Process for producing thionoalkoxysilanes

Abstract

To provide a method for efficiently producing a thionoacyloxysilane.SOLUTION: A method for producing a thionoacyloxysilane includes a reaction step of reacting an alkoxysilane with a diacylsulfide.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to an efficient method for producing thionoacyloxysilanes.

Background Art

[0002] Thionoacyloxysilanes are functional chemicals used as reagents for precision synthesis such as pharmaceuticals, agricultural chemicals, and electronic materials, and their synthetic intermediates. As methods for producing thionoacyloxysilanes, for example, (A) a method of reacting bissilylsilazane with thiocarboxylic acid (Non-Patent Document 1), (B) a method of reacting chlorosilane with thiocarboxylic acid in the presence of a base (Non-Patent Document 1), (C) a method of reacting chlorosilane with potassium thiocarboxylate (Non-Patent Document 2), etc. are known.

Prior Art Documents

Non-Patent Documents

[0003]

Non-Patent Document 1

Non-Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, the method using bissilylsilazane (Method A) has problems such as the silazane compound of the raw material being easily hydrolyzed and requiring care in handling, and there being few types of commercially available compounds that are easily obtainable. Also, in the methods using chlorosilane (Methods B and C), since chlorosilane that generates corrosive hydrogen chloride by hydrolysis is used, there are problems such as the raw materials not being easily handled. Furthermore, in the methods using bissilylsilazane or chlorosilane (Methods A to C), a large amount of salt is generated in the reaction, so there are problems such as the process of removing the salt by filtration or other methods taking time and cost. For these reasons, an industrially more advantageous manufacturing method is required.

[0005] The present invention has been made in view of the above circumstances, and an object thereof is to provide a method for more efficiently producing thionoacyloxysilanes.

Means for Solving the Problems

[0006] As a result of intensive studies to solve the above problems, the present inventors have found that by reacting alkoxysilanes and diacyl sulfides, thionoacyloxysilanes are efficiently produced without generating a large amount of salt or the like, and have thus completed the present invention.

[0007] The production method of the present invention has the following characteristics. (1) The raw materials are easily obtainable, relatively easy to handle, and have high safety. (2) No salt is generated in this reaction system, and a large-scale salt separation step is not required. (3) When using an acidic solid catalyst, the catalyst can be easily separated by filtration, centrifugation, or the like. The production method of the present invention enables cost reduction and high efficiency of the production process, and is considered to have great advantages in terms of economy, environmental load, etc. compared with the prior art.

[0008] That is, this application provides the following invention. <1> A method for producing thionoacyloxysilanes, comprising a reaction step of reacting alkoxysilanes with diacyl sulfides. <2> The method for producing thionoacyloxysilanes according to <1>, wherein the reaction step is carried out in the presence of a catalyst. <3> The method for producing thionoacyloxysilanes according to <1> or <2>, wherein the alkoxysilanes are represented by the following general formula (I), the diacyl sulfides are represented by the following general formula (II), and the thionoacyloxysilanes are represented by the following general formula (III). R 1 p R 2 q R 3 r Si(OR 4 ) 4-(p+q+r) (I) (In the formula, p, q, and r are each independently an integer of 0 or more and 3 or less; p + q + r is an integer of 0 or more and 3 or less; R 1 , R 2 , and R 3 are each independently a hydrocarbon group having 1 to 24 carbon atoms or a hydrogen atom, and a part or all of the hydrogen atoms bonded to the carbon atoms of the hydrocarbon group may be substituted with a group that does not participate in the reaction; R 4 are each independently an alkyl group having 1 to 6 carbon atoms.) (R 5 CO)2S (II) (In the formula, R 5 is a hydrocarbon group having 1 to 24 carbon atoms, and a part or all of the hydrogen atoms bonded to the carbon atoms of the hydrocarbon group may be substituted with a group that does not participate in the reaction.) R 1 p R 2 q R 3 r Si(OR 4 ) 4-(p+q+r+s) [OC(=S)R 5 s (III) (In the formula, p, q, r, R 1 , R​2 , R 3 , R 4 , and R 5 are each synonymous with the above; s is an integer of 1 or more and 4 - (p + q + r) or less.) <4> The method for producing thionoacyloxysilanes according to any one of <1> to <3>, wherein the catalyst is an acidic catalyst. <5> The method for producing thionoacyloxysilanes according to <4>, wherein the acidic catalyst is an acidic compound selected from bis(perfluoroalkanesulfonyl)imide and metal salts thereof. <6> The method for producing thionoacyloxysilanes according to <4>, wherein the acidic catalyst is a solid acid catalyst selected from montmorillonite and zeolite.

Advantages of the Invention

[0009] According to the present invention, thionoacyloxysilanes can be produced more efficiently than by conventional methods.

Embodiments for Carrying Out the Invention

[0010] Hereinafter, the present invention will be described in detail. Unless otherwise specified, when a symbol in a certain formula in this specification is also used in other formulas, the same symbol indicates the same meaning. The method for producing thionoacyloxysilanes according to one embodiment of the present invention includes a reaction step of reacting alkoxysilanes with diacyl sulfides. The reaction step can be carried out in the presence of a catalyst for promoting the reaction.

[0011] In the present embodiment, the alkoxysilanes used as raw materials are, for example, represented by the following general formula (I) (hereinafter, the alkoxysilanes represented by the general formula (I) may be referred to as "alkoxysilane (I)"). R 1 p R 2 q R 3 rSi(OR 4 ) 4-(p+q+r) (I) In general formula (I), p, q, and r are each independently an integer of 0 or more and 3 or less; p + q + r is an integer of 0 or more and 3 or less. Further, R 1 , R 2 , and R 3 are each independently a hydrocarbon group having 1 to 24 carbon atoms or a hydrogen atom, and a part or all of the hydrogen atoms bonded to the carbon atoms of the hydrocarbon group may be substituted with a group that does not participate in the reaction. R 4 are each independently an alkyl group having 1 to 6 carbon atoms. In the present specification, "not participating in the reaction" means not directly participating as a reactant in the target reaction and not inhibiting the reaction.

[0012] R 1 , R 2 , and R 3 Examples of the hydrocarbon group represented by include an alkyl group, an aryl group, an aralkyl group, an alkenyl group, and the like. When the hydrocarbon group is an alkyl group, the number of carbon atoms of the alkyl group is preferably 1 to 20, more preferably 1 to 18, still more preferably 1 to 10, and particularly preferably 1 to 4. A part or all of the hydrogen atoms bonded to the carbon atoms of the alkyl group may be substituted with a group that does not participate in the reaction.

[0013] Examples of the group that does not participate in the reaction include an alkoxy group having 1 to 6 carbon atoms, an alkoxycarbonyl group having 1 to 6 carbon atoms, a dialkylamino group having 1 to 6 carbon atoms, a cyano group, a nitro group, a halogen atom, and the like. More specifically showing the alkoxy group, the alkoxycarbonyl group, the dialkylamino group, and the halogen atom, specific examples of the alkoxy group having 1 to 6 carbon atoms include a methoxy group, an ethoxy group, a hexyloxy group, etc.; specific examples of the alkoxycarbonyl group having 1 to 6 carbon atoms include a methoxycarbonyl group, a propoxycarbonyl group, etc.; examples of the dialkylamino group having 1 to 6 carbon atoms include a dimethylamino group, a diethylamino group, etc.; specific examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, etc.

[0014] Specific examples of the alkyl group which may be substituted with a group not participating in the reaction include a methyl group, an ethyl group, a propyl group, a butyl group, a sec-butyl group, a pentyl group, a hexyl group, a cyclohexyl group, an octyl group, a decyl group, a 2-methoxyethyl group, a 3-ethoxypropyl group, a 2-methoxycarbonylethyl group, a 2-dimethylaminoethyl group, a 2-cyanoethyl group, a trifluoromethyl group, a 3-chloropropyl group, and the like.

[0015] When the hydrocarbon group is an aryl group, as the aryl group, a monovalent aromatic organic group of a hydrocarbon ring system or a heterocyclic system can be used. When the aryl group is a monovalent aromatic organic group of a hydrocarbon ring system, the number of carbon atoms thereof is preferably 6 to 22, more preferably 6 to 14, still more preferably 6 to 10. Specific examples of the monovalent aromatic organic group of a hydrocarbon ring system include a phenyl group, a naphthyl group, an anthryl group, a phenanthryl group, a pyrenyl group, a perylenyl group, a pentacenyl group, and the like. When the aryl group is a monovalent aromatic organic group of a heterocyclic system, the hetero atom in the heterocyclic ring is sulfur, an oxygen atom, or the like. The number of carbon atoms of the monovalent aromatic organic group of a heterocyclic system is preferably 4 to 12, more preferably 4 to 8. Specific examples of the monovalent aromatic organic group of a heterocyclic system include a thienyl group, a benzothienyl group, a dibenzothienyl group, a furyl group, a benzofuryl group, a dibenzofuryl group, and the like. Some or all of the hydrogen atoms bonded to the carbon atom of the aryl group may be substituted with a group not participating in the reaction. Examples of the group not participating in the reaction include those shown as the group not participating in the reaction which may substitute the alkyl group described above. Further, as other groups not participating in the reaction, an oxyethylene group, an oxyethyleneoxy group, which are divalent groups for bonding two carbon atoms on the ring, can be mentioned. Specific examples of the aryl group which may be substituted by a group which does not participate in the reaction include a methylphenyl group, an ethylphenyl group, a hexylphenyl group, a methoxyphenyl group, an ethoxyphenyl group, a butoxyphenyl group, an octoxyphenyl group, a methyl(methoxy)phenyl group, a fluoro(methyl)phenyl group, a chloro(methoxy)phenyl group, a bromo(methoxy)phenyl group, a 2,3-dihydrobenzofuranyl group, and a 1,4-benzodioxanyl group.

[0016] Furthermore, when the hydrocarbon group is an aralkyl group, the number of carbon atoms in the aralkyl group is preferably 7 to 23, more preferably 7 to 16. In addition, the hydrogen bonded to the carbon atom of the aralkyl group is preferably 7 to 23, more preferably 7 to 16. Some or all of the atoms may be substituted with groups that do not participate in the reaction. Examples of the group that does not participate in the reaction include those groups exemplified above as the groups that may be substituted on the alkyl group and do not participate in the reaction. Specific examples of the aralkyl group which may be substituted by a group which does not participate in the reaction include a benzyl group, a phenethyl group, a 2-naphthylmethyl group, a 9-anthrylmethyl group, a (4-chlorophenyl)methyl group, and a 1-(4-methoxyphenyl)ethyl group.

[0017] When the hydrocarbon group is an alkenyl group, the alkenyl group preferably has 2 to 23 carbon atoms, and more preferably 2 to 20 carbon atoms. In addition, some or all of the hydrogen atoms bonded to the carbon atoms of the alkenyl group may be substituted with groups that are not involved in the reaction. Examples of the group that does not participate in the reaction include those groups that may be substituted on the alkyl group and that do not participate in the reaction, as well as the above-mentioned aryl groups. Specific examples of alkenyl groups which may be substituted by groups which do not participate in the reaction include vinyl groups, 2-propenyl groups, 3-butenyl groups, 5-hexenyl groups, 9-decenyl groups, 2-phenylethenyl groups, 2-(methoxyphenyl)ethenyl groups, 2-naphthylethenyl groups, and 2-anthrylethenyl groups.

[0018] R 4The number of carbon atoms of the alkyl group having 1 to 6 carbon atoms represented by is preferably 1 to 4, more preferably 1 to 3. Specific examples of the alkyl group having 1 to 6 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a sec-butyl group, a pentyl group, a hexyl group, a cyclohexyl group and the like.

[0019] Specific examples of the alkoxysilane (I) include (methoxy)trimethylsilane (Me3SiOMe), (ethoxy)trimethylsilane (Me3SiOEt), (ethoxy)triethylsilane (Et3SiOEt), (ethoxy)dimethyl(phenyl)silane (Me2PhSiOEt), (ethoxy)methyldi(phenyl)silane (MePh2SiOEt), (ethoxy di)dimethyl(vinyl)silane (Me2ViSiOEt), methylphenyldi(methoxy)silane (MePhSi(OMe)2), dimethyldi(methoxy)silane (Me2Si(OMe)2), di(ethoxy)dimethylsilane (Me2Si(OEt)2), di(ethoxy)(phenyl)vinylsilane (PhViSi(OEt)2), methyltri(methoxy)silane (MeSi(OMe)3), tri(ethoxy)methylsilane (MeSi(OEt)3), phenyltri(methoxy)silane (PhSi(OMe)3), phenyltri(ethoxy)silane (PhSi(OEt)3), vinyltri(methoxy)silane (ViSi(OMe)3), vinyltri(ethoxy)silane (ViSi(OEt)3), tri(methoxy)silane (HSi(OMe)3), tri(ethoxy)silane (HSi(OEt)3), tetra(methoxy)silane (Si(OMe)4), tetra(ethoxy)silane (Si(OEt)4), tetra(propoxy)silane (Si(OPr)4), tetra(butoxy)silane (Si(OBu)4) and the like.

[0020] On the other hand, the diacyl sulfides to be reacted with the alkoxysilanes are, for example, represented by the following general formula (II) (hereinafter, the diacyl sulfides represented by the general formula (II) may be referred to as "diacyl sulfide (II)"). (R 5 CO)2S (II)

[0021] In general formula (II), R 5 is a hydrocarbon group having 1 to 24 carbon atoms, and part or all of the hydrogen atoms bonded to the carbon atoms of the hydrocarbon group may be substituted with a group that does not participate in the reaction. R 5 Examples of the hydrocarbon group represented by include an alkyl group, an aryl group, an aralkyl group, an alkenyl group, etc., and these are the same as the alkyl group, aryl group, aralkyl group, alkenyl group, etc. shown in the description of R 1 R 2 and R 3 . Further, examples of the group that does not participate in the reaction include the groups that do not participate in the reaction shown in the description of R R 1 R 2 and R 3 in general formula (I). Regarding the number of carbon atoms in the hydrocarbon group, when the hydrocarbon group is an alkyl group, it is preferably 1 to 20, more preferably 1 to 18, still more preferably 1 to 12, and particularly preferably 1 to 6; when the hydrocarbon group is an aryl group, it is preferably 4 to 20, more preferably 4 to 18; when the hydrocarbon group is an aralkyl group, it is preferably 5 to 21, more preferably 5 to 19; when the hydrocarbon group is an alkenyl group, it is preferably 2 to 20, more preferably 2 to 18. Specific examples of these hydrocarbon groups include the hydrocarbon groups shown in the description of R 1 R 2 and R 3 in general formula (I).

[0022] Specific examples of the diacyl sulfide (II) include diacetyl sulfide ((MeCO)2S), dipropionyl sulfide ((EtCO)2S), dibutyryl sulfide ((PrCO)2S), diisobutyryl sulfide (( iExamples include PrCO)2S, dihexanoyl sulfide ((PentCO)2S), dibenzoyl sulfide ((PhCO)2S), bis(benzylcarbonyl) sulfide ((PhCH2CO)2S), dichrotonoyl sulfide ((MeCH=CHCO)2S), and the like.

[0023] The molar ratio of the diacyl sulfides to the alkoxysilanes can be arbitrarily selected. However, considering the yield of the thionoacyloxysilanes based on the alkoxysilanes, it is usually 0.4 or more and 300 or less, more preferably 0.5 or more and 200 or less, even more preferably 0.5 or more and 150 or less. Also, it may be 0.5 or more and 100 or less, 0.5 or more and 50 or less, 0.5 or more and 10 or less, or 0.5 or more and 5 or less.

[0024] In this embodiment, thionoacyloxysilanes represented by the following general formula (III) can be produced by the reaction of alkoxysilanes (I) and diacyl sulfides (II) (hereinafter, the thionoacyloxysilanes represented by the general formula (III) may be referred to as "thionoacyloxysilane (III)"). R 1 p R 2 q R 3 r Si(OR 4 ) 4-(p+q+r+s) [OC(=S)R 5 s (III)

[0025] In the general formula (III), p, q, r, s, R 1 , R 2 , R 3 , R 4 , R 5 , and R 6 have the same meanings as described above, and specific examples thereof include those shown in the general formulas (I) and (II) above. Also, s is an integer of 1 or more and 4-(p + q + r) or less, preferably an integer of 1 or more and 2 or less, and more preferably 1.

[0026] ​Specific examples of the thionoacyloxysilane (III) include trimethyl(thionoacetoxy)silane (Me3SiOC(=S)Me), triethyl(thionoacetoxy)silane (Et3SiOC(=S)Me), dimethyl(phenyl)(thionoacetoxy)silane (Me2PhSiOC(=S)Me), methyldi(phenyl)(thionoacetoxy)silane (MePh2SiOC(=S)Me), dimethyl(vinyl)(thionoacetoxy)silane (Me2ViSiOC(=S)Me), (ethoxy)dimethyl(thionoacetoxy)silane (Me2Si(OEt)[OC(=S)Me]), dimethylbis(thionoacetoxy)silane (Me2Si[OC(=S)Me]2), di(ethoxy)methyl(thionoacetoxy)silane (MeSi(OEt)2[OC(=S)Me]), tri(ethoxy)(thionoacetoxy)silane (Si(OEt)3[OC(=S)Me]), di(ethoxy)bis(thionoacetoxy)silane (Si(OEt)2[OC(=S)Me]2), tri(methoxy)(thionoacetoxy)silane (Si(OMe)3[OC(=S)Me]), di(methoxy)bis(thionoacetoxy)silane (Si(OMe)2[OC(=S)Me]2), trimethyl(thiobenzoyloxy)silane (Me3SiOC(=S)Ph), tri(eth oxy)(thiobenzoyloxy)silane (Si(OEt)3[OC(=S)Ph]), tri(methoxy)(thiobenzoyloxy)silane (Si(OMe)3[OC(=S)Ph]), and the like.

[0027] In the reaction step of this embodiment, a nucleophilic substitution reaction of alkoxysilanes, which are raw materials having an alkoxy group, with diacyl sulfides is involved. For example, when a monoalkoxysilane and diacyl sulfides are reacted, the reaction step involves the elimination of a carboxylic acid ester. The reaction step in this embodiment proceeds as shown in the following reaction formula (Scheme 1) in the presence of a Lewis acid catalyst containing a cation (M m+ ) of elements of Groups 3 to 15.

[0028] [Chemical formula] As shown in Scheme 1, it is considered that the cation of the Lewis acid catalyst coordinates to the oxygen atom of the diacyl sulfides, enhancing the nucleophilicity of the carbon atom of the carbonyl group and promoting the reaction.

[0029] In addition, as the alkoxysilanes, not only monoalkoxysilanes but also dialkoxysilanes, trialkoxysilanes, and tetraalkoxysilanes can be used. That is, the thionoacyloxysilanes obtained by the production method according to the present embodiment are of one type when using monoalkoxysilanes as raw materials, but are not limited to one type of thionoacyloxysilanes when using dialkoxysilanes, trialkoxysilanes, or tetraalkoxysilanes as raw materials. For example, when using dialkoxysilanes as raw materials, the produced thionoacyloxysilanes may be thionoacyloxysilanes with one alkoxy group substituted, thionoacyloxysilanes with two alkoxy groups substituted, or a mixture thereof. Furthermore, when using trialkoxysilanes as raw materials, the produced thionoacyloxysilanes may be thionoacyloxysilanes with one alkoxy group substituted, thionoacyloxysilanes with two alkoxy groups substituted, thionoacyloxysilanes with three alkoxy groups substituted, or a mixture thereof. In addition, when using tetraalkoxysilanes as raw materials, the produced thionoacyloxysilanes may be thionoacyloxysilanes with one alkoxy group substituted, thionoacyloxysilanes with two alkoxy groups substituted, thionoacyloxysilanes with three alkoxy groups substituted, thionoacyloxysilanes with four alkoxy groups substituted, or a mixture thereof.

[0030] In the reaction step in the present embodiment for producing thionoacyloxysilanes, a catalyst can also be used to promote the reaction. Preferred catalysts include acidic catalysts. As the acidic catalyst, various conventionally known acidic compounds can be used. As the conventionally well-known acidic compounds, compounds selected from sulfonic acid compounds, imide compounds thereof, and Lewis acid compounds containing elements of Group 3 to Group 15 are preferable.

[0031] As the sulfonic acid compound or its imide compound, perfluoroalkanesulfonic acids such as trifluoromethanesulfonic acid and pentafluoroethanesulfonic acid; bis(perfluoroalkanesulfonyl)imides such as bis(trifluoromethanesulfonyl)imide, bis(pentafluoroethanesulfonyl)imide, and bis(nonafluorobutanesulfonyl)imide ; etc. are preferably used. Among these, the sulfonic acid compound or its imide compound is more preferably bis(trifluoromethanesulfonyl)imide, bis(nonafluorobutanesulfonyl)imide, etc.

[0032] Also, as the Lewis acid compound containing elements of Group 3 to Group 15, halides, perchlorates, sulfonates, bis(perfluoroalkanesulfonyl)imide salts, hexafluoroantimonate salts, thiocyanate salts, etc. of these elements can be used.

[0033] Regarding the elements of Group 3 to Group 15, they are preferably selected from Group 3, Group 8, Group 13 to Group 15, more preferably selected from Group 3, Group 8, Group 13, or Group 15, and even more preferably elements selected from Group 8 or Group 13. More specifically showing these elements, they are preferably selected from scandium, yttrium, samarium, ytterbium, iron, ruthenium, copper, aluminum, gallium, indium, tin, and bismuth, more preferably selected from scandium, iron, ruthenium, aluminum, gallium, indium, tin, and bismuth, and even more preferably elements selected from iron, ruthenium, aluminum, gallium, and indium.

[0034] Therefore, more specifically showing the Lewis acid compounds containing those elements, scandium(III) chloride, titanium(III) chloride, titanium(IV) chloride, iron(III) chloride, iron(III) bromide, ruthenium(III) chloride, aluminum(III) chloride, gallium(III) chloride, indium(III) chloride, tin(IV) chloride, iron(III) perchlorate, scandium(III) trifluoromethanesulfonate, ytterbium(III) trifluoromethanesulfonate, iron(III) trifluoromethanesulfonate, copper(II) trifluoromethanesulfonate, aluminum(III) trifluoromethanesulfonate, gallium(III) trifluoromethanesulfonate, indium(III) trifluoromethanesulfonate, tin(IV) trifluoromethanesulfonate, bismuth(IV) trifluoromethanesulfonate, lanthanum(III) trifluoromethanesulfonate, praseodymium(IV) trifluoromethanesulfonate, neodymium(IV) trifluoromethanesulfonate, ytterbium(IV) trifluoromethanesulfonate, scandium(III) bis(trifluoromethanesulfonyl)imide, zinc(II) bis(trifluoromethanesulfonyl)imide, indium(III) bis(trifluoromethanesulfonyl)imide, tin(IV) bis(trifluoromethanesulfonyl)imide, indium(III) tris[bis(trifluoromethanesulfonyl)imide], iron(III) hexafluoroantimonate, indium(III) hexafluoroantimonate, iron(III) thiocyanate, indium(III) thiocyanate and the like can be mentioned. Among these compounds, those containing crystal water (hydrates) can also be used. Among these Lewis acid compounds, the catalyst is preferably a Lewis acid compound containing iron, indium, etc., and more specifically, indium(III) bis(trifluoromethanesulfonyl)imide scandium(III) bis(trifluoromethanesulfonyl)imide, iron(III) perchlorate and the like are preferred.

[0035] In addition, as the acidic catalyst, various conventionally known solid acid catalysts that are easy to separate and recover can also be used. As the solid acid catalyst, inorganic and organic ones can be used. Examples of the inorganic solid acid catalyst include solid inorganic substances such as metal salts and metal oxides. More specifically, it includes zeolites, mesoporous silica, montmorillonite having a cation of an element of Group 3 to Group 15 or a protonic hydrogen atom as shown in the description of the Lewis acid compound; inorganic solid acids using silica gel, heteropolyacid, carbon-based materials, etc. as carriers; etc. Examples of the types of zeolites include USY type, Y type, beta type, mordenite type, ZSM-5 type, etc. Regarding the silica / alumina ratio, generally, it is in the range of 3 to 2000, etc.

[0036] Among these inorganic solid acids, one or more selected from montmorillonite and zeolite are preferably used. Also, as the cation of the element of Group 3 to Group 15, a cation selected from tin(IV), indium(III), aluminum(III), iron(III), and scandium(III) is preferably used. More specifically showing the preferred inorganic solid acids, regarding montmorillonite, montmorillonite having a cation selected from tin(IV), indium(III), and scandium(III); montmorillonite K10 (available from Merck) having a protonic hydrogen atom; etc. can be mentioned. Also, regarding zeolite, USY zeolites selected from CBV780, CBV760, CBV720, CBV600 (all available from Zeolyst) having a protonic hydrogen atom; etc. can be mentioned.

[0037] Furthermore, as the solid acid catalyst, in addition to the above-mentioned inorganic solid acids, organic solid acids having acidic functional groups can also be used. The organic solid acids are polymers having acidic functional groups. Examples of the types of acidic functional groups include sulfonic groups, carboxyl groups, phosphoryl groups, etc. Examples of the types of polymers include Teflon (registered trademark) backbone polymers having perfluoro side chains, styrene-divinylbenzene copolymer polymers, etc. Specific examples of the organic solid acids include those having sulfonic groups, such as Nafion (NAFION (registered trademark), available from DuPont, Merck), Dowex (DOWEX (registered trademark), available from Dow Chemical, Merck), Amberlite (AMBERLITE (registered trademark), available from Rohm & Haas, Merck), Amberlyst (AMBERLYST (registered trademark), available from Dow Chemical, Merck), etc. More specifically, Nafion NR50, Dowex 50WX2, Dowex 50WX4, Dowex 50WX8, Amberlite IR120, Amberlite IRP-64, Amberlyst 15, Amberlyst 36, etc. can be mentioned. The catalyst used in the production method according to this embodiment can be used alone, or a plurality of catalysts can be used in any combination and ratio.

[0038] The amount of the catalyst relative to the raw material can be arbitrarily determined. In terms of molar ratio or weight ratio, it is usually about 0.0001 to 10, preferably about 0.001 to 8, and more preferably about 0.001 to 6.

[0039] The reaction in the reaction step can be carried out in a liquid phase or a gas phase state according to the reaction temperature, reaction pressure, etc. Also, as the form of the reaction apparatus, it can be carried out in various conventionally known forms such as batch type, flow type, etc. The reaction temperature is usually -20°C or higher, preferably -10 to 300°C, more preferably -10 ~200°C, and even more preferably 0 to 150°C. Also, when the reaction is carried out at room temperature, the temperature range of room temperature is usually 0 to 40°C, preferably 5 to 40°C, and more preferably 10 to 35°C. Furthermore, the reaction pressure is usually from 0.1 to 100 atmospheres, preferably from 0.1 to 50 atmospheres, more preferably from 0.1 to 10 atmospheres, and even more preferably from 0.5 to 5 atmospheres. The reaction time depends on the amount of raw materials, the amount of catalyst, the reaction temperature, the form of the reaction apparatus, etc. However, considering productivity and efficiency, it is usually from 0.1 to 1200 minutes, preferably from 0.1 to 600 minutes, more preferably from 0.1 to 300 minutes, and even more preferably about 30 to 240 minutes.

[0040] In addition, when the reaction is carried out in a liquid phase system, it can be carried out regardless of the presence or absence of a solvent. When using a solvent, as the solvent, various solvents that do not react with the raw materials and products can be used, such as hydrocarbons like decalin (decalin), decane; halogenated hydrocarbons like chlorobenzene, 1,2-dichlorobenzene, 1,3-dichlorobenzene, 1,2,3-trichlorobenzene, 1,2,4-trichlorobenzene; ethers like tert-butyl methyl ether, dibutyl ether; etc. The solvents can also be used by mixing two or more kinds in any combination and ratio. Also, when the reaction is carried out in a gas phase, an inert gas such as nitrogen can be mixed to carry out the reaction.

[0041] The reaction process can also be carried out under microwave irradiation. In this reaction system, the dielectric loss coefficients of diacyl sulfides, acid catalysts, etc. are relatively large, and they can efficiently absorb microwaves. Therefore, under microwave irradiation, diacyl sulfides, catalysts, etc. are activated, and the reaction can be carried out more efficiently.

[0042] In the microwave irradiation reaction, various commercially available devices equipped with contact or non-contact temperature sensors can be used. Also, the output of microwave irradiation, the type of cavity (multi-mode, single-mode), the form of irradiation (continuous, intermittent), etc. can be arbitrarily determined according to the scale of the reaction, the type of raw materials, the type of catalyst, etc. The frequency of microwaves is usually from 0.3 to 30 GHz. Among them, the preferred ones are the IMS frequency bands assigned for use in industrial fields, scientific fields, medical fields, etc. Among them, the 2.45 GHz band, 5.8 GHz band, etc. are more preferred.

[0043] In the microwave irradiation reaction, in order to heat the reaction system more efficiently, a heating material (susceptor) that absorbs microwaves and generates heat can be added to the reaction system. As the types of heating materials, various conventionally known materials such as activated carbon, graphite, silicon carbide, and titanium carbide can be used. Further, a molded catalyst obtained by mixing the powders of the catalyst and the heating material described above and performing firing using a suitable binder such as sepiolite or hormite can also be used.

[0044] The reaction process in this embodiment proceeds even in a closed reaction apparatus, but by making the reaction apparatus an open system and continuously removing the reaction product outside the reaction system, the reaction can also proceed more efficiently.

[0045] In the production method according to this embodiment, when using a solid acid catalyst, the separation and recovery of the catalyst after the reaction process can be easily performed by methods such as filtration and centrifugation. Also, the purification of the produced thionoacyloxysilanes can be easily achieved by means commonly used in organic chemistry such as distillation, recrystallization, and column chromatography.

Examples

[0046] Next, the present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to these examples. The main analytical instruments and the like used in the following examples are as follows. · Nuclear magnetic resonance spectrum analysis (hereinafter sometimes referred to as NMR): Bruker AVANCE III HD 600 MHz (equipped with a cryoprobe) · Gas chromatograph analysis (hereinafter sometimes referred to as GC): GC-2014 manufactured by Shimadzu Corporation · Gas chromatograph mass spectrometry (hereinafter sometimes referred to as GC-MS): GCMS-QP2010Plus manufactured by Shimadzu Corporation

[0047] (Example 1) (Ethoxy)trimethylsilane (Me3SiOEt) (1.0 mmol), diacetyl sulfide ((MeCO)2S) (1.1 mmol), and bis(trifluoromethanesulfonyl)imide (Tf2NH) (0.01 mmol) were placed in a reaction tube and stirred at approximately 25 °C (room temperature) for 0.5 h. The product was analyzed by GC, GC-MS, and NMR, and the yield was calculated by NMR. As a result, it was found that trimethyl(thionoacetoxy)silane (Me3Si[OC(=S)Me]) was produced in a yield of 83% (see Tables 1 and 2).

[0048] (Examples 2 to 22) The reaction and analysis were carried out in the same manner as in Example 1 by changing the reaction conditions (catalyst, raw materials, etc.) as shown in Table 1, and the yield of the product was calculated. The results are shown in Table 1. In addition, the spectral data of the obtained thionoacyloxysilanes are shown in Table 2.

[0049]

Table 1

[0050] The annotations in Table 1 are shown below. 1) Me3SiOEt: (Ethoxy)trimethylsilane Et3SiOEt: (Ethoxy)triethylsilane Me2PhSiOEt: (Ethoxy)dimethyl(phenyl)silane MePh2SiOEt: (Ethoxy)methyldi(phenyl)silane Me2ViSiOEt: (Ethoxy)dimethyl(vinyl)silane Me2Si(OEt)2: Di(ethoxy)dimethylsilane MeSi(OEt)3: Tri(ethoxy)methylsilane Me3SiOMe: (Methoxy)trimethylsilane 2) (MeCO)2S: Diacetyl sulfide 3) Tf2NH: Bis(trifluoromethanesulfonyl)imide (C4F9SO2)2NH: Bis(nonafluorobutanesulfonyl)imide In(NTf2)3: Indium(III) tris[bis(trifluoromethanesulfonyl)imide] III Sc(NTf2)3: Scandium(III) tris[bis(trifluoromethanesulfonyl)imide] (III) Fe(ClO4)3·6H2O: Iron(III) perchlorate hexahydrate Sc(OTf)3: Scandium(III) trifluoromethanesulfonate Mont-Sn 4+ : Sn 4+ Montmorillonite containing (Na + type montmorillonite (Kunipia F manufactured by Kunimine Industries Co., Ltd.) was treated with an aqueous solution containing Sn 4+ (solution prepared by dissolving SnCl4·5H2O in water) to carry out a cation exchange reaction to exchange Na + with Sn 4+ ). Mont-K10: Montmorillonite K10 (manufactured by Merck) CBV780: H-SDUSY type zeolite CBV780 (manufactured by Zeolyst, calcined at 500 °C before use) Amberlyst15: H + type cation exchange resin Amberlyst15 (manufactured by Merck) 4) Me3SiOC(=S)Me: Trimethyl(thionoacetoxy)silane Et3SiOC(=S)Me: Triethyl(thionoacetoxy)silane Me2PhSiOC(=S)Me: Dimethyl(phenyl)(thionoacetoxy)silane MePh2SiOC(=S)Me: Methyldi(phenyl)(thionoacetoxy)silane Me2ViSiOC(=S)Me: Dimethyl(vinyl)(thionoacetoxy)silane Me2Si(OEt)[OC(=S)Me]: (Ethoxy)dimethyl(thionoacetoxy)silane Me2Si[OC(=S)Me]2: Dimethylbis(thionoacetoxy)silane MeSi(OEt)2[OC(=S)Me]: Di(ethoxy)methyl(thionoacetoxy)silane 5) The yield was calculated by NMR. 6) Monosubstituted and disubstituted products were formed. The numbers in parentheses indicate the formation ratios, and the yields indicate the total yields.

[0051]

Table 2

[0052] The annotations in Table 2 are shown below. 1) For the name of thionoacyloxysilane (III), refer to Note 4 in Table 1. 2) Measured values in deuterochloroform 3) GC-MS (EI, 70eV)

Industrial Applicability

[0053] According to the production method of the present invention, thionoacyloxysilanes useful as functional chemicals can be produced more efficiently and safely. Therefore, the present invention has high utility value and great industrial significance. In addition, the thionoacyloxysilanes provided by the production method of the present invention have a thionoacyl-oxy group that is more reactive than an alkoxy group, have higher reactivity than alkoxysilanes as raw materials, and have the characteristic of having a sulfur atom. Therefore, it is considered that conversion to other functional groups of the thionoacyl-oxy group and physical property control of functional materials using siloxane-based compounds can be performed more efficiently, and they have high utility value as functional chemicals.

Claims

**Claim 1** A method for producing thionoacyloxysilanes, comprising: a reaction step of reacting alkoxysilanes with diacyl sulfides; wherein the alkoxysilanes are represented by the following general formula (I); wherein the diacyl sulfides are represented by the following general formula (II); a method for producing thionoacyloxysilanes, wherein the thionoacyloxysilanes are represented by the following general formula (III). R1pR2qR3rSi(OR4)4-(p+q+r) (I) (In the formula, p, q, and r are each independently an integer of 0 or more and 3 or less; p + q + r is an integer of 0 or more and 3 or less; R1, R2, and R3 are each independently a hydrocarbon group having 1 to 24 carbon atoms or a hydrogen atom, and a part or all of the hydrogen atoms bonded to the carbon atoms of the hydrocarbon group may be substituted with a group that does not participate in the reaction; R4 is each independently an alkyl group having 1 to 6 carbon atoms.) (R5CO)2S (II) (In the formula, R5 is a hydrocarbon group having 1 to 24 carbon atoms, and a part or all of the hydrogen atoms bonded to the carbon atoms of the hydrocarbon group may be substituted with a group that does not participate in the reaction.) R1pR2qR3rSi(OR4)4-(p+q+r+s)[OC(=S)R5]s (III) (In the formula, p, q, r, R1, R2, R3, R4, and R5 are as defined above; s is an integer of 1 or more and 4-(p + q + r) or less.) **Claim 2** The method for producing thionoacyloxysilanes according to claim 1, wherein the reaction step is carried out in the presence of a catalyst. **Claim 3** The method for producing thionoacyloxysilanes according to claim 2, wherein the catalyst is an acidic catalyst. **Claim 4** The method for producing thionoacyloxysilanes according to claim 3, wherein the acidic catalyst is an acidic compound selected from bis(perfluoroalkanesulfonyl)imide and metal salts thereof. **Claim 5** The method for producing thionoacyloxysilanes according to claim 3, wherein the acidic catalyst is a solid acid catalyst selected from montmorillonite and zeolite.

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