) chloride and nitric acid, catalysts containing copper(II) bromide and nitric acid, catalysts containing copper(II) iodide and nitric acid), iron catalysts (e.g., iron(III) nitrate, catalysts containing iron(III) chloride and nitric acid, catalysts containing iron(III) bromide and nitric acid), more preferably catalysts containing copper(II) nitrate and nitric acid, catalysts containing iron(III) chloride and nitric acid, catalysts containing iron(III) bromide and nitric acid, iron(III) nitrate, even more preferably iron(III) nitrate, catalysts containing iron(III) chloride and nitric acid, and even more preferably catalysts containing iron(III) chloride and nitric acid. In another aspect, from the same viewpoint as above, preferred examples of metal catalysts for the oxidation reaction of the present invention include copper catalysts and iron catalysts. Specific examples of metal catalysts for the oxidation reaction of the present invention include copper catalysts (e.g., copper(II) nitrate, copper(II) chloride, copper(II) bromide, copper(II) iodide), iron catalysts (e.g., iron(III) nitrate, iron(III) chloride, iron(III) bromide), more preferably copper(II) nitrate, iron(III) chloride, iron(III) bromide, iron(III) nitrate, even more preferably iron(III) nitrate, iron(III) chloride, and particularly preferably iron(III) chloride. Iron(III) chloride is cheaper than iron(III) nitrate, making it industrially and economically superior. Furthermore, iron(III) chloride is less hygroscopic than iron(III) nitrate and easier to handle, making it easier to use industrially. 【0250】 The metal catalyst may be in any form, and salts or hydrates thereof can also be used. 【0251】 The amount of metal catalyst used can be any amount as long as the reaction proceeds. However, from the viewpoint of yield, suppression of by-products, and economic efficiency, it is preferable to use 0.0001 moles to 0.5 moles, more preferably 0.001 moles to 0.3 moles, and even more preferably 0.01 moles to 0.1 moles per mole of compound of formula (1) or compound of formula (2) (alcohol compound). 【0252】 (Nitric acid in step (i)) The oxidation reaction of the present invention is carried out in the presence of nitric acid. In one embodiment, nitric acid is preferably used together with copper(II) chloride, copper(II) bromide, copper(II) iodide, iron(III) chloride, and iron(III) bromide. In another embodiment, not limited to the foregoing, nitric acid is used together with a metal catalyst. 【0253】 The concentration of nitric acid can be appropriately selected by those skilled in the art. It is preferable to use an aqueous solution of nitric acid. There are no particular restrictions on the concentration of nitric acid in the aqueous solution, but it is preferably 0.1 to 100%, more preferably 1 to 100%, even more preferably 10 to 90%, and still more preferably 30 to 80%. 【0254】 Nitric acid may be part of a catalyst (e.g., a co-catalyst, a promoter), an oxidizing agent, an oxygen-generating agent, or a combination of these. The amount of nitric acid used can be any amount as long as the reaction proceeds. However, from the viewpoint of yield, suppression of by-products, and economic efficiency, in one embodiment, the amount is usually 0.01 moles to 1 mole, preferably 0.02 moles to 0.9 moles, and more preferably 0.02 moles to 0.8 moles per mole of the compound of formula (1) or the compound of formula (2) (alcohol compound). In another embodiment, from the same viewpoint as above, the amount is usually 0.01 moles to 0.1 mole, preferably 0.02 moles to 0.09 moles, and more preferably 0.02 moles to 0.05 moles. In yet another embodiment, from the same viewpoint as above, the amount is usually 0.5 moles to 1 mole, preferably 0.5 moles to 0.9 moles, and more preferably 0.5 moles to 0.8 moles. 【0255】 (Acid in step (i)) In one embodiment, from the viewpoint of reactivity, yield, and economic efficiency, it is preferable to use an acid in the oxidation reaction of the present invention. Examples of acids include carboxylic acids. Specific examples include preferably acetic acid, propionic acid, butanoic acid, isobutanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, and benzoic acid, more preferably acetic acid, propionic acid, and benzoic acid, even more preferably acetic acid and propionic acid, and even more preferably acetic acid, but are not limited to these. In another embodiment, the oxidation reaction of the present invention may or may not use an acid. When an acid is used, examples of the acid are as described above. 【0256】 The amount of acid used can be any amount as long as the reaction proceeds. However, when using acid, from the viewpoint of yield, suppression of by-products, and economic efficiency, the amount is usually 0.1 moles to 10 moles, preferably 0.2 moles to 5 moles, more preferably 0.5 moles to 3 moles, and even more preferably 1 mole to 2 moles per mole of compound of formula (1) or compound of formula (2) (alcohol compound). 【0257】 (base in step (i)) In one embodiment, from the viewpoint of reactivity, yield, and economic efficiency, the oxidation reaction of the present invention is preferably carried out using a base. Examples of bases include aromatic heterocyclic compounds having a nitrogen atom. Specific examples preferably include N-methylimidazole (NMI), N-methylpyrazole, pyridine, N,N-dimethylaminopyridine (DMAP), and 2,2'-bipyridyl (BiPy), and more preferably include N-methylimidazole and 2,2'-bipyridyl, but are not limited to these. In another embodiment, the oxidation reaction of the present invention may or may not use a base. When a base is used, examples of bases are as described above. 【0258】 The form of the base may be any form, as long as the reaction proceeds. The form of the base can be appropriately selected by a person skilled in the art. 【0259】 The amount of base used can be any amount as long as the reaction proceeds. However, when using a base, from the viewpoint of yield, suppression of by-products, and economic efficiency, it is usually 0.001 moles to 1 mole, preferably 0.001 moles to 0.3 moles, and more preferably 0.01 moles to 0.1 moles per mole of compound of formula (1) or compound of formula (2) (alcohol compound). 【0260】 (Solvent in step (i)) From the viewpoint of ensuring the smooth progress of the reaction, the oxidation reaction of the present invention is preferably carried out in the presence of a solvent. The solvent for the oxidation reaction of the present invention may be any solvent as long as the reaction proceeds. Examples of solvents include, but are not limited to, ethers (e.g., tetrahydrofuran (THF), 1,4-dioxane, diisopropyl ether, dibutyl ether, di-tert-butyl ether), carboxylic acid esters (e.g., (C1-C6) alkyl(C2-C4) carboxylates (specifically, for example, methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate and its isomers, pentyl acetate and its isomers)), ketones (e.g., acetone, 2-butanone, methyl isobutyl ketone), aromatic hydrocarbon derivatives (e.g., benzene, toluene, xylene, chlorobenzene, dichlorobenzene, chlorotoluene), nitriles (e.g., (C2-C4) alkanenitriles (specifically, for example, acetonitrile, propionitrile) and any combination thereof in any proportion. 【0261】 From the viewpoint of yield, suppression of by-products, and economic efficiency, in one embodiment, preferred examples of solvents for the oxidation reaction of the present invention include carboxylic acid esters (preferably (C1-C6)alkyl(C2-C4)carboxylates), nitriles (preferably (C1-C6)alkyl(C2-C4)carboxylates), and any combination thereof in any proportion. Preferred specific examples of solvents for the oxidation reaction of the present invention include methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate and its isomers, acetonitrile, propionitrile, and any combination thereof in any proportion. More preferred specific examples are methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate and its isomers, acetonitrile, and any combination thereof in any proportion, further preferably butyl acetate and its isomers or acetonitrile, and even more preferably butyl acetate or acetonitrile. In another embodiment, preferred examples of solvents for the oxidation reaction of the present invention are carboxylic acid esters (preferably (C1-C6)alkyl(C2-C4)carboxylates). More preferred specific examples include methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate and its isomers and any combination thereof in any proportion, more preferably butyl acetate and its isomers, and even more preferably butyl acetate. 【0262】 In addition, the reaction in step (i) may be carried out in the presence of an aqueous solvent. For example, water derived from an aqueous nitric acid solution (e.g., 69% nitric acid) used as an oxygen-evolving agent can be understood as an aqueous solvent. 【0263】 The amount of solvent used may be any amount, as long as the reaction system can be sufficiently stirred. From the viewpoint of yield, suppression of by-products, and economic efficiency, the amount of solvent is 0 to 10 L, preferably 0.1 to 5 L, more preferably 0.3 to 2 L, per mole of compound (1) or compound (2), but is not limited to these amounts. When using a combination of two or more solvents, the proportions of the two or more solvents may be any proportion as long as the reaction proceeds. The solvents may be a single layer or separated into two layers as long as the reaction proceeds. 【0264】 (Product of step (i); compound of formula (3) or compound of formula (4)) The product of step (i) is a compound of formula (3) or formula (4) that corresponds to the compound of formula (1) or formula (2) used as a raw material. Specific examples, preferred specific examples, and more preferred specific examples are described below as raw materials for step (ii). 【0265】 The compound of formula (3) or the compound of formula (4) obtained in step (i) can be used as a raw material in step (ii). The compound of formula (3) or the compound of formula (4) obtained in step (i) may be isolated and used in the next step, further purified and used in the next step, or used in the next step without isolation. However, it is more efficient to use it in the next step without isolation. 【0266】 (Step (ii)) Process (ii) will be explained. All descriptions in step (ii) below apply to steps (ii-a) and (ii-b), unless otherwise specified. 【0267】 The reaction in step (ii) is oximation. The reaction in step (ii) is also called the oximation step. Step (ii) is a step in which the compound of formula (3) or the compound of formula (4) is reacted with an oximing agent to produce the compound of formula (5) or the compound of formula (6). 【0268】 [ka] 【0269】 (In the formula, R 1 , R 2 and R 3 (This is as defined above.) 【0270】 (Raw materials for step (ii); compound of formula (3) or compound of formula (4)) As a raw material for step (ii), the compound of formula (3) or the compound of formula (4) is used. The compound of formula (3) or the compound of formula (4) is a known compound, or can be produced from a known compound in accordance with a known method. Specific examples of compounds of formula (3) or formula (4) include, but are not limited to, the following: 3-methyl-2-butenal (also known as prenal), 3-hydroxy-3-methylbutanal (also known as 3-hydroxy-3-methylbutan-1-al), 3-methoxy-3-methylbutanal, 3-ethoxy-3-methylbutanal, 3-methyl-3-propoxybutanal, 3-isopropoxy-3-methylbutanal, 3-butoxy-3-methylbutanal, 3-isobutoxy- 3-Methylbutanal, 3-(sec-butoxy)-3-methylbutanal, 3-methyl-3-phenoxybutanal, 3-(benzyloxy)-3-methylbutanal, 3-hydroxy-3-methylpentanal, 3-ethyl-3-hydroxypentanal, 3-hydroxy-3,4-dimethylpentanal, 3-hydroxy-3,4,4-trimethylpentanal, 4-chloro-3-hydroxy-3-methylbutanal, 4,4,4-trifluoro-3-hydroxy-3-methylbutanal 3-hydroxy-3-methylheptanal, 3-hydroxy-3,7-dimethyl-6-octenal, 3-hydroxy-3,7-dimethyloctanal, 3-hydroxy-3,7-dimethyloctanal, 3-(9H-fluorene-9-ylidene)-3-hydroxypropanal, 3-hydroxy -3,3-diphenyl-2-propanal, 3-hydroxy-3,3-bis(4-methylphenyl)propanal, 3-hydroxy-3,3-bis(4-methoxyphenyl)propanal, 3-hydroxy-3,3-bis(4-chlorophenyl)propanal, 3-hydroxy-3-phenylbutanal, 3-hydroxy-3-(4-methylphenyl)butanal, 3-hydroxy-3-(4-methoxyphenyl)butanal, 3-hydroxy-3-(4-chlorophenyl)butanal, etc. From the viewpoint of the usefulness of the product, preferred specific examples of the compound of formula (3) or formula (4) are 3-hydroxy-3-methylbutanal and 3-methoxy-3-methylbutanal.From the viewpoint of the usefulness of the product, preferred specific examples of compounds of formula (3) are as follows: 3-hydroxy-3-methylbutanal (also called 3-hydroxy-3-methylbutan-1-ar), 3-methoxy-3-methylbutanal, 3-ethoxy-3-methylbutanal, 3-methyl-3-propoxybutanal, 3-isopropoxy-3-methylbutanal, 3-butoxy-3-methylbutanal, 3-isobutoxy-3-methylbutanal, 3-(sec-butoxy)-3-methylbutanal, 3-(benzyloxy)-3-methylbutanal, etc. From the same viewpoint as above, a more preferred specific example of a compound of formula (3) is 3-methoxy-3-methylbutanal. From the same viewpoint as above, a preferred specific example of the compound of formula (4) is 3-methyl-2-butenal (also known as prenal). 【0271】 (Oximing agent in process (ii)) Any oximing agent may be used in step (ii), as long as the reaction proceeds. Examples of oximing agents that can be used in step (ii) include hydroxylamine, hydroxylamine salts, and oxime compounds. The oximing agent is not particularly limited as long as the reaction proceeds and safety is ensured. Examples of hydroxylamine (free) include, but are not limited to, 50% aqueous hydroxylamine solution, 60% aqueous hydroxylamine solution, 70% aqueous hydroxylamine solution, 80% aqueous hydroxylamine solution, and 90% aqueous hydroxylamine solution. Generally, "50% aqueous hydroxylamine solution" is also called "Hydroxylamine (50% solution in water)". Examples of hydroxylamine salts include, but are not limited to, hydroxylamine hydrochloride, hydroxylamine sulfate, hydroxylamine nitrate (e.g., 50% aqueous solution), hydroxylamine carbonate, hydroxylamine phosphate, hydroxylamine acetate, and hydroxylamine oxalate. 【0272】 In this specification, oxime compounds used as oximing agents are represented by the following formula. 【0273】 [ka] 【0274】 In the formula, R 4 and R 5 Each of these is independently a hydrogen atom; (C1-C6) alkyl; (C3-C6) cycloalkyl; (C2-C6) alkenyl; (C2-C6) alkynyl; (C6-C10) aryl; or (C6-C10) aryl(C1-C4) alkyl, or R 4 and R 5 The two may be joined together to form a ring. 【0275】 The compound of formula (8) is a known compound, or can be produced from a known compound by a known method. R of the compound of formula (3) or the compound of formula (4) 4 and R 5 Specific examples of which do not form a ring include, but are not limited to, the following: Examples include formoxime, acetone oxime (also called acetoxime), 2-butanone oxime (methyl ethyl ketone oxime), methyl isopropyl ketone oxime, methyl tert-butyl ketone oxime, 2-pentanone oxime, 3-pentanone oxime, 1-cyclohexyl-1-propanone oxime, 2-hexanone oxime, 3-hexanone oxime, 3-heptanone oxime, 4-octanone oxime, 5-nonanone oxime, acetaldoxime, benzoaldoxime, acetophenone oxime, 4'-hydroxyacetophenone oxime, and benzophenone oxime. 【0276】 R of the compound of formula (3) or the compound of formula (4) 4 and R 5 Specific examples of non-conjugated systems forming a ring include, but are not limited to, the following: Examples include cyclopropanone oxime, cyclobutanone oxime, cyclopentanone oxime, cyclohexanone oxime, cycloheptanone oxime, cyclooctanone oxime, cyclononanone oxime, and cyclodecanone oxime. 【0277】 The oximizing agent used in step (ii) may be used alone or in any combination of two or more agents in any proportion. The form of the oximizing agent used in step (i) may be any form, as long as the reaction proceeds safely. Examples of such forms, as long as the reaction proceeds safely, include solids and liquids, as well as aqueous solutions of any concentration and solutions of solvents other than water (e.g., organic solvents). 【0278】 For example, when using hydroxylamine (free), any form of hydroxylamine is acceptable, as long as the reaction proceeds safely. Considering safety and economic efficiency, preferred forms of hydroxylamine (free) include aqueous solutions with a concentration of 10% or more and less than 70%, preferably aqueous solutions with a concentration of 45% or more and less than 55%. 【0279】 The amount of oximizing agent used in step (ii) may be any amount as long as the reaction proceeds. From the viewpoint of yield, suppression of by-products, and economic efficiency, in one embodiment, the amount is 0.9 to 1.5 equivalents, preferably 0.9 to 1.3 equivalents, when converted to hydroxylamine (NH2OH), per mole of compound (3) or compound (4). In another embodiment, the amount is 1.0 to 1.5 equivalents, preferably 1.0 to 1.3 equivalents, when converted to hydroxylamine (NH2OH), per mole of compound (3) or compound (4). However, the amount used can be appropriately adjusted by those skilled in the art. The meaning of the term "converted to hydroxylamine (NH2OH)" is as follows: For example, 1 mole of NH2OH·HCl is converted to 1 mole of NH2OH. Another example is that 1 mole of (NH2OH)2·H2SO4 is converted to 2 moles of NH2OH. Another example is that 1 mole of acetone oxime is equivalent to 1 mole of NH2OH. 【0280】 When using hydroxylamine salts (e.g., hydroxylamine hydrochloride, hydroxylamine sulfate, etc.), the reaction in step (ii) is preferably carried out using a neutralizing agent. The neutralizing agent is a base that neutralizes the hydroxylamine salt and liberates free hydroxylamine. Examples of neutralizing agents include, but are not limited to, alkali metal hydroxides (e.g., lithium hydroxide, sodium hydroxide, potassium hydroxide, etc.), alkaline earth metal hydroxides (e.g., magnesium hydroxide, calcium hydroxide, barium hydroxide, etc.), alkali metal carbonates (e.g., lithium carbonate, sodium carbonate, potassium carbonate, etc.), alkaline earth metal carbonates (e.g., magnesium carbonate, calcium carbonate, barium carbonate, etc.), alkali metal bicarbonates (e.g., lithium bicarbonate, sodium bicarbonate, potassium bicarbonate, etc.), alkali metal carboxylates (e.g., lithium acetate, sodium acetate, potassium acetate, etc.), amines (e.g., triethylamine, tributylamine, diisopropylethylamine, 1,8-diazabicyclo[5.4.0]-7-undeca-7-ene (DBU), pyridine, etc.), and ammonia (e.g., 25-30% aqueous ammonia, ammonia gas, preferably 25-30% aqueous ammonia). Preferred examples of neutralizing agents include sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, ammonia, more preferably sodium hydroxide, sodium carbonate, sodium bicarbonate, ammonia, and even more preferably sodium hydroxide. Examples of sodium hydroxide include, but are not limited to, sodium hydroxide beads, 48% aqueous sodium hydroxide solution, 25% aqueous sodium hydroxide solution, 10% aqueous sodium hydroxide solution, preferably 48% aqueous sodium hydroxide solution, 25% aqueous sodium hydroxide solution, and more preferably 48% aqueous sodium hydroxide solution. The neutralizing agent may be used alone or in any combination of two or more in any proportion. The form of the neutralizing agent may be any form as long as the reaction proceeds. Examples of such forms include solid, liquid, and gas of the neutralizing agent alone, as well as aqueous solutions of any concentration and solutions of solvents other than water (e.g., organic solvents). The form of the neutralizing agent can be appropriately selected by those skilled in the art. 【0281】 The amount of neutralizing agent used in step (ii) can be any amount as long as the reaction proceeds. From the viewpoint of yield, suppression of by-products, and economic efficiency, the amount is 0.5 to 3.0 moles, preferably 0.5 to 1.5 moles, more preferably 0.8 to 1.5 moles, and even more preferably 1.0 to 1.3 moles per mole of compound (3) or compound (4). 【0282】 (Solvent in step (ii)) From the viewpoint of smooth reaction progress and safety, it is preferable to carry out the reaction in step (ii) in the presence of a solvent. Any solvent may be used as long as the reaction in step (ii) proceeds and safety is ensured. Examples of solvents include water, alcohols (e.g., methanol, ethanol, 2-propanol, butanol, tert-butanol (tert-butanol is also called tert-butyl alcohol)), ethers (e.g., tetrahydrofuran (THF), 1,4-dioxane, diisopropyl ether, dibutyl ether, di-tert-butyl ether, cyclopentyl methyl ether (CPME), methyl-tert-butyl ether, 1,2-dimethoxyethane (DME), nitriles (e.g., (C2-C4) alkanenitriles (specifically, acetonitrile, etc.)), carboxylic acid esters (e.g., (C1-C6) alkyl(C2-C4) carboxylates (specifically, methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, vinegar, etc.) This includes, but is not limited to, butyl acids and their isomers, pentyl acetate and its isomers, etc., aromatic hydrocarbon derivatives (e.g., benzene, toluene, xylene, chlorobenzene, dichlorobenzene, nitrobenzene, etc.), halogenated aliphatic hydrocarbons (e.g., (C1-C3) dichloroalkanes (specifically, for example, dichloromethane, chloroform, 1,2-dichloroethane (EDC), etc.)), aliphatic hydrocarbons (e.g., hexane, heptane, octane, cyclohexane, ethylcyclohexane, etc.) and any combination thereof in any proportion. However, from the viewpoint of safety when using hydroxylamine, the reaction in step (ii) is preferably carried out in the presence of water. In any case, the solvent may separate into a single layer or two layers as long as the reaction proceeds. 【0283】 From the viewpoint of reactivity, yield, safety, and economic efficiency, preferred examples of the solvent in step (ii) include water, alcohols, ethers, nitriles, carboxylic acid esters, aromatic hydrocarbon derivatives, halogenated aliphatic hydrocarbons, and any combination thereof in any proportion; more preferably, water, nitriles, carboxylic acid esters, aromatic hydrocarbon derivatives, halogenated aliphatic hydrocarbons, and any combination thereof in any proportion; even more preferably, water, nitriles (preferably (C2-C4) alkanenitriles), carboxylic acid esters (preferably (C1-C6) alkyl(C2-C4) carboxylates), halogenated aliphatic hydrocarbons (preferably (C1-C3) dichloroalkanes), and any combination thereof in any proportion. However, the presence of water is preferred in all cases. Therefore, for example, any combination of water and nitriles (preferably (C2-C4) alkanenitriles) is preferred. Other examples include combinations of any proportion of water and carboxylic acid esters (preferably (C1-C6) alkyl(C2-C4) carboxylates). Further examples include combinations of any proportion of water and halogenated aliphatic hydrocarbons (preferably (C1-C3) dichloroalkanes). Preferred specific examples of the solvent in step (ii) include water, methanol, ethanol, 2-propanol, tert-butanol, acetonitrile, methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate and its isomers, tetrahydrofuran (THF), toluene, xylene, chlorobenzene, dichlorobenzene, dichloromethane, and any combination thereof in any proportion; more preferably, water, acetonitrile, methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate and its isomers, toluene, xylene, chlorobenzene, dichlorobenzene, dichloromethane, and any combination thereof in any proportion; even more preferably, water, acetonitrile, methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate and its isomers, dichloromethane, and any combination thereof in any proportion. However, the presence of water is preferred in all cases. Therefore, for example, any combination of water and acetonitrile in any proportion is preferred. Other examples include combinations of any proportion of water and butyl acetate and its isomers, and more preferably combinations of any proportion of water and butyl acetate. Further examples include combinations of water and dichloromethane in any proportion. In either case, the solvent may separate into a single layer or two layers, as long as the reaction proceeds. 【0284】 Water derived from an aqueous solution of hydroxylamine can be understood as a solvent. When a neutralizing agent is used together with a hydroxylamine salt (e.g., hydroxylamine hydrochloride, hydroxylamine sulfate, etc.), water derived from the aqueous solution of the neutralizing agent (e.g., a 48% sodium hydroxide aqueous solution) can also be understood as a solvent. Water produced by neutralization can also be understood as a solvent. 【0285】 The amount of solvent used in step (ii) may be any amount, as long as the reaction system can be sufficiently stirred. From the viewpoint of yield, suppression of by-products, and economic efficiency, the amount of solvent used is 0 to 10 L, preferably 0.02 to 5 L, more preferably 0.02 to 1 L, and even more preferably 0.1 to 1 L, per mole of compound (3) or compound (4). However, the amount used can be appropriately adjusted by those skilled in the art. When using a combination of two or more solvents, the ratio of the two or more solvents may be any ratio, as long as the reaction proceeds. The ratio can be appropriately adjusted by those skilled in the art. The solvent may separate into a single layer or two layers as long as the reaction proceeds. 【0286】 (Reaction temperature in process (ii)) The reaction temperature in step (ii) is not particularly limited. From the viewpoint of yield, suppression of by-products, and economic efficiency, examples include -30°C to 160°C, preferably -10°C to 80°C, more preferably 0°C to 80°C, even more preferably 10°C to 50°C, and even more preferably room temperature (10°C to 35°C). However, the reaction temperature can be appropriately adjusted by those skilled in the art. 【0287】 (Reaction time for process (ii)) The reaction time in step (ii) is not particularly limited. From the viewpoint of yield, suppression of by-products, and economic efficiency, it is 0.5 to 48 hours, preferably 0.5 to 24 hours, and more preferably 0.5 to 12 hours. However, the reaction time can be appropriately adjusted by those skilled in the art. 【0288】 (Product of step (ii); compound of formula (5) or compound of formula (6)) The product of step (ii) is a compound of formula (5) or formula (6) that corresponds to the compound of formula (3) or formula (4) used as a raw material.Specific examples include, but are not limited to, the following: 3-methyl-2-butenal oxime, 3-hydroxy-3-methylbutanal oxime (also called 3-hydroxy-3-methylbutane-1-al oxime), 3-methoxy-3-methylbutanal oxime, 3-ethoxy-3-methylbutanal oxime, 3-methyl-3-propoxybutanal oxime, 3-isopropoxy-3-methylbutanal oxime, 3-butoxy-3-methylbutanal oxime, 3-isobutoxy-3-methylbutanal oxime, 3-(sec-butanal oxime) Toxy)-3-methylbutanal oxime, 3-methyl-3-phenoxybutanal oxime, 3-(benzyloxy)-3-methylbutanal oxime, 3-hydroxy-3-methylpentanal oxime, 3-ethyl-3-hydroxypentanal oxime, 3-hydroxy-3,4-dimethylpentanal oxime, 3-hydroxy-3,4,4-trimethylpentanal oxime, 4-chloro-3-hydroxy-3-methylbutanal oxime, 4,4,4-trifluoro-3-hydroxy-3-methylbutanal oxime, 2-(1 2-(hydroxycyclopropyl)acetaldoxime oxime, 2-(1-hydroxycyclobutyl)acetaldoxime, 2-(1-hydroxycyclopentyl)acetaldoxime, 2-(1-hydroxycyclohexyl)acetaldoxime, 3-hydroxy-3-methylheptanal oxime, 3-hydroxy-3,7-dimethyl-6-octenal oxime, 3-hydroxy-3,7-dimethyloctanal oxime, 3-(9H-fluorene-9-ylidene)-3-hydroxypropanal oxime, 3-hydroxy-3,3-diph Phenyl-2-propanal oxime, 3-hydroxy-3,3-bis(4-methylphenyl)propanal oxime, 3-hydroxy-3,3-bis(4-methoxyphenyl)propanal oxime, 3-hydroxy-3,3-bis(4-chlorophenyl)propanal oxime, 3-hydroxy-3-phenylbutanal oxime, 3-hydroxy-3-(4-methylphenyl)butanal oxime, 3-hydroxy-3-(4-methoxyphenyl)butanal oxime, 3-hydroxy-3-(4-chlorophenyl)butanal oxime, etc.From the viewpoint of the usefulness of the product, preferred specific examples of the compound of formula (5) are 3-hydroxy-3-methylbutanal oxime and 3-methoxy-3-methylbutanal oxime, more preferably 3-methoxy-3-methylbutanal oxime. A preferred specific example of formula (6) is 3-methyl-2-butenal oxime. 【0289】 The compound of formula (5) or the compound of formula (6) obtained in step (ii) can be used as a raw material in step (iii). The compound of formula (5) or the compound of formula (6) obtained in step (ii) may be isolated and used in the next step, further purified and used in the next step, or used in the next step without isolation. However, it is more efficient to use it in the next step without isolation. 【0290】 (Step (iii)) Let's explain process (iii). All descriptions in step (iii) below apply to steps (iii-a) and (iii-b), unless otherwise specified. 【0291】 The reaction in step (iii) is a cyclization reaction. Step (iii) is also called the cyclization step. Step (iii) is a step in which the compound of formula (5) or the compound of formula (6) is reacted in the presence of a catalyst to produce the compound of formula (7). 【0292】 [ka] 【0293】 (In the formula, R 1 , R 2 and R 3 (This is as defined above.) 【0294】 (Raw materials for step (iii); compound of formula (5) or compound of formula (6)) As a raw material for step (iii), the compound of formula (5) or the compound of formula (6) is used. The compound of formula (5) or the compound of formula (6) is a known compound, or can be produced from a known compound in accordance with a known method. In addition, the compound of formula (5) or the compound of formula (6) can be produced by the method of step (ii) described above. Specific examples and preferred specific examples of the compound of formula (5) or the compound of formula (6) are as described above. 【0295】 (Catalyst for process (iii)) The catalyst in step (iii) can be any catalyst, as long as the reaction proceeds. Preferably, an acid catalyst can be used, or an acid catalyst and a base catalyst can be used. (Acid catalyst in step (iii)) In one embodiment of the present invention, the compound of formula (7) is produced in the presence of an acid catalyst. Any acid catalyst may be used as long as the reaction proceeds. In addition, any of the following forms may be used as long as the reaction proceeds, and are within the scope of the present invention: A free acid may be used as the acid catalyst. The acid catalyst may also be used in the form of a salt. If the acid catalyst is a salt, it may be a monosalt or a double salt. The acid catalyst may be used in an anhydrous form. The acid catalyst may be used in a hydrate form. The acid catalyst may be used in a dimer or other form. 【0296】 Examples of acid catalysts for step (iii) include, but are not limited to, the following: 【0297】 a) Mineral acids Mineral acids can be used as the acid catalyst in step (iii). Examples of mineral acids include hydrochloric acid, sulfuric acid, nitric acid, and phosphoric acid. 【0298】 b) Carboxylic acids As the acid catalyst in step (iii), carboxylic acids, their salts and anhydrides can be used. Therefore, the carboxylic acid may be used as the free acid or as its salt. In addition, the carboxylic acid may be used as its anhydride. Specific examples of carboxylic acids include acetic acid, trifluoroacetic acid (TFA), trichloroacetic acid, dichloroacetic acid, maleic acid, citric acid, benzoic acid, phthalic acid. Specific examples of preferred carboxylic acids include trifluoroacetic acid, trichloroacetic acid, dichloroacetic acid, maleic acid. Specific examples of carboxylates include ammonium trifluoroacetate (CF3COO - NH4 + )), N-methylanilinium trifluoroacetate (CF3COO - C6H5N + (CH3)H2). Specific examples of carboxylic acid anhydrides include trifluoroacetic anhydride, maleic anhydride, phthalic anhydride. Specific examples of preferred carboxylic acid anhydrides include maleic anhydride. 【0299】 c) Sulfonic acids As the acid catalyst in step (iii), sulfonic acids, their salts and anhydrides can be used. Therefore, the sulfonic acid may be used as the free acid or as its salt. In addition, the sulfonic acid may be used as its anhydride. Examples of sulfonic acids include methanesulfonic acid, trifluoromethanesulfonic acid (TfOH), benzenesulfonic acid, p-toluenesulfonic acid (including p-toluenesulfonic acid monohydrate (TsOH·H2O)), 10-camphorsulfonic acid. Examples of sulfonates include pyridinium p-toluenesulfonate (PPTS). Examples of sulfonic acid anhydrides include methanesulfonic anhydride, trifluoromethanesulfonic anhydride. 【0300】 From the viewpoints of yield, economic efficiency, etc., in one aspect, preferred examples of the acid catalyst are as follows, but are not limited thereto. One or more (preferably 1 to 3, more preferably 1 or 2, still more preferably 1) acids selected from the group consisting of mineral acids, carboxylic acids, sulfonic acids and phosphoric acids are preferred. 【0301】 As the base catalyst, amines are preferred. 【0302】 The amines are represented by the following formula: 【0303】 R 6 R 7 R 8 N 【0304】 (In the formula, R 6 , R 7 and R 8 are each independently a hydrogen atom, an optionally substituted (C1-C6) alkyl; an optionally substituted (C3-C6) cycloalkyl; an optionally substituted (C2-C6) alkenyl; an optionally substituted (C2-C6) alkynyl; or an optionally substituted aryl; or alternatively, any two of R 6 , R 7 and R 8 combine with the nitrogen atom to which they are attached to form a 4- to 12-membered heterocyclic ring, where the formed ring may be optionally substituted. Here, at least one of R 6 , R 7 and R 8 is not a hydrogen atom) may be a primary amine, secondary amine, tertiary amine, or heterocyclic amine. 【0305】 Specific examples of primary amines include, but are not limited to, methylamine, ethylamine, propylamine, butylamine, aniline, etc. Specific examples of secondary amines include, but are not limited to, diethylamine, dipropylamine, diisopropylamine, N-methylaniline (PhNHMe; may be abbreviated as N-MeAniline in this specification), N-ethylaniline, piperidine, morpholine, etc. 【0306】 Specific examples of tertiary amines include, but are not limited to, triethylamine, tripropylamine, tributylamine, diisopropylethylamine, 1,4-diazabicyclo[2.2.2]octane (DABCO), N,N-dimethylaniline, and N,N-diethylaniline. 【0307】 Specific examples of heterocyclic amines include, but are not limited to, pyridine, 4-(dimethylamino)-pyridine, 4-pyrrolidinopyridine, 2,6-lutidine, quinoline, isoquinoline, 1,8-diazabicyclo[5.4.0]-7-undeca-7-ene (DBU), and 1,5-diazabicyclo[4.3.0]nona-5-ene (DBN). 【0308】 4-(dimethylamino)-pyridine, 4-pyrrolidinopyridine, 1,8-diazabicyclo[5.4.0]-7-undeca-7-ene (DBU), and 1,5-diazabicyclo[4.3.0]nona-5-ene (DBN) also belong to the tertiary amine class. 【0309】 Examples of amines also include imidazolinones. Specific examples of imidazolinones include (2S,5S)-2-tert-butyl-3-methyl-5-benzyl-4-imidazolinone and its diastereomers and other optical isomers, as well as their analogs. However, since imidazolinones are expensive, it is industrially preferable not to use them. 【0310】 From the viewpoint of yield, economic efficiency, etc., preferred examples of bases in acid-base catalysts include secondary amines or heterocyclic amines. Preferred specific examples of bases in acid-base catalysts include N-methylaniline or pyridine. 【0311】 From the viewpoint of yield, suppression of by-products, and economic efficiency, the amount of acid catalyst used can be exemplified in the range of 0.01 to 1.0 moles, preferably 0.01 to 0.60 moles, more preferably 0.02 to 0.50 moles, or 0.05 to 0.40 moles, per mole of compound (5) or compound (6). From the viewpoint of yield, suppression of by-products, and economic efficiency, the amount of base catalyst used can be exemplified in the range of 0 to 1.0 moles, per mole of compound (5) or compound (6). When a base catalyst is used, the amount of base catalyst used can be exemplified in the range of 0.01 to 1.0 moles, preferably 0.01 to 0.60 moles, more preferably 0.02 to 0.50 moles, or 0.05 to 0.40 moles. When a base catalyst is used, the ratio of base catalyst to acid-base catalyst may be 1:1 or not. 【0312】 (Solvent in step (iii)) The reaction in step (iii) can be carried out in the presence or absence of a solvent. If a solvent is used in the reaction in step (iii), any solvent may be used as long as the reaction in step (iii) proceeds. If a solvent is used, examples of solvents include water, alcohols (e.g., methanol, ethanol, 2-propanol, butanol, tert-butanol (tert-butanol is also called tert-butyl alcohol)), ethers (e.g., tetrahydrofuran (THF), 1,4-dioxane, diisopropyl ether, dibutyl ether, di-tert-butyl ether, cyclopentyl methyl ether (CPME), methyl-tert-butyl ether, 1,2-dimethoxyethane (DME), nitriles (e.g., (C2-C4) alkanenitriles (specifically, acetonitrile, etc.)), carboxylic acid esters (e.g., (C1-C6) alkyl( This includes, but is not limited to, C2-C4 carboxylates (specifically, methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate and its isomers, pentyl acetate and its isomers, etc.), aromatic hydrocarbon derivatives (e.g., benzene, toluene, xylene, chlorobenzene, dichlorobenzene, nitrobenzene, etc.), halogenated aliphatic hydrocarbons (e.g., (C1-C3) dichloroalkanes, specifically, dichloromethane, chloroform, 1,2-dichloroethane (EDC), etc.), aliphatic hydrocarbons (e.g., hexane, heptane, octane, cyclohexane, ethylcyclohexane, etc.) and any combination thereof in any proportion. In any case, the solvent may separate into a single layer or two layers as long as the reaction proceeds. 【0313】 From the viewpoint of reactivity, yield, safety, and economic efficiency, preferred examples of the solvent in step (ii) include water, alcohols, ethers, nitriles, carboxylic acid esters, aromatic hydrocarbon derivatives, halogenated aliphatic hydrocarbons, and any combination thereof in any proportion; more preferably, water, nitriles, carboxylic acid esters, aromatic hydrocarbon derivatives, halogenated aliphatic hydrocarbons, and any combination thereof in any proportion; even more preferably, water, nitriles (preferably (C2-C4) alkanenitriles), carboxylic acid esters (preferably (C1-C6) alkyl(C2-C4) carboxylates), halogenated aliphatic hydrocarbons (preferably (C1-C3) dichloroalkanes), and any combination thereof in any proportion. Water may or may not be included. Therefore, for example, any combination of water and nitriles (preferably (C2-C4) alkanenitriles) is preferred. Other examples include combinations of any proportion of water and carboxylic acid esters (preferably (C1-C6) alkyl(C2-C4) carboxylates). Further examples include combinations of any proportion of water and halogenated aliphatic hydrocarbons (preferably (C1-C3) dichloroalkanes). Preferred specific examples of the solvent in step (iii) include water, methanol, ethanol, 2-propanol, tert-butanol, acetonitrile, methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate and its isomers, tetrahydrofuran (THF), toluene, xylene, chlorobenzene, dichlorobenzene, dichloromethane, and any combination thereof in any proportion; more preferably, water, acetonitrile, methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate and its isomers, toluene, xylene, chlorobenzene, dichlorobenzene, dichloromethane, and any combination thereof in any proportion; even more preferably, water, acetonitrile, methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate and its isomers, dichloromethane, and any combination thereof in any proportion. Water may or may not be included. Therefore, for example, any combination of water and acetonitrile in any proportion, or acetonitrile alone, is preferred. Other examples include any proportion of water and butyl acetate and its isomers, or butyl acetate and its isomers are preferred, with any proportion of water and butyl acetate or butyl acetate being more preferred. Further examples include any combination of water and dichloromethane in any proportion, or dichloromethane alone is preferred. In either case, the solvent may separate into a single layer or two layers, as long as the reaction proceeds. 【0314】 In this specification, the absence of a solvent is also referred to as solvent-free. 【0315】 When using a solvent in step (iii), any amount may be used, as long as the reaction system can be sufficiently stirred. From the viewpoint of yield, suppression of by-products, and economic efficiency, the amount of solvent used is 0 to 10 L, preferably 0.1 to 5 L, per mole of compound (5) or compound (6). When using a combination of two or more solvents, the ratio of the two or more solvents may be any ratio as long as the reaction proceeds. The solvent may be a single layer or separated into two layers as long as the reaction proceeds. 【0316】 In a manner in which steps (ii) and (iii) are carried out without isolating the compound of formula (5) or the compound of formula (6), the amount of solvent etc. in step (iii) can be set by ratio with the compound of formula (3) or the compound of formula (4). For example, the amount of solvent used in step (iii) is 0 to 10 L, preferably 0.1 to 5 L, per mole of the compound of formula (3) or the compound of formula (4). 【0317】 (Reaction temperature in step (iii)) The reaction temperature in step (iii) is not particularly limited. From the viewpoint of yield, suppression of by-products, and economic efficiency, it is -30°C to 160°C, preferably -10°C to 120°C, and more preferably 0 to 100°C. 【0318】 (Reaction time for step (iii)) The reaction time in step (iii) is not particularly limited. From the viewpoint of yield, suppression of by-products, and economic efficiency, it is 0.5 hours to 72 hours, preferably 1 hour to 60 hours, and more preferably 1 hour to 48 hours. 【0319】 (Product of step (iii); compound of formula (7)) The product of step (iii) is a compound of formula (7) equivalent to the compound of formula (5) or the compound of formula (6) used as a starting material. Specific examples include, but are not limited to, the following: 5,5-dimethyl-4,5-dihydroisoxazole, 5-ethyl-5-methyl-4,5-dihydroisoxazole, 5,5-diethyl-4,5-dihydroisoxazole, 5-isopropyl-5-methyl-4,5-dihydroisoxazole, 5-(tert-butyl)-5-methyl-4,5-dihydroisoxazole, 5-(chloromethyl)-5-methyl-4,5-dihydroisoxazole 5-methyl-5-(trifluoromethyl)-4,5-dihydroisoxazole, 5-cyclopropyl-5-methyl-4,5-dihydroisoxazole, 5-cyclobutyl-5-methyl-4,5-dihydroisoxazole, 5-cyclopentyl-5-methyl-4,5-dihydroisoxazole, 5-cyclohexyl-5-methyl-4,5-dihydroisoxazole, 5-butyl-5-methyl-4,5-dihydroisoxazole, 5-methyl- 5-(4-methylpenta-3-en-1-yl)-4,5-dihydroisoxazole, 5-methyl-5-(4-methylpentyl)-4,5-dihydroisoxazole, 4'H-spiro[fluorene-9,5'-isoxazole], 5,5-diphenyl-4,5-dihydroisoxazole, 5,5-bis(4-methylphenyl)-4,5-dihydroisoxazole, 5,5-bis(4-methoxyphenyl)-4,5-dihydroisoxazole, 5, Examples include 5-bis(4-chlorophenyl)-4,5-dihydroisoxazole, 5-methyl-5-phenyl-4,5-dihydroisoxazole, 5-ethyl-5-phenyl-4,5-dihydroisoxazole, 5-(4-methylphenyl)-5-methyl-4,5-dihydroisoxazole, 5-(4-methoxyphenyl)-5-methyl-4,5-dihydroisoxazole, and 5-(4-chlorophenyl)-5-methyl-4,5-dihydroisoxazole. From the viewpoint of the usefulness of the product, a preferred specific example of the compound of formula (7) is 5,5-dimethyl-4,5-dihydroisoxazole. 【0320】 (Embodiment of the reaction) The following description of the "Reaction Embodiments" applies to steps (i), (ia), and (ib), unless otherwise applicable. This reaction can be carried out in a batch manner using a reaction vessel, or in a flow reaction using a continuous reactor. A continuous reactor is a reactor that allows for the continuous supply of raw materials and the simultaneous progress of the reaction. One example of a continuous reactor is a flow reactor. A flow reactor is a reactor that can continuously supply raw materials and carry out the reaction continuously. Flow reactors are broadly classified into tubular flow reactors (including tube-type flow reactors) and tank-type flow reactors, both of which can carry out the reaction continuously. The flow reactor of the present invention may be provided with temperature control means for controlling the temperature of the flow reactor, for example, a temperature control unit for heating or cooling may be provided. The temperature control unit may be any appropriate type, and examples of temperature control units include baths and jackets. The style of the bath and jacket may be any appropriate style. Furthermore, there are no particular restrictions on the material of the flow reactor, as long as it is not affected by the raw materials and solvents. Examples include metals (e.g., titanium, nickel, stainless steel, Hastelloy C), resins (e.g., fluororesin), glass, and porcelain (e.g., ceramics). 【0321】 The continuous reaction of the present invention does not preclude implementation in a tank-type flow reactor. However, a preferred flow reactor is, for example, a tubular flow reactor. The tubular flow reactor of the present invention only needs to be capable of continuously flowing a liquid or gas-liquid mixture, and the cross-sectional shape of the tube may be circular, square, polygonal, elliptical, or any combination of these shapes. Furthermore, there are no particular restrictions on the material of the tube as long as it is not affected by the raw materials and solvents, and examples include metals (e.g., titanium, nickel, stainless steel, Hastelloy C), resins (e.g., fluororesin), glass, porcelain (e.g., ceramics), etc., but metal with excellent pressure resistance is preferred. The tubular flow reactor of the present invention may also be provided with temperature control means for controlling the temperature, for example, a temperature control unit for heating or cooling may be provided. The temperature control unit may be any appropriate type, and examples of temperature control units include baths and jackets. The style of the bath and jacket may be any appropriate style. Such flow-type reactors can include, for example, spiral-type, shell-and-tube-type, and plate heat exchange-type reactors. 【0322】 There are no particular restrictions on the arrangement of the tubes in the tubular flow reactor of the present invention; for example, they may be arranged in a straight line, a curved line, or a coil. A preferred arrangement is, for example, a tubular reactor in which the tubes are arranged in a coil. In addition, there may be one tube, or two or more tubes may be bundled together regularly or irregularly at appropriate intervals. For convenience, this specification will be based on a tubular flow reactor having one tube, but if it is desired to increase production efficiency, a tubular flow reactor in which two or more tubes are bundled together regularly or irregularly at appropriate intervals may be used as described herein. Furthermore, the tubular flow reactor of the present invention may optionally include a mixer. The mixer is not particularly limited as long as it has the function of continuously mixing two or more fluids, such as gas and liquid or liquid and liquid. Examples include Y-shaped mixers, T-shaped mixers, pipeline-type mixers (line mixers including static mixers, etc.). A line mixer including a static mixer, etc., may also be a tubular flow reactor. 【0323】 (Batch reaction) The following description of "batch reactions" applies to steps (i), (ia), and (ib). When employing a batch process, predetermined amounts of a metal catalyst, nitroxyl radical, nitric acid, alcohol compound (1) or alcohol compound (2), and solvent are added to the reactor (further amounts may be added if necessary), and the reaction mixture is stirred in the presence of oxygen at a predetermined temperature and for a predetermined time. The reaction temperature is not particularly limited. However, from the viewpoint of yield, suppression of by-products, and economic efficiency, it is 0°C to 100°C, preferably 10°C to 80°C, more preferably 30°C to 70°C, and even more preferably 40°C to 60°C. The reaction time is not particularly limited. However, from the viewpoint of yield, suppression of by-products, and economic efficiency, it is preferably 0.1 to 48 hours, more preferably 0.1 to 24 hours, and more preferably 1 to 12 hours. 【0324】 (Commercial reaction) The following description of the "flow-through reaction" applies to steps (i), (ia), and (ib). In addition, it may apply to all steps unless otherwise specified. When a flow-through reaction is adopted, a predetermined amount of mixture (which may be further added if necessary) of the metal catalyst, nitroxyl radical, alcohol compound (1) or alcohol compound (2), and solvent is passed through a tubular reactor, and oxygen is passed through another tube to carry out the reaction. In this case, it is preferable to use a tubular reactor equipped with a heating device and to pass the mixture through a reaction tube heated to a predetermined temperature. The reaction temperature is not particularly limited. However, from the viewpoint of yield, suppression of by-products, and economic efficiency, it is 0°C to 120°C, preferably 40°C to 100°C. 【0325】 The equivalent diameter of the tube in the tubular reactor of the present invention is not particularly limited as long as it is large enough for a liquid or gas-liquid mixture to flow continuously. However, since the chemical reaction of the present invention may involve a reaction with gas, and also from the viewpoint of production efficiency, it is preferable that the equivalent diameter be 0.5 mm or larger. Examples of preferred equivalent diameters include 0.5 mm to 50 mm, preferably 0.5 mm to 30 mm. In this invention, "equivalent diameter (De)" is a value defined by the following formula. De = 4·Af / Wp (In the formula, Af represents the cross-sectional area of ​​the channel, and Wp represents the length of the wetted edge.) For example, the equivalent diameter of a circular tube with radius r is: De = 4·πr 2 / 2πr = 2r 【0326】 The length of the tube in the tubular flow reactor of the present invention is not particularly limited, as long as it is within a range in which the raw material compounds can be heated and reacted sufficiently. For example, it is in the range of 1 m or more, preferably 1 m to 100 m, and more preferably 5 m to 80 m. In order to carry out the method of the present invention efficiently, it is necessary to react at a predetermined temperature and / or for sufficient reaction time, so a length of 5 m or more is generally preferred, but it is not limited to this. 【0327】 The flow velocity in the flow reactor of the present invention, preferably a tubular flow reactor, depends on the equivalent diameter of the tube, but for example, its lower limit is usually 0.1 m / min or more, preferably 1.0 m / min or more. In addition, for example, its upper limit is usually 4.0 m / min or less, preferably 3.0 m / min or less. The pressure inside the tubular flow reactor is, for example, 0.1 MPa to 10 MPa, preferably 0.1 MPa to 5 MPa, more preferably 0.1 MPa to 1 MPa, but is not limited to these ranges. 【0328】 (The solvent of the present invention) In addition to the above, in yet another embodiment, it is preferable that all steps of the reaction be carried out in the presence of an organic solvent. Furthermore, it is efficient and preferable that all steps of the reaction be carried out in the presence of the same organic solvent. In yet another embodiment, the same organic solvent is preferably a carboxylic acid ester, and more preferably a (C1-C6) alkyl(C2-C4) carboxylate. The same organic solvent is more preferably selected from the group consisting of methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate and its isomers, and pentyl acetate and its isomers. The same organic solvent is more preferably butyl acetate and its isomers, and particularly preferably butyl acetate. 【0329】 The present invention will be described in more detail below with reference to examples, but the present invention is not limited in any way by these examples. 【0330】 In this specification, the following equipment and conditions were used for the analysis of the examples and comparative examples. 【0331】 (GC analysis: Gas chromatography analysis) The following equipment and conditions, or equivalent or similar analytical methods, were used. Equipment: GC-2014 (manufactured by Shimadzu Corporation) Column: DB-1 (30m x 0.25mmφ x 0.25μm) Heating conditions: 60°C (5 minutes) → 15°C / min → 280°C (0 minutes) Injection temperature: 280℃ Detection temperature: 280℃ Detection method: FID Column flow rate: 2 mL / min 【0332】 Gas chromatography (GC) analysis methods; for GC analysis methods, refer to the following literature as needed. Reference (a): The Chemical Society of Japan (ed.), "New Experimental Chemistry Course 9: Analytical Chemistry II," pp. 60-86 (1977), published by Shingo Iizumi, Maruzen Co., Ltd. (For example, regarding stationary phase liquids usable in columns, see page 66.) Reference (b): The Chemical Society of Japan (ed.), "Experimental Chemistry Course 20-1 Analytical Chemistry," 5th edition, pp. 121-129 (2007), published by Seishiro Murata, Maruzen Co., Ltd. (For example, regarding the specific use of hollow capillary separation columns, see pp. 124-125.) 【0333】 (Flow-through reactor) Reaction tube; GL Sciences 3004-28082 SUS-316 stainless steel tubing 1 / 16 (in) * 1.0 (mm) * 10 (m) (used in Example 11) or EYELA PTFE TUBE 1 / 16 (in) * 1.0 (mm) * 10 (m) (Used in Examples 55 and 56) Heating device: Fine oil bath FWB-240 or block heater 【0334】 In this specification, room temperature is defined as between 10°C and 35°C. [Examples] 【0335】 Example 1 Production of 3-methoxy-3-methylbutanal oxime 【0336】 [ka] 【0337】 In a 50 mL round-bottom flask, acetonitrile (7.9 g, 1.0 L / mol), iron(III) chloride (49 mg, 0.30 mmol, 3.0 mol%), 69% nitric acid (27 mg, 0.30 mmol, 3.0 mol%), acetic acid (601 mg, 10.0 mmol, 100 mol%), N-methylimidazole (25 mg, 0.30 mmol, 3.0 mol%), 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl (69 mg, 0.40 mmol, 4.0 mol%), and 3-methoxy-3-methylbutanol (1.18 g, 10.0 mmol, 100 mol%) were added, and the mixture was stirred at 60°C under an oxygen atmosphere and allowed to react for 6.5 hours. GC analysis (area percentage) was performed on the reaction mixture. The results of the analysis were as follows: 3-Methoxy-3-methylbutanal (target product (3-a)): 98%, 3-Methoxy-3-methylbutanoic acid (by-product (9-a)): Not Detected (ND). After cooling to 0°C, a 50 w% hydroxylamine aqueous solution (726 mg, 11.0 mmol, 110 mol%) was added dropwise while stirring. Analysis of the reaction mixture using the GC internal standard method yielded 3-methoxy-3-methylbutanal oxime (target product (5-a)) in 96% yield. 【0338】 Example 2 Production of 3-methoxy-3-methylbutanal oxime 【0339】 The reaction equation is the same as in Example 1. 【0340】 In a 50 mL round-bottom flask, acetonitrile (7.9 g, 1.0 L / mol), iron(III) bromide (89 mg, 0.30 mmol, 3.0 mol%), 69% nitric acid (27 mg, 0.30 mmol, 3.0 mol%), acetic acid (601 mg, 10.0 mmol, 100 mol%), N-methylimidazole (25 mg, 0.30 mmol, 3.0 mol%), 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl (69 mg, 0.40 mmol, 4.0 mol%), and 3-methoxy-3-methylbutanol (1.18 g, 10.0 mmol, 100 mol%) were added, and the mixture was stirred at 60°C under an oxygen atmosphere and allowed to react for 6.5 hours. GC analysis (area percentage) was performed on the reaction mixture. The results of the analysis were as follows: 3-Methoxy-3-methylbutanal (target product (3-a)): 93%, 3-Methoxy-3-methylbutanoic acid (by-product (9-a)): 2%. After cooling to 0°C, a 50 w% hydroxylamine aqueous solution (726 mg, 11.0 mmol, 110 mol%) was added dropwise while stirring. Analysis of the reaction mixture using the GC internal standard method yielded 3-methoxy-3-methylbutanal oxime (target product (5-a)) in 88% yield. 【0341】 Example 3 Production of 3-methoxy-3-methylbutanal oxime 【0342】 The reaction equation is the same as in Example 1. 【0343】 In a 50 mL round-bottom flask, acetonitrile (7.9 g, 1.0 L / mol), iron(III) nitrate nonahydrate (121 mg, 0.30 mmol, 3.0 mol%), acetic acid (601 mg, 10.0 mmol, 100 mol%), N-methylimidazole (25 mg, 0.30 mmol, 3.0 mol%), 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl (69 mg, 0.40 mmol, 4.0 mol%), and 3-methoxy-3-methylbutanol (1.18 g, 10.0 mmol, 100 mol%) were added, and the mixture was stirred at 60°C under an oxygen atmosphere and allowed to react for 6.5 hours. GC analysis (area percentage) was performed on the reaction mixture. The results of the analysis were as follows: 3-Methoxy-3-methylbutanal (target product (3-a)): 91%, 3-Methoxy-3-methylbutanoic acid (by-product (9-a)): ND. After cooling to 0°C, a 50 w% hydroxylamine aqueous solution (726 mg, 11.0 mmol, 110 mol%) was added dropwise while stirring. Analysis of the reaction mixture using the GC internal standard method yielded 3-methoxy-3-methylbutanal oxime (target product (5-a)) in 85% yield. 【0344】 Example 4 Production of 3-methoxy-3-methylbutanal oxime 【0345】 The reaction equation is the same as in Example 1. 【0346】 In a 50 mL round-bottom flask, ethyl acetate (9.0 g, 1.0 L / mol), iron(III) chloride (49 mg, 0.30 mmol, 3.0 mol%), 69% nitric acid (27 mg, 0.30 mmol, 3.0 mol%), acetic acid (601 mg, 10.0 mmol, 100 mol%), N-methylimidazole (25 mg, 0.30 mmol, 3.0 mol%), 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl (69 mg, 0.40 mmol, 4.0 mol%), and 3-methoxy-3-methylbutanol (1.18 g, 10.0 mmol, 100 mol%) were added, and the mixture was stirred at 60°C under an oxygen atmosphere and allowed to react for 6.5 hours. GC analysis (area percentage) was performed on the reaction mixture. The results of the analysis were as follows: 3-Methoxy-3-methylbutanal (target product (3-a)): 94%, 3-Methoxy-3-methylbutanoic acid (by-product (9-a)): ND. After cooling to 0°C, a 50 w% hydroxylamine aqueous solution (726 mg, 11.0 mmol, 110 mol%) was added dropwise while stirring. Analysis of the reaction mixture using the GC internal standard method yielded 3-methoxy-3-methylbutanal oxime (target product (5-a)) in 85% yield. 【0347】 Example 5 Production of 3-methoxy-3-methylbutanal oxime 【0348】 The reaction equation is the same as in Example 1. 【0349】 In a 50 mL round-bottom flask, acetonitrile (7.9 g, 1.0 L / mol), iron(III) chloride (49 mg, 0.30 mmol, 3.0 mol%), 69% nitric acid (27 mg, 0.30 mmol, 3.0 mol%), propionic acid (741 mg, 10.0 mmol, 100 mol%), N-methylimidazole (25 mg, 0.30 mmol, 3.0 mol%), 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl (69 mg, 0.40 mmol, 4.0 mol%), and 3-methoxy-3-methylbutanol (1.18 g, 10.0 mmol, 100 mol%) were added, and the mixture was stirred at 60°C under an oxygen atmosphere and allowed to react for 6.5 hours. GC analysis (area percentage) was performed on the reaction mixture. The results of the analysis were as follows: 3-Methoxy-3-methylbutanal (target product (3-a)): 97%, 3-Methoxy-3-methylbutanoic acid (by-product (9-a)): ND. After cooling to 0°C, a 50 w% hydroxylamine aqueous solution (726 mg, 11.0 mmol, 110 mol%) was added dropwise while stirring. Analysis of the reaction mixture using the GC internal standard method yielded 3-methoxy-3-methylbutanal oxime (target product (5-a)) in 92% yield. 【0350】 Example 6 Production of 3-methoxy-3-methylbutanal oxime 【0351】 The reaction equation is the same as in Example 1. 【0352】 In a 50 mL round-bottom flask, acetonitrile (7.9 g, 1.0 L / mol), iron(III) chloride (49 mg, 0.30 mmol, 3.0 mol%), 69% nitric acid (27 mg, 0.30 mmol, 3.0 mol%), benzoic acid (1221 mg, 10.0 mmol, 100 mol%), N-methylimidazole (25 mg, 0.30 mmol, 3.0 mol%), 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl (69 mg, 0.40 mmol, 4.0 mol%), and 3-methoxy-3-methylbutanol (1.18 g, 10.0 mmol, 100 mol%) were added, and the mixture was stirred at 60°C under an oxygen atmosphere and allowed to react for 6.5 hours. GC analysis (area percentage) was performed on the reaction mixture. The results of the analysis were as follows: 3-Methoxy-3-methylbutanal (target product (3-a)): 95%, 3-Methoxy-3-methylbutanoic acid (by-product (9-a)): 3%. After cooling to 0°C, a 50 w% hydroxylamine aqueous solution (726 mg, 11.0 mmol, 110 mol%) was added dropwise while stirring. Analysis of the reaction mixture using the GC internal standard method yielded 3-methoxy-3-methylbutanal oxime (target product (5-a)) in 83% yield. 【0353】 Example 7 Production of 3-methoxy-3-methylbutanal oxime 【0354】 The reaction equation is the same as in Example 1. 【0355】 In a 50 mL round-bottom flask, acetonitrile (7.9 g, 1.0 L / mol), iron(III) chloride (49 mg, 0.30 mmol, 3.0 mol%), 69% nitric acid (27 mg, 0.30 mmol, 3.0 mol%), acetic acid (601 mg, 10.0 mmol, 100 mol%), N-methylpyrazole (25 mg, 0.30 mmol, 3.0 mol%), 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl (69 mg, 0.40 mmol, 4.0 mol%), and 3-methoxy-3-methylbutanol (1.18 g, 10.0 mmol, 100 mol%) were added, and the mixture was stirred at 60°C under an oxygen atmosphere and allowed to react for 6.5 hours. GC analysis (area percentage) was performed on the reaction mixture. The results of the analysis were as follows: 3-Methoxy-3-methylbutanal (target product (3-a)): 84%, 3-Methoxy-3-methylbutanoic acid (by-product (9-a)): 5%. After cooling to 0°C, a 50 w% hydroxylamine aqueous solution (726 mg, 11.0 mmol, 110 mol%) was added dropwise while stirring. Analysis of the reaction mixture using the GC internal standard method yielded 3-methoxy-3-methylbutanal oxime (target product (5-a)) in 75% yield. 【0356】 Example 8 Production of 3-methoxy-3-methylbutanal 【0357】 [ka] 【0358】 In a 50 mL round-bottom flask, acetonitrile (7.9 g, 1.0 L / mol), iron(III) chloride (49 mg, 0.30 mmol, 3.0 mol%), 69% nitric acid (27 mg, 0.30 mmol, 3.0 mol%), acetic acid (601 mg, 10.0 mmol, 100 mol%), N,N-dimethylaminopyridine (37 mg, 0.30 mmol, 3.0 mol%), 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl (69 mg, 0.40 mmol, 4.0 mol%), and 3-methoxy-3-methylbutanol (1.18 g, 10.0 mmol, 100 mol%) were added, and the mixture was stirred at 60°C under an oxygen atmosphere and reacted for 6.5 hours. GC analysis (area percentage) was performed on the reaction mixture. The results of the analysis were as follows: 3-Methoxy-3-methylbutanal (target product (3-a)): 91%, 3-Methoxy-3-methylbutanoic acid (by-product (9-a)): ND. 【0359】 Example 9 Production of 3-methoxy-3-methylbutanal 【0360】 The reaction equation is the same as in Example 8. 【0361】 In a 50 mL round-bottom flask, acetonitrile (7.9 g, 1.0 L / mol), iron(III) chloride (49 mg, 0.30 mmol, 3.0 mol%), 69% nitric acid (27 mg, 0.30 mmol, 3.0 mol%), acetic acid (601 mg, 10.0 mmol, 100 mol%), pyridine (24 mg, 0.30 mmol, 3.0 mol%), 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl (69 mg, 0.40 mmol, 4.0 mol%), and 3-methoxy-3-methylbutanol (1.18 g, 10.0 mmol, 100 mol%) were added, and the mixture was stirred at 60°C under an oxygen atmosphere and allowed to react for 6.5 hours. GC analysis (area percentage) was performed on the reaction mixture. The results of the analysis were as follows: 3-Methoxy-3-methylbutanal (target product (3-a)): 95%, 3-Methoxy-3-methylbutanoic acid (by-product (9-a)): ND. 【0362】 Example 10 Production of 3-methoxy-3-methylbutanal oxime 【0363】 The reaction equation is the same as in Example 1. 【0364】 In a 50 mL round-bottom flask, acetonitrile (7.9 g, 1.0 L / mol), copper(II) nitrate trihydrate (72 mg, 0.30 mmol, 3.0 mol%), 69% nitric acid (27 mg, 0.30 mmol, 3.0 mol%), acetic acid (601 mg, 10.0 mmol, 100 mol%), N-methylimidazole (25 mg, 0.30 mmol, 3.0 mol%), 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl (69 mg, 0.40 mmol, 4.0 mol%), and 3-methoxy-3-methylbutanol (1.18 g, 10.0 mmol, 100 mol%) were added, and the mixture was stirred at 60°C under an oxygen atmosphere and allowed to react for 6.5 hours. GC analysis (area percentage) was performed on the reaction mixture. The results of the analysis were as follows: 3-Methoxy-3-methylbutanal (target product (3-a)): 89%, 3-Methoxy-3-methylbutanoic acid (by-product (9-a)): ND. After cooling to 0°C, a 50 w% hydroxylamine aqueous solution (726 mg, 11.0 mmol, 110 mol%) was added dropwise while stirring. Analysis of the reaction mixture using the GC internal standard method yielded 3-methoxy-3-methylbutanal oxime (target product (5-a)) in 85% yield. 【0365】 Example 11 Production of 3-methoxy-3-methylbutanal 【0366】 The reaction equation is the same as in Example 8. 【0367】 In a 50 mL round-bottom flask, butyl acetate (10 mL), iron(III) chloride (32 mg, 0.20 mmol, 1.0 mol%), 69% nitric acid (110 mg, 1.20 mmol, 6.0 mol%), acetic acid (1.80 g, 30.0 mmol, 150 mol%), N-methylimidazole (49 mg, 0.60 mmol, 3.0 mol%), 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl (138 mg, 0.80 mmol, 4.0 mol%), and 3-methoxy-3-methylbutanol (2.36 g, 20.0 mmol, 100 mol%) were added to prepare a raw material solution under a nitrogen atmosphere. Subsequently, using a continuous flow reactor (reaction tube section: inner diameter 1 mm, length 40 m), the reaction tube was heated to 80°C, and then the raw material solution was supplied to the reaction tube at a flow rate of 1 mL / min and oxygen gas at 30 mL / min under a pressure of 0.6 MPa. The reaction mixture was collected from the outlet of a pressure regulating valve attached to the outlet of the reaction tube, and GC analysis (area percentage) of the reaction mixture was performed. The results of the analysis were as follows: 3-Methoxy-3-methylbutanal (target product (3-a)): 93%, 3-Methoxy-3-methylbutanoic acid (by-product (9-a)): ND. The apparatus used is shown in Figure 1. 【0368】 Example 12 Production of 3-methoxy-3-methylbutanal oxime 【0369】 The reaction equation is the same as in Example 1. 【0370】 In a 50 mL round-bottom flask, acetonitrile (7.9 g, 1.0 L / mol), iron(III) chloride (49 mg, 0.30 mmol, 3.0 mol%), 69% nitric acid (27 mg, 0.30 mmol, 3.0 mol%), acetic acid (601 mg, 10.0 mmol, 100 mol%), 2,2'-bipyridyl (47 mg, 0.30 mmol, 3.0 mol%), (25 mg, 0.30 mmol, 3.0 mol%), 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl (69 mg, 0.40 mmol, 4.0 mol%), and 3-methoxy-3-methylbutanol (1.18 g, 10.0 mmol, 100 mol%) were added, and the mixture was stirred at 60°C under an oxygen atmosphere and reacted for 6.5 hours. GC analysis (area percentage) was performed on the reaction mixture. The results of the analysis were as follows: 3-Methoxy-3-methylbutanal (target product (3-a)): 98%, 3-Methoxy-3-methylbutanoic acid (by-product (9-a)): 1%. After cooling to 0°C, a 50 w% hydroxylamine aqueous solution (726 mg, 11.0 mmol, 110 mol%) was added dropwise while stirring. Analysis of the reaction mixture using the GC internal standard method yielded 3-methoxy-3-methylbutanal oxime (target product (5-a)) in 84% yield. 【0371】 Example 13 Production of 3-methoxy-3-methylbutanal oxime 【0372】 The reaction equation is the same as in Example 1. 【0373】 In a 50 mL round-bottom flask, acetonitrile (7.9 g, 1.0 L / mol), iron(III) chloride (49 mg, 0.30 mmol, 3.0 mol%), 69% nitric acid (27 mg, 0.30 mmol, 3.0 mol%), acetic acid (601 mg, 10.0 mmol, 100 mol%), pyridine (24 mg, 0.30 mmol, 3.0 mol%), 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl (69 mg, 0.40 mmol, 4.0 mol%), and 3-methoxy-3-methylbutanol (1.18 g, 10.0 mmol, 100 mol%) were added, and the mixture was stirred at 60°C under an oxygen atmosphere and allowed to react for 6.5 hours. GC analysis (area percentage) was performed on the reaction mixture. The results of the analysis were as follows: 3-Methoxy-3-methylbutanal (target product (3-a)): 94%, 3-Methoxy-3-methylbutanoic acid (by-product (9-a)): ND. After cooling to 0°C, a 25% sodium hydroxide aqueous solution (1.60 g, 10.0 mmol, 100 mol%) was added dropwise while stirring, followed by the dropwise addition of a 50 w% hydroxylamine aqueous solution (726 mg, 11.0 mmol, 110 mol%). The mixture was analyzed by GC internal standard method, yielding 3-methoxy-3-methylbutanal oxime (target product (5-a)) in 94.5% yield. 【0374】 Example 14 Production of 3-methoxy-3-methylbutanal 【0375】 The reaction equation is the same as in Example 8. 【0376】 In a 200 mL round-bottom flask, add butyl acetate (97.9 mL, 0.75 L / mol), iron(III) chloride (420 mg, 2.6 mmol, 2.0 mol%), acetic acid (3.90 g, 65 mmol, 50 mol%), N-methylimidazole (320 mg, 3.9 mmol, 3.0 mol%), 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl (900 mg, 5.2 mmol, 4.0 mol%), and 3-methoxy-3-methylbutanol (15.36 g, 130 mmol, 100 mol%), and while stirring at 60°C, add 69% nitric acid (5.94 g, 65 mmol, 50 mol%) and acetic acid (7.81 g, 130 mmol, 100 mol%). The 100% mol% mixture was added dropwise over 5 hours while bubbling with 5% vol% oxygen-containing nitrogen at 20 mL / min. The reaction was then allowed to proceed at the same temperature for 4 hours. GC analysis (area percentage) was performed on the reaction mixture. The results of the analysis were as follows: 3-Methoxy-3-methylbutanal (target product (3-a)): 87%, 3-Methoxy-3-methylbutanoic acid (by-product (9-a)): 6%. 【0377】 Example 15 Manufacturing of 3-methyl-2-butenal 【0378】 [ka] 【0379】 In a 50 mL round-bottom flask, acetonitrile (7.9 g, 1.0 L / mol), iron(III) chloride (49 mg, 0.30 mmol, 3.0 mol%), 69% nitric acid (55 mg, 0.60 mmol, 6.0 mol%), acetic acid (601 mg, 10.0 mmol, 100 mol%), N-methylimidazole (25 mg, 0.30 mmol, 3.0 mol%), 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl (69 mg, 0.40 mmol, 4.0 mol%), and 3-methyl-2-butenol (8.61 g, 100 mmol, 100 mol%) were added and stirred at 60°C under an oxygen atmosphere for 1.5 hours. GC analysis (area percentage) of the reaction mixture was performed. The results of the analysis were as follows: 3-Methyl-2-butenal (target product (4-a)): 97%, 3-Methyl-2-butenic acid (by-product (10-a)): ND. 【0380】 Example 16 Manufacturing of 3-methyl-2-butenal 【0381】 The reaction equation is the same as in Example 15. 【0382】 In a 200 mL four-necked flask, butyl acetate (112.9 mL, 0.75 L / mol), iron(III) chloride (490 mg, 3.0 mmol, 2.0 mol%), 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl (1.03 g, 6.0 mmol, 4.0 mol%), and 3-methyl-2-butenol (12.92 g, 150 mmol, 100 mol%) were added. While stirring at 60°C, 69% nitric acid (6.85 g, 75 mmol, 50 mol%) was added dropwise over 5 hours, while bubbling with 5 vol% oxygen-containing nitrogen at 20 mL / min. The mixture was then allowed to react at the same temperature for 2 hours. GC analysis (area percentage) was performed on the reaction mixture. The results of the analysis were as follows: 3-Methyl-2-butenal (target product (4-a)): 94%, 3-Methyl-2-butenic acid (by-product (10-a)): ND. 【0383】 Example 17 Manufacturing of 3-methyl-2-butenal 【0384】 The reaction equation is the same as in Example 15. 【0385】 In a 20 mL test tube, acetonitrile (7.5 mL, 0.75 L / mol), iron(III) chloride (32 mg, 0.2 mmol, 2.0 mol%), 69% nitric acid (27 mg, 0.3 mmol, 3.0 mol%), acetic acid (901 mg, 15.0 mmol, 150 mol%), 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl (69 mg, 0.40 mmol, 4.0 mol%), and 3-methyl-2-butenol (861 mg, 10.0 mmol, 100 mol%) were added, and the mixture was stirred at 60°C under an oxygen atmosphere and allowed to react for 1 hour. GC analysis (area percentage) was performed on the reaction mixture. The results of the analysis were as follows: 3-Methyl-2-butenal (target product (4-a)): 98%, 3-Methyl-2-butenic acid (by-product (10-a)): ND. 【0386】 Examples 18-23 Manufacturing of 3-methyl-2-butenal 【0387】 The reaction equation is the same as in Example 15. 【0388】 The reaction and analysis were carried out in the same manner as in Example 17, except that the solvent and reaction time were changed as shown in Table 1. The results are shown in Table 1. In addition, the results of Example 17 are also summarized in Table 1. 【0389】 [Table 1] 【0390】 Example 24 Manufacturing of 3-methyl-2-butenal 【0391】 The reaction equation is the same as in Example 15. 【0392】 Butyl acetate (112.9 mL, 0.75 L / mol), iron(III) chloride (490 mg, 3.0 mmol, 2.0 mol%), 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl (1.03 g, 6.0 mmol, 4.0 mol%), and 3-methyl-2-butenol (12.92 g, 150 mmol, 100 mol%) were added to a 200 mL four-necked flask. 69% nitric acid (8.22 g, 90 mmol, 60 mol%) was added dropwise over 6 hours while stirring at 60°C, and the mixture was allowed to react at the same temperature for 2 hours. GC analysis (area percentage) was performed on the reaction mixture. The results of the analysis were as follows: 3-Methyl-2-butenal (target product (4-a)): 94%, 3-Methyl-2-butenic acid (by-product (10-a)): ND. 【0393】 Examples 25-29 Manufacturing of 3-methyl-2-butenal 【0394】 The reaction equation is the same as in Example 15. 【0395】 The reaction and analysis were carried out in the same manner as in Example 24, except that the amount of iron chloride used, the amount of 4-hydroxy-TEMPO used (equiv.), the amount of solvent, and the reaction temperature were changed as shown in Table 2. The results are shown in Table 2. In addition, the results of Example 24 are also summarized in Table 2. 【0396】 [Table 2] 【0397】 Example 30 Production of 5,5-dimethyl-4,5-dihydroisoxazole 【0398】 [ka] 【0399】 Butyl acetate (75 ml, 0.75 L / mol), iron(III) chloride (324 mg, 2 mmol, 2 mol%), 69% nitric acid (274 mg, 3 mmol, 3 mol%), acetic acid (9.01 g, 150 mmol, 150 mol%), N-methylimidazole (246 mg, 3 mmol, 3 mol%), 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (689 mg, 4 mmol, 4 mol%), and 3-methoxy-3-methylbutanol (11.8 g, 100 mmol, 100 mol%) were added to a 200 ml four-necked flask. The mixture was stirred at 60°C under an oxygen atmosphere and reacted for 4.5 hours. GC analysis (area percentage) was performed on the reaction mixture. The results of the analysis are as follows. 3-Methoxy-3-methylbutanal (target product (3-a)): 91%, 3-Methoxy-3-methylbutanoic acid (by-product (9-a)): 4%. After cooling to 0°C, an aqueous sodium hydroxide solution (25 wt%, 16 g, 100 mmol, 100 mol%) was added dropwise over 30 minutes while stirring, followed by the dropwise addition of a 2 M aqueous hydroxylamine sulfate solution (34.85 g, 104 mmol as hydroxylamine (NH2OH), 104 mol as hydroxylamine (NH2OH)) over 30 minutes. After the reaction was complete, the resulting mixture was filtered and then partitioned into an organic layer and an aqueous layer. The organic and aqueous layers were separated at 20-25°C. The aqueous layer was re-extracted with butyl acetate (10 ml, 0.1 L / mol), and all organic layers were combined. The yield of the obtained reaction mixture was determined by analyzing the reaction mixture using a calibration curve based on the GC internal standard method. 3-Methoxy-3-methylbutanal oxime (target product (5-a)): 83%. The mixture obtained in the above step (oxidation-oximation) (95.14 g, 84 mmol, 100 mol%) was transferred to a 200 ml four-necked flask, trifluoroacetic acid (2.87 g, 25 mmol, 30 mol%) was added, and the mixture was stirred at 60-65°C for 7 hours. After the reaction was complete, saturated brine (35 ml, 0.4 L / mol) was added, and the mixture was divided into an organic layer and an aqueous layer. The organic layer and aqueous layer were separated at 20-25°C. The organic layer was washed again with saturated brine (35 ml, 0.4 L / mol). The reaction mixture was analyzed using a calibration curve based on the GC internal standard method to determine the yield. 5,5-dimethyl-4,5-dihydroisoxazole (target product (7-a)): 83%. 【0400】 Example 31 Production of 5,5-dimethyl-4,5-dihydroisoxazole 【0401】 [ka] 【0402】 In a 200 mL four-necked flask, butyl acetate (112.9 ml, 0.75 L / mol), iron(III) chloride (490 mg, 3.0 mol, 2.0 mol%), acetic acid (4.50 g, 75 mmol, 50 mol%), 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (1.03 g, 6.0 mmol, 4.0 mol%), and 3-methyl-2-butenol (12.92 g, 150 mmol, 100 mol%) were added. While stirring at 60-65°C, a mixture of 69% nitric acid (6.85 g, 75 mmol, 50 mol%) and acetic acid (9.01 g, 150 mmol, 100 mol%) was added dropwise over 5 hours, while bubbling with 5 vol% oxygen-containing nitrogen at 20 ml / min. The mixture was then allowed to react at the same temperature for 1 hour. GC analysis (area percentage) was performed on the reaction mixture. The results of the analysis were as follows: 3-Methyl-2-butenal (target product (4-a)): 91%, 3-Methyl-2-butenic acid (by-product (10-a)): ND. After cooling to 0-5°C, a 25 wt% sodium hydroxide aqueous solution (24.0 g, 150 mol, 100 mol%) and a 2 M hydroxylamine sulfate aqueous solution (51.8 g, 156 mmol as hydroxylamine (NH2OH), 104 mol as hydroxylamine (NH2OH)) were added dropwise while stirring. The reaction mixture was analyzed by GC internal standard method to determine the yield. 3-Methyl-2-butenal oxime (target product (6-a)): 81%. The mixture obtained in the above process (oxidation-oxime formation) (129.65 g, 120 mmol, 100 mol%) was transferred to a 300 ml four-neck separable flask, 69% nitric acid (1.10 g, 12 mmol, 10 mol%) was added, and the mixture was stirred at 60-65°C for 18 hours. The reaction mixture was analyzed using a calibration curve based on the GC internal standard method to determine the yield. 5,5-dimethyl-4,5-dihydroisoxazole (target product (7-a)): 87%. 【0403】 Example 32 Production of 5,5-dimethyl-4,5-dihydroisoxazole 【0404】 The reaction equation is the same as in Example 31. 【0405】 In a 200 mL four-necked flask, butyl acetate (75.0 mL, 0.50 L / mol), iron(III) chloride (243 mg, 1.5 mmol, 1.0 mol%), 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl (1.03 g, 6.0 mmol, 4.0 mol%), and 3-methyl-2-butenol (12.92 g, 150 mmol, 100 mol%) were added. While stirring at 60°C, 69% nitric acid (8.90 g, 97.5 mmol, 65 mol%) was added dropwise over 6.5 hours, and the mixture was allowed to react at the same temperature for 0.5 hours. GC analysis (area percentage) was performed on the reaction mixture. The results of the analysis were as follows: 3-Methyl-2-butenal (target product): 94%, 3-Methyl-2-butenic acid (by-product): ND. After cooling to 0-5°C, a 35 wt% aqueous solution of hydroxylamine sulfate (36.1 g, 150 mmol as hydroxylamine (NH2OH), 100 mol as hydroxylamine (NH2OH)) was added dropwise over 0.5 hours while stirring. Subsequently, a 25 wt% aqueous solution of sodium hydroxide (24.0 g, 150 mmol, 100 mol) was added dropwise over 1 hour at the same temperature, and the reaction was continued for another 1 hour at the same temperature. The reaction rate was analyzed using the GC internal standard method to determine the yield. 3-Methyl-2-butenal oxime: 75%. The mixture obtained in the above process (77.81 g, 108.6 mmol, 100 mol%) was transferred to a 200 mL four-necked flask, 69% nitric acid (991 mg, 10.86 mmol, 10 mol%) was added, and the mixture was stirred at a temperature of 60-65°C for 18.5 hours. The reaction rate was analyzed using the GC internal standard method to determine the yield. 5,5-dimethyl-4,5-dihydroisoxazole: 91% 【0406】 Example 33 Preparation of 5,5-dimethyl-4,5-dihydroisoxazole 【0407】 [ka] 【0408】 3-methyl-2-butenal (15.0 g, 178 mmol, 100 mol%) was dissolved in dichloromethane (90 ml, 0.5 L / mol). 50% aqueous hydroxylamine solution (11.8 g, 178 mmol, 100 mol%) was added dropwise to bring the internal temperature to 30-40°C (exothermic reaction). After the addition was complete, the mixture was stirred at room temperature for 4 hours. After the reaction was complete, saline solution (10 ml) was added and the mixture was stirred. The resulting mixture was partitioned into an organic layer and an aqueous layer. The organic and aqueous layers were separated to obtain the organic layer. The obtained organic layer was dried over magnesium sulfate and concentrated under reduced pressure (400 Torr) at 40°C (bath temperature) until the amount of the organic layer reached 36 g to obtain crude 3-methyl-2-butenal oxime (yield: quantitative, containing approximately 14 ml of dichloromethane). To the mixture of 3-methyl-2-butenal oxime and dichloromethane obtained above, 22 ml of dichloromethane was added so that the total amount of dichloromethane in the reaction system was approximately 36 ml (0.2 L / mol). Trifluoroacetic acid (TFA, 2.03 g, specific gravity: 1.49, 1.36 ml, 17.8 mmol, 10 mol%) was then added, and the mixture was stirred at room temperature for 48 hours. GC analysis (area percentage) of the reaction mixture revealed that the main components of the reaction mixture, excluding solvents, were as follows: 5,5-dimethyl-4,5-dihydroisoxazole (target product (7-a)): 94%, 3-methyl-2-butenal oxime (intermediate (6-a)): 1%. Diethyl ether (40 ml) was added to the reaction mixture, and the resulting mixture was partitioned into an organic layer and an aqueous layer. The organic layer and aqueous layer were separated to obtain the organic layer. The organic layer was sequentially washed with aqueous sodium carbonate solution and saline solution, dried over magnesium sulfate, and concentrated under reduced pressure. The resulting crude product was purified by vacuum distillation to obtain 5,5-dimethyl-4,5-dihydroisoxazole (7-a, colorless oily substance, 13.7 g, purity: 99% (GC area percentage), 137 mmol, yield: 77% (2 steps), boiling point: 75~77°C / 50 Torr). 【0409】 Example 34 Preparation of 5,5-dimethyl-4,5-dihydroisoxazole 【0410】 The reaction equation is the same as in Example 33. 【0411】 3-methyl-2-butenal (10.0 g, 119 mmol, 100 mol%) was dissolved in dichloromethane (60 ml, 0.5 L / mol). 50% aqueous hydroxylamine solution (7.9 g, 119 mmol, 100 mol%) was added dropwise to bring the internal temperature to 30-40°C (exothermic reaction). After the addition was complete, the mixture was stirred at room temperature for 4 hours. After the reaction was complete, saline solution (10 ml) was added and the mixture was stirred. The resulting mixture was partitioned into an organic layer and an aqueous layer. The organic and aqueous layers were separated to obtain the organic layer. The obtained organic layer was dried over magnesium sulfate and concentrated under reduced pressure (400 Torr) at 40°C (bath temperature) until the amount of the organic layer reached 31 g to obtain crude 3-methyl-2-butenal oxime (yield: quantitative, containing approximately 14 ml of dichloromethane). To the mixture of 3-methyl-2-butenal oxime and dichloromethane obtained above, 10 ml of dichloromethane was added so that the total amount of dichloromethane in the reaction system was approximately 24 ml (0.2 L / mol). p-toluenesulfonic acid monohydrate (PTS·H2O, 2.3 g, 11.9 mmol, 10 mol%) was then added, and the mixture was stirred at room temperature for 60 hours. GC analysis (area percentage) of the reaction mixture revealed the following main components, excluding solvents, etc.: 5,5-dimethyl-4,5-dihydroisoxazole (target product (7-a)): 95%, 3-methyl-2-butenal oxime (intermediate (6-a)): 3%. Diethyl ether (30 ml) was added to the reaction mixture, and the resulting mixture was partitioned into an organic layer and an aqueous layer. The organic layer and aqueous layer were separated to obtain the organic layer. The organic layer was sequentially washed with aqueous sodium carbonate solution and saline solution, dried over magnesium sulfate, and concentrated under reduced pressure. The resulting crude product was purified by vacuum distillation to obtain 5,5-dimethyl-4,5-dihydroisoxazole (7-a, colorless oily substance, 8.3 g, purity: 99% (GC area percentage), 83 mmol, yield: 70%, boiling point: 75~77°C / 50 Torr). 【0412】 Example 35 Preparation of 5,5-dimethyl-4,5-dihydroisoxazole 【0413】 The reaction equation is the same as in Example 33. 【0414】 In a 25 ml round-bottom flask, hydroxylamine hydrochloride (8.91 g, 128 mmol, 110 mol%) was mixed with water (12 ml) and dichloromethane (12 ml, 0.1 L / mol). Then, under ice cooling and stirring, aqueous ammonia (7.80 g, 28% purity, 128 mmol, 110 mol%) was added. To keep the temperature below 30°C, 3-methyl-2-butenal (10.0 g, 98% purity (GC area%), 117 mmol, 100 mol%) was added, and the mixture was stirred at room temperature for 1 hour. The resulting mixture was partitioned into an organic layer and an aqueous layer. The organic layer and aqueous layer were separated. The aqueous layer was extracted with a small amount of dichloromethane. At this time, the pH of the aqueous layer was 6.6. The organic layers obtained above were combined in a 50 ml round-bottom flask (total dichloromethane used: 23 ml, total 0.2 L / mol). Maleic acid (1.35 g, 11.7 mmol, 10 mol%) was added, and the mixture was stirred at 30°C for 48 hours. GC analysis (area percentage) of the reaction mixture revealed that, excluding solvents, the components of the reaction mixture were as follows: 5,5-dimethyl-4,5-dihydroisoxazole (target product (7-a)): 96%. After the reaction was complete, saturated sodium bicarbonate aqueous solution (12 ml) was added and the mixture was stirred. The resulting mixture was partitioned into an organic layer and an aqueous layer. The organic layer and aqueous layer were separated. The aqueous layer was extracted with a small amount of dichloromethane, and the combined organic layers were concentrated under reduced pressure. The resulting crude product was purified by vacuum distillation to obtain 5,5-dimethyl-4,5-dihydroisoxazole (7-a, colorless oil, 9.5 g, yield: 82%, boiling point: 75~77°C / 50 Torr). 【0415】 Example 36 Preparation of 5,5-dimethyl-4,5-dihydroisoxazole 【0416】 The reaction equation is the same as in Example 33. 【0417】 In a 25 ml round-bottom flask, hydroxylamine sulfate (10.5 g, 128 mmol as hydroxylamine (NH2OH), 110 mol as hydroxylamine (NH2OH)) was mixed with water (5 ml) and dichloromethane (12 ml, 0.1 L / mol). Then, under ice cooling and stirring, 25% sodium hydroxide aqueous solution (approximately 20 g, 128 mmol, 110 mol) was added until the pH reached 6.9. 3-methyl-2-butenal (10.0 g, 98% purity (GC area%), 117 mmol, 100 mol) was added, keeping the temperature below 30°C, and the mixture was stirred at room temperature for 1 hour. The resulting mixture was partitioned into an organic layer and an aqueous layer. The organic layer and aqueous layer were separated. The aqueous layer was extracted with a small amount of dichloromethane. The organic layers obtained above were combined in a 50 ml round-bottom flask (total dichloromethane used: 23 ml, total 0.2 L / mol). 70% nitric acid (1.05 g, 11.7 mmol, 10 mol%) was added, and the mixture was stirred at 30°C for 48 hours. GC analysis (area percentage) of the reaction mixture revealed the following components, excluding solvents, etc.: 5,5-dimethyl-4,5-dihydroisoxazole (target product (7-a)): 84%. After the reaction was complete, saturated sodium bicarbonate aqueous solution (12 ml) was added and the mixture was stirred. The resulting mixture was partitioned into an organic layer and an aqueous layer. The organic layer and aqueous layer were separated. The aqueous layer was extracted with a small amount of dichloromethane, and the combined organic layers were concentrated under reduced pressure. The resulting crude product was purified by vacuum distillation to obtain 5,5-dimethyl-4,5-dihydroisoxazole (7-a, colorless oil, 9.2 g, yield: 80%, boiling point: 75~77°C / 50 Torr). 【0418】 Example 37 Preparation of 5,5-dimethyl-4,5-dihydroisoxazole 【0419】 The reaction equation is the same as in Example 33. 【0420】 In a 25 ml round-bottom flask, hydroxylamine sulfate (9.56 g, 117 mmol as hydroxylamine (NH2OH), 100 mol as hydroxylamine (NH2OH)) was mixed with water (12 ml) and dichloromethane (12 ml, 0.1 L / mol). Then, under ice cooling and stirring, aqueous ammonia (7.09 g, 28% purity, 117 mmol, 100 mol) was added. To keep the temperature below 30°C, 3-methyl-2-butenal (10.2 g, 98% purity (GC area%), 119 mmol, 102 mol) was added and the mixture was stirred at room temperature for 1 hour. The resulting mixture was partitioned into an organic layer and an aqueous layer. The organic layer and aqueous layer were separated. The aqueous layer was extracted with a small amount of dichloromethane. 【0421】 The organic layers obtained above were combined in a 50 ml round-bottom flask (total dichloromethane used: 23 ml, total 0.2 L / mol). Maleic acid (406 mg, 3.50 mmol, 3 mol%) and N-methylaniline (126 μl, specific gravity 0.99 (20°C), 125 mg, 1.17 mmol, 1 mol%) were added, and the mixture was stirred at 30°C for 48 hours. GC analysis (area percentage) of the reaction mixture revealed the following components excluding solvents, etc.: 5,5-dimethyl-4,5-dihydroisoxazole (target product (7-a)): 93%. After the reaction was complete, saturated sodium bicarbonate aqueous solution (12 ml) was added and the mixture was stirred. The resulting mixture was partitioned into an organic layer and an aqueous layer. The organic layer and aqueous layer were separated. The aqueous layer was extracted with a small amount of dichloromethane, and the combined organic layers were concentrated under reduced pressure. The resulting crude product was purified by vacuum distillation to obtain 5,5-dimethyl-4,5-dihydroisoxazole (7-a, colorless oil, 8.9 g, yield: 75%, boiling point: 75~77°C / 50 Torr). 【0422】 Example 38 Preparation of 5,5-dimethyl-4,5-dihydroisoxazole 【0423】 [ka] 【0424】 In a 50 ml round-bottom flask, planal (10.0 g, purity: 98% (GC area%), 116.5 mmol, 100 mol%) was dissolved in dichloromethane (11.7 ml, 0.1 L / mol), and then trifluoroacetic acid (0.89 ml, specific gravity: 1.49 (20°C)), 1.33 g, 11.7 mmol, 10 mol%) was added under ice cooling. Under ice cooling, hydroxylamine aqueous solution (7.55 g, purity: 52% (titrated with 1.0 M hydrochloric acid), 118.8 mmol, 102 mol%) was added, keeping the temperature below 30°C, and the mixture was stirred at 45°C for 20 hours (aging). GC analysis (area percentage) of the reaction mixture revealed the following components excluding the solvent: 5,5-dimethyl-4,5-dihydroisoxazole (target product (7-a)): 96%. After the reaction was complete, saturated sodium bicarbonate aqueous solution (12 ml) was added and the mixture was stirred. The resulting mixture was partitioned into an organic layer and an aqueous layer. The organic layer and aqueous layer were separated. The aqueous layer was extracted with a small amount of dichloromethane, and the combined organic layers were concentrated under reduced pressure. The resulting crude product was purified by vacuum distillation to obtain 5,5-dimethyl-4,5-dihydroisoxazole (7-a, colorless oil, 9.3 g, 93.8 mmol, yield: 81%, boiling point: 75~77°C / 50 Torr). 【0425】 Examples 39-44 Preparation of 5,5-dimethyl-4,5-dihydroisoxazole 【0426】 The reaction equation is the same as in Example 38. 【0427】 The reaction and analysis were carried out in the same manner as in Example 38, except that the amount of organic solvent, hydroxylamine used, catalyst, and stirring conditions (aging conditions) were changed as shown in Table 3. The results are shown in Table 3. In addition, the results of Example 38 are also summarized in Table 3. 【0428】 [Table 3] 【0429】 Example 45 Preparation of 5,5-dimethyl-4,5-dihydroisoxazole 【0430】 [ka] 【0431】 11.83 g of 3-a (8.46 mmol, 100 mol%) dichloromethane solution, 4.23 ml of water (0.5 L / mol), and hydroxylamine sulfate (0.69 g, 4.23 mmol as hydroxylamine (NH2OH), 100 mol%) were added to a 50 ml test tube. After adding 0.71 g of 48% sodium hydroxide aqueous solution (8.46 mmol, 100 mol%) dropwise at a temperature of 10-20°C, the mixture was stirred for 1 hour. The yield was determined from the calibration curve using the GC internal standard method, and the GC yield of 5-a was 85.6%. Trifluoroacetic acid (0.29 g, 2.53 mmol, 35 mol%) and N-methylaniline (0.09 g, 0.87 mmol, 12 mol%) were added, and the mixture was stirred at 50°C for 24 hours. GC analysis (area percentage) of the reaction mixture revealed that the target components, excluding solvents and other substances, were as follows: 5,5-dimethyl-4,5-dihydroisoxazole (target product (7-a)): 80%. 【0432】 After the reaction was complete, the resulting mixture was partitioned into an organic layer and an aqueous layer, and the two layers were separated. The yield was determined using a calibration curve based on the GC internal standard method. 5,5-dimethyl-4,5-dihydroisoxazole (target product (7-a)): 79% (calculated from 3-a). 【0433】 Examples 46-48 Preparation of 5,5-dimethyl-4,5-dihydroisoxazole 【0434】 The reaction equation is the same as in Example 45. 【0435】 The reaction and analysis were carried out in the same manner as in Example 45, except that the addition of the oximizing agent and neutralizing agent was changed. The results of Examples 45 to 48 are shown in Table 4. 【0436】 [Table 4] 【0437】 Example 49 Preparation of 5,5-dimethyl-4,5-dihydroisoxazole 【0438】 [ka] 【0439】 5-a (1.21g, 7.35 mmol, 100 mol%) and maleic acid (0.09g, 0.73 mmol, 10 mol%) were added to a 50 ml test tube and stirred at 50°C for 12 hours. GC analysis (area percentage) of the reaction mixture revealed that the target components, excluding solvents and other substances, were as follows: 5,5-dimethyl-4,5-dihydroisoxazole (target product (7-a)): 82%. 【0440】 After the reaction was complete, the yield of the resulting mixture was determined using a calibration curve based on the GC internal standard method. 5,5-dimethyl-4,5-dihydroisoxazole (target product (7-a)): 84%. 【0441】 The reaction equation is the same as in Example 33. 【0442】 Examples 50-54 【0443】 The reaction and analysis were carried out in the same manner as in Example 49, except that the acid catalyst, base catalyst, solvent, temperature, and reaction time were changed. The results of Examples 49 to 54 are shown in Table 5. 【0444】 [Table 5] 【0445】 Example 54 Preparation of 5,5-dimethyl-4,5-dihydroisoxazole 【0446】 [ka] 【0447】 In a 50 ml test tube, a solution of 3-a (11.83 g, 8.46 mmol, 100 mol%) dichloromethane, water (4.23 ml, 0.50 L / mol), acetone oxime (0.62 g, 8.45 mmol, 100 mol%), trifluoroacetic acid (0.27 g, 2.40 mmol, 28 mol%), and N-methylaniline (0.09 g, 0.83 mmol, 10 mol%) were added, and the mixture was stirred at 50°C for 24 hours. GC analysis (area percentage) of the reaction mixture revealed that the target components, excluding solvents and other substances, were as follows: 5,5-dimethyl-4,5-dihydroisoxazole (target product (7-a)): 86%. 【0448】 Example 55 Manufacturing of 3-methyl-2-butenal 【0449】 The reaction equation is the same as in Example 15. 【0450】 Under a nitrogen atmosphere, 3-methyl-2-butenol (11.45 g, 133 mmol, 100 mol%), iron(III) chloride (215 mg, 1.33 mmol, 1 mol%), and 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl (916 mg, 5.32 mmol, 4 mol%) were dissolved in 100 mL of butyl acetate to prepare the starting material solution. Then, using a continuous flow reactor (reaction tube: inner diameter 1 mm, length 10 m), the reaction was carried out as follows: The starting material solution was supplied to a Y-tube mixer at a flow rate of 0.97 mL / min, and a 69% nitric acid aqueous solution was supplied at a flow rate of 0.05 mL / min for mixing. The resulting mixture was then supplied to a reaction tube heated to 60°C for reaction. The reaction mixture was collected and subjected to GC analysis (area percentage). The results of the analysis were as follows: 3-Methyl-2-butenal (target product (4-a)): 83%, 3-Methyl-2-butenic acid (by-product (10-a)): ND. The yield was determined by analyzing the reaction reaction using a calibration curve based on the GC internal standard method. 3-Methyl-2-butenal (target product (4-a)): 75%. The apparatus used is shown in Figure 2. 【0451】 Example 56 Manufacturing of 3-methyl-2-butenal 【0452】 The reaction equation is the same as in Example 15. 【0453】 Under a nitrogen atmosphere, a solution was prepared by dissolving 3-methyl-2-butenol (11.45 g, 133 mmol, 100 mol%) and 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl (916 mg, 5.32 mmol, 4 mol%) in 50 mL of butyl acetate. Separately, under a nitrogen atmosphere, a solution was prepared by dissolving iron(III) chloride (215 mg, 1.33 mmol, 1 mol%) and 69% nitric acid aqueous solution (607 mg, 6.64 mmol, 5.0 mol%) in 50 mL of butyl acetate. Subsequently, the reaction was carried out using a continuous flow reactor (reaction tube section: inner diameter 1 mm, length 20 m) as follows: Under a pressure of 0.5 MPa, the two raw material solutions prepared above were each supplied to a Y-tube mixer at a flow rate of 0.05 mL / min and mixed. This mixture was then supplied to a reaction tube heated to 80°C, and simultaneously, oxygen gas was supplied at 3.15 mL / min. The reaction mixture was collected from the outlet of a pressure regulating valve attached to the outlet of the reaction tube, and GC analysis (area percentage) of the reaction mixture was performed. The results of the analysis were as follows: 3-Methyl-2-butenal (target product (4-a)): 96%. 3-Methyl-2-butenic acid (by-product (10-a)): ND. The apparatus used is shown in Figure 3. 【0454】 Reference example 1 Manufacturing of 5,5-dimethyl-4,5-dihydroisoxazole-3-thiocarboxamidine hydrochloride 【0455】 [ka] Butyl acetate (85 ml, 0.85 L / mol) was placed in a 300 ml four-necked flask, and the mixture obtained in Example 31 (123.75 g, 100 mmol, 100 mol%) was added dropwise over 1 hour while bubbling chlorine (7.81 g, 110 mmol, 110 mol%) at 0-5°C. The mixture was then stirred at the same temperature for 1 hour. The yield was determined by analyzing the reaction mixture using a calibration curve based on the GC internal standard method. 3-Chloro-5,5-dimethyl-4,5-dihydroisoxazole (target product (11)): 94.1%. After the reaction was complete, thiourea (7.88 g, 104 mmol, 110 mol%) was added to the resulting reaction mixture and stirred at 0-5°C for 23 hours. After the reaction was complete, water (28.3 ml, 0.3 L / mol) was added, and the resulting mixture was partitioned into an organic layer and an aqueous layer. The organic and aqueous layers were separated at 20-25°C. The organic layer was re-extracted with water (9.41 ml, 0.1 L / mol), and all the aqueous layers were combined. The yield was determined by analyzing the aqueous layer using a calibration curve based on the LC absolute calibration curve method. 5,5-dimethyl-4,5-dihydroisoxazole-3-thiocarboxamidine hydrochloride (target product (12)): 95%. 【0456】 Reference example 2 Confirmation of oxygen generation 【0457】 Butyl acetate (38.0 mL, 0.38 L / mol) and 69% nitric acid (9.13 g, 100 mmol, 100 mol%) were added to a 200 mL four-necked flask. While stirring at 60°C, iron(III) chloride (162 mg, 1.0 mmol, 1.0 mol%), 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl (345 mg, 2.0 mmol, 2.0 mol%), and 3-methyl-2-butenol (8.61 g, 100 mmol, 100 mol%) were added in order. The gas generated at the same temperature was then collected. Analysis of the obtained 2 liters of gas using a GASTEC gas sampling kit GV-100S revealed that it contained 7 volume% oxygen. This confirmed that oxygen is generated in the reaction of the present invention. Gas analysis method: Analysis was performed using a GASTEC gas sampler set GV-100S and a GASTEC oxygen gas detector tube No. 31B with a measurement range of 3-24 v%, according to the GASTEC No. 31B instruction manual. 【0458】 Comparative Example 1 Production of 3-hydroxy-3-methylbutanal 【0459】 [ka] 【0460】 In a 1 L round-bottom flask, 3-methyl-1,3-butanediol (1-a) (50.00 g, 480.08 mmol, 100 mol%) was dissolved in dichloromethane (240.05 ml, 0.5 L / mol), and then tetrabutylammonium bromide (1.55 g, 4.80 mmol, 1 mol%), 2,2,6,6-tetramethylpiperidine 1-oxyl (0.15 g, 0.96 mmol, 0.2 mol%), and phosphoric acid (5.54 g, 48.01 mmol, 10 mol%) were added. The mixture was cooled to 0-10°C, and sodium hypochlorite aqueous solution (12.63 wt%, 311.25 g, 528.08 mmol, 110 mol%) was added dropwise over 4 hours, followed by stirring for 1 hour. GC analysis (area percentage) of the reaction mixture revealed the following components, excluding the solvent: 3-Hydroxy-3-methylbutanal (target product (3-b)): 77%, 3-Hydroxy-3-methylbutanoic acid (by-product (9-b)): 5%, Ester compound A (by-product (13-a)): 4%, Ester compound B (by-product (13-b)): 10%. 【0461】 Comparative Example 2 Production of 3-methoxy-3-methylbutanal 【0462】 [ka] 【0463】 In a 500 mL four-necked flask, 3-methoxy-3-methylbutanol (20.00 g, 169.23 mmol, 100 mol%) was dissolved in dichloromethane (169.23 ml, 1.0 L / mol), and then tetrabutylammonium bromide (0.55 g, 1.69 mmol, 1 mol%), 2,2,6,6-tetramethylpiperidine 1-oxyl (0.026 g, 0.17 mmol, 0.1 mol%), and phosphoric acid (1.95 g, 16.92 mmol, 10 mol%) were added. At 0-10°C, sodium hypochlorite aqueous solution (13.95 wt%, 99.34 g, 186.16 mmol, 110 mol%) was added dropwise over 4 hours, and the mixture was stirred for 1 hour. GC analysis (area percentage) of the reaction mixture revealed that the target components, excluding solvents and other substances, were as follows: 3-Methoxy-3-methylbutanal (target product (3-a)): 91%, Ester compound A (by-product (13-a)): 7%. 【0464】 Comparative Example 3 Production of 3-methoxy-3-methylbutanal 【0465】 The reaction equation is the same as in Example 8. 【0466】 In a 50 mL round-bottom flask, acetonitrile (7.9 g, 1.0 L / mol), magnesium(II) nitrate hexahydrate (77 mg, 0.30 mmol, 3.0 mol%), acetic acid (601 mg, 10.0 mmol, 100 mol%), N-methylimidazole (25 mg, 0.30 mmol, 3.0 mol%), 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl (69 mg, 0.40 mmol, 4.0 mol%), and 3-methoxy-3-methylbutanol (1.18 g, 10.0 mmol, 100 mol%) were added, and the mixture was stirred at 60°C under an oxygen atmosphere and allowed to react for 6.5 hours. GC analysis (area percentage) was performed on the reaction mixture. The results of the analysis were as follows: 3-Methoxy-3-methylbutanal (target product (3-a)): ND. 【0467】 Comparative Example 4 Production of 3-methoxy-3-methylbutanal 【0468】 The reaction equation is the same as in Example 8. 【0469】 In a 50 mL round-bottom flask, acetonitrile (7.9 g, 1.0 L / mol), cobalt(II) nitrate hexahydrate (87 mg, 0.30 mmol, 3.0 mol%), acetic acid (601 mg, 10.0 mmol, 100 mol%), N-methylimidazole (25 mg, 0.30 mmol, 3.0 mol%), 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl (69 mg, 0.40 mmol, 4.0 mol%), and 3-methoxy-3-methylbutanol (1.18 g, 10.0 mmol, 100 mol%) were added, and the mixture was stirred at 60°C under an oxygen atmosphere and allowed to react for 6.5 hours. GC analysis (area percentage) was performed on the reaction mixture. The results of the analysis were as follows: 3-Methoxy-3-methylbutanal (target product (3-a)): ND. 【0470】 Comparative Example 5 Production of 3-methoxy-3-methylbutanal 【0471】 The reaction equation is the same as in Example 8. 【0472】 In a 50 mL round-bottom flask, acetonitrile (7.9 g, 1.0 L / mol), manganese(II) nitrate hexahydrate (86 mg, 0.30 mmol, 3.0 mol%), acetic acid (601 mg, 10.0 mmol, 100 mol%), N-methylimidazole (25 mg, 0.30 mmol, 3.0 mol%), 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl (69 mg, 0.40 mmol, 4.0 mol%), and 3-methoxy-3-methylbutanol (1.18 g, 10.0 mmol, 100 mol%) were added, and the mixture was stirred at 60°C under an oxygen atmosphere and reacted for 6.5 hours. GC analysis (area percentage) was performed on the reaction mixture. The results of the analysis were as follows: 3-Methoxy-3-methylbutanal (target product (3-a)): ND. 【0473】 Comparative Example 6 Production of 3-methoxy-3-methylbutanal 【0474】 The reaction equation is the same as in Example 8. 【0475】 In a 50 mL round-bottom flask, acetonitrile (7.9 g, 1.0 L / mol), nickel(II) nitrate hexahydrate (86 mg, 0.30 mmol, 3.0 mol%), acetic acid (601 mg, 10.0 mmol, 100 mol%), N-methylimidazole (25 mg, 0.30 mmol, 3.0 mol%), 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl (69 mg, 0.40 mmol, 4.0 mol%), and 3-methoxy-3-methylbutanol (1.18 g, 10.0 mmol, 100 mol%) were added, and the mixture was stirred at 60°C under an oxygen atmosphere and reacted for 6.5 hours. GC analysis (area percentage) was performed on the reaction mixture. The results of the analysis were as follows: 3-Methoxy-3-methylbutanal (target product (3-a)): ND. 【0476】 Comparative Example 7 Preparation of 3-methoxy-3-methylbutanal (proceded in the same manner as in Example 1, except that acetic acid was not used). 【0477】 The reaction equation is the same as in Example 8. 【0478】 In a 50 mL round-bottom flask, acetonitrile (7.9 g, 1.0 L / mol), iron(III) chloride (49 mg, 0.30 mmol, 3.0 mol%), 69% nitric acid (27 mg, 0.30 mmol, 3.0 mol%), N-methylimidazole (25 mg, 0.30 mmol, 3.0 mol%), 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl (69 mg, 0.40 mmol, 4.0 mol%), and 3-methoxy-3-methylbutanol (1.18 g, 10.0 mmol, 100 mol%) were added, and the mixture was stirred at 60°C under an oxygen atmosphere and allowed to react for 6.5 hours. GC analysis (area percentage) was performed on the reaction mixture. The results of the analysis were as follows: 3-Methoxy-3-methylbutanal (target product (3-a)): 24%, 3-Methoxy-3-methylbutanoic acid (by-product (9-a)): ND. 【0479】 Comparative Example 8 Preparation of 3-methoxy-3-methylbutanal (proceded in the same manner as in Example 1, except that water was used instead of acetic acid) 【0480】 The reaction equation is the same as in Example 8. 【0481】 In a 50 mL round-bottom flask, acetonitrile (7.9 g, 1.0 L / mol), iron(III) chloride (49 mg, 0.30 mmol, 3.0 mol%), 69% nitric acid (27 mg, 0.30 mmol, 3.0 mol%), water (18 mg, 10.0 mmol, 100 mol%), N-methylimidazole (25 mg, 0.30 mmol, 3.0 mol%), 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl (69 mg, 0.40 mmol, 4.0 mol%), and 3-methoxy-3-methylbutanol (1.18 g, 10.0 mmol, 100 mol%) were added, and the mixture was stirred at 60°C under an oxygen atmosphere and reacted for 6.5 hours. GC analysis (area percentage) was performed on the reaction mixture. The results of the analysis were as follows: 3-Methoxy-3-methylbutanal (target product (3-a)): 29%, 3-Methoxy-3-methylbutanoic acid (by-product (9-a)): ND. 【0482】 Comparative Example 9 Preparation of 3-methoxy-3-methylbutanal (proceded in the same manner as in Example 1, except that tert-butanol was used instead of acetic acid). 【0483】 The reaction equation is the same as in Example 8. 【0484】 In a 50 mL round-bottom flask, acetonitrile (7.9 g, 1.0 L / mol), iron(III) chloride (49 mg, 0.30 mmol, 3.0 mol%), 69% nitric acid (27 mg, 0.30 mmol, 3.0 mol%), tert-butanol (74 mg, 10.0 mmol, 100 mol%), N-methylimidazole (25 mg, 0.30 mmol, 3.0 mol%), 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl (69 mg, 0.40 mmol, 4.0 mol%), and 3-methoxy-3-methylbutanol (1-b) (1.18 g, 10.0 mmol, 100 mol%) were added, and the mixture was stirred at 60°C under an oxygen atmosphere and allowed to react for 6.5 hours. GC analysis (area percentage) was performed on the reaction mixture. The results of the analysis were as follows: 3-Methoxy-3-methylbutanal (target product (3-a)): 18%, 3-Methoxy-3-methylbutanoic acid (by-product (9-a)): ND. 【0485】 Comparative Example 10 Preparation of 3-methoxy-3-methylbutanal oxime (The reaction conditions of Example III in Prior Art Document 3, International Publication No. 2005 / 082825, were applied to the substrate of the present invention). 【0486】 The reaction equation is the same as in Example 1. 【0487】 In a 50 mL round-bottom flask, iron(III) nitrate nonahydrate (101 mg, 0.25 mmol, 0.5 mol%), 2,2'-bipyridyl (39 mg, 0.25 mmol, 0.5 mol%), 2,2,6,6-tetramethylpiperidine 1-oxyl (55 mg, 0.35 mmol, 0.7 mol%), and N-bromosuccinimide (53 mg, 0.30 mmol, 0.6 mol%) were dissolved in glacial acetic acid (5 mL). The reaction vessel was purged with oxygen five times, heated to 45°C with stirring, and 3-methoxy-3-methylbutanol (5.91 g, 50.0 mmol, 100 mol%) was added at the same temperature, and the reaction was allowed to proceed for 250 minutes. GC analysis (area percentage) was performed on the reaction mixture. The results of the analysis were as follows: 3-Methoxy-3-methylbutanal (target product (3-a)): 65.3%, 3-Methoxy-3-methylbutanoic acid (by-product (9-a)): ND. After cooling to 0°C, a 50 w% hydroxylamine aqueous solution (3.3 g, 55.0 mmol, 110 mol%) was added dropwise. Analysis of the reaction mixture using the GC internal standard method yielded 3-methoxy-3-methylbutanal oxime (target product (5-a)) in 63% yield. 【0488】 Comparative Example 11 Preparation of 3-methoxy-3-methylbutanal (The reaction conditions of Example 1 of Chinese Patent Application No. 101709026, prior art document 4, were applied to the substrate of this application.) 【0489】 The reaction equation is the same as in Example 8. 【0490】 In a 50 mL round-bottom flask, 3-methoxy-3-methylbutanol (5.91 g, 50.0 mmol, 100 mol%), iron(III) nitrate nonahydrate (101 mg, 0.3 mmol, 0.3 mol%), and 2,2,6,6-tetramethylpiperidine 1-oxyl (55 mg, 0.35 mmol, 0.7 mol%) were dissolved in dichloromethane (6.5 mL). The reaction vessel was purged with oxygen and the reaction was carried out at room temperature for 6 hours. GC analysis (area percentage) was performed on the reaction mixture. The results of the analysis were as follows: 3-Methoxy-3-methylbutanal (target product (3-a)): 3%. 【0491】 Comparative Example 12 Preparation of 3-methoxy-3-methylbutanal (The reaction conditions of Example 9 of Chinese Patent Application No. 101709026, prior art document 4, were applied to the substrate of this application.) 【0492】 The reaction equation is the same as in Example 8. 【0493】 In a 50 mL round-bottom flask, 3-methoxy-3-methylbutanol (5.91 g, 50.0 mmol, 100 mol%), iron(III) nitrate nonahydrate (101 mg, 0.3 mmol, 0.3 mol%), and 2,2,6,6-tetramethylpiperidine 1-oxyl (55 mg, 0.35 mmol, 0.7 mol%) were dissolved in acetonitrile (6.5 mL). The reaction vessel was purged with oxygen and the reaction was carried out at 50°C for 6 hours. GC analysis (area percentage) was performed on the reaction mixture. The results of the analysis were as follows: 3-Methoxy-3-methylbutanal (target product (3-a)): 35%. 【0494】 Comparative Example 13 Preparation of 3-methyl-2-butenal (The reaction and analysis were carried out in the same manner as in Example 24, except that 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl, which was used in Example 24, was not used.) 【0495】 The reaction equation is the same as in Example 15. 【0496】 In a 200 mL four-necked flask, butyl acetate (112.9 mL, 0.75 L / mol), iron(III) chloride (490 mg, 3.0 mmol, 2.0 mol%), and 3-methyl-2-butenol (12.92 g, 150 mmol, 100 mol%) were added. While stirring at 60°C, 69% nitric acid (6.85 g, 75 mmol, 50 mol%) was added dropwise over 5 hours, while bubbling with 5 vol% oxygen-containing nitrogen at 20 mL / min. The mixture was then allowed to react at the same temperature for 2 hours. GC analysis (area percentage) was performed on the reaction mixture. The results of the analysis were as follows: 3-Methyl-2-butenal (target product (4-a)): 8%, 3-Methyl-2-butenic acid (by-product (10-a)): ND. 【0497】 Comparative Example 14 Preparation of 3-methyl-2-butenal (The reaction and analysis were carried out in the same manner as in Example 24, except that iron(III) chloride used in Example 24 was not used.) 【0498】 The reaction equation is the same as in Example 15. 【0499】 In a 200 mL four-necked flask, butyl acetate (112.9 mL, 0.75 L / mol), 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl (1.03 g, 6.0 mmol, 4.0 mol%), and 3-methyl-2-butenol (12.92 g, 150 mmol, 100 mol%) were added. While stirring at 60°C, 69% nitric acid (6.85 g, 75 mmol, 50 mol%) was added dropwise over 5 hours, while bubbling with 5 vol% oxygen-containing nitrogen at 20 mL / min. The mixture was then allowed to react at the same temperature for 2 hours. GC analysis (area percentage) was performed on the reaction mixture. The results of the analysis were as follows: 3-Methyl-2-butenal (target product (4-a)): 63%, 3-Methyl-2-butenic acid (by-product (10-a)): ND. 【0500】 Comparative Example 15 Manufacturing of 3-methyl-2-butenal 【0501】 The reaction equation is the same as in Example 15. (The reaction and analysis were carried out in the same manner as in Example 24, except that the reaction temperature was changed to 20°C.) 【0502】 In a 200 mL four-necked flask, butyl acetate (112.9 mL, 0.75 L / mol), iron(III) chloride (490 mg, 3.0 mmol, 2.0 mol%), 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl (1.03 g, 6.0 mmol, 4.0 mol%), and 3-methyl-2-butenol (12.92 g, 150 mmol, 100 mol%) were added. While stirring at 20°C, 69% nitric acid (6.85 g, 75 mmol, 50 mol%) was added dropwise over 5 hours, while bubbling with 5 vol% oxygen-containing nitrogen at 20 mL / min. The mixture was then allowed to react at the same temperature for 2 hours. GC analysis (area percentage) was performed on the reaction mixture. The results of the analysis were as follows: 3-Methyl-2-butenal (target product (4-a)): 79%, 3-Methyl-2-butenic acid (by-product (10-a)): ND. [Industrial applicability] 【0503】 The present invention provides novel methods for producing compounds of formula (3), formula (4), and formula (7), which are useful as intermediates in the manufacture of pharmaceuticals and agrochemicals. The production method of the present invention is economical, environmentally friendly, and has high industrial value. Therefore, the present invention has high industrial applicability.

Claims

[Claim 1] A method for producing the compound of formula (7), comprising the following steps: Step (i) React the compound of formula (2) in the presence of a metal catalyst, nitric acid, oxygen, and a nitroxyl radical compound to obtain the compound of formula (4), where the metal catalyst is an iron catalyst or a copper catalyst: 【Chemistry 1】 (In the formula, R １ and R ２ Each of these is independently a substituted (C1-C6) alkyl group. Step (ii) The compound of formula (4) is reacted with an oximating agent to obtain the compound of formula (6): 【Chemistry 2】 (In the formula, R １ And R2 is as defined above. Step (iii) React the compound of formula (6) in the presence of an acid catalyst, or in the presence of both an acid catalyst and a base catalyst, to obtain the compound of formula (7): 【Transformation 3】 (In the formula, R １ And R2 is as defined above. [Claim 2] A manufacturing method according to claim 1, wherein the metal catalyst is iron(III) chloride. [Claim 3] A method for producing a product according to claim 1, wherein the nitroxyl radical compound is 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl. [Claim 4] The substituent of the compound described in claim 1 is R １ A method for producing a product in which R2 is methyl. [Claim 5] A method for producing a compound of formula (4), comprising reacting a compound of formula (2) in the presence of a metal catalyst, nitric acid, oxygen, and a nitroxyl radical compound to obtain a compound of formula (4), wherein the metal catalyst is an iron catalyst or a copper catalyst: 【Chemistry 4】 (In the formula, R １ and R ２ Each of these is independently a substituted (C1-C6) alkyl group. [Claim 6] A manufacturing method according to claim 5, wherein the metal catalyst is iron(III) chloride.

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