Method for producing bis(tetraalkylammonium) oxalate

Abstract

The object of the present invention is to efficiently produce a target bis(tetraalkylammonium) salt of oxalate by reacting a trialkylamine with a dialkyl oxalate. [Solution] The problem of the present invention is solved by a method for producing bis(tetraalkylammonium) oxalate, in which a trialkylamine and a dialkyl oxalate are reacted under conditions where the trialkylamine / dialkyl oxalate (molar ratio) is 2.3 to 5.0 and the reaction pressure is greater than 1.0 MPa.

Description

[Technical Field]

[0001] The present invention relates to a method for producing bis(tetraalkylammonium) oxalate. Bis(tetraalkylammonium) oxalate can be converted into tetraalkylammonium hydroxide by a known method. Among the aforementioned tetraalkylammonium hydroxides, tetramethylammonium hydroxide is a useful compound applicable, for example, as a developer for positive photoresists that is indispensable in the production of ultra-large-scale integration, as a pretreatment agent for gas chromatography, as a surface treatment agent for regenerated fibers and polyester fibers, as a peptizer for clay, and as an alkaline electrolyte for secondary batteries. [Background Art]

[0002] Conventionally, as a method for producing bis(tetraalkylammonium) oxalate from a trialkylamine and a dialkyl oxalate, for example, a method is known in which dimethyl oxalate and trimethylamine in an amount twice the mole of dimethyl oxalate are reacted at 130°C for 8 days without a solvent (see, for example, Non-Patent Document 1). [Prior Art Documents] [Non-Patent Documents]

[0003] [Non-Patent Document 1] Zeitschrift fuer Anorganische und Allgemeine Chemie(1995),621(10),1735~40. [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] However, Non-Patent Document 1 does not contain a detailed description of reaction conditions, nor does it contain any description of the yield or the like of the target product, bis(tetraalkylammonium) oxalate. The object of the present invention is to efficiently produce a target bis(tetraalkylammonium) salt of oxalate by reacting a trialkylamine with a dialkyl oxalate. [Means for solving the problem]

[0005] The present invention relates, for example, to the following [1] to [4]. [1] Trialkylamine and dialkyl oxalate, The trialkylamine / dialkyl oxalate (molar ratio) is 2.3 to 5.0. The reaction is carried out under conditions where the reaction pressure exceeds 1.0 MPa. A method for producing bis(tetraalkylammonium) oxalate. [2] The method for producing the above reaction in an organic solvent, as described in [1]. [3] The manufacturing method according to [1] or [2], wherein the trialkylamine / dialkyl oxalate (molar ratio) is 2.4 to 5.0. [4] The manufacturing method according to any one of [1] to [3], wherein the reaction pressure is 3.0 to 7.0 MPa. [Effects of the Invention]

[0006] The present invention provides an industrially suitable method for producing bis(tetraalkylammonium) oxalate salts under mild conditions, with good reaction efficiency and without complicated reaction operations or post-treatment. [Modes for carrying out the invention]

[0007] The present invention will be described in detail below.

[0008] (The reaction of the present invention) The present invention provides a manufacturing method in which a trialkylamine and a dialkyl oxalate are used. The trialkylamine / dialkyl oxalate (molar ratio) is 2.3 to 5.0. The reaction is carried out under conditions where the reaction pressure exceeds 1.0 MPa. This is a method for producing bis(tetraalkylammonium) oxalate.

[0009] (Trialkylamine) Examples of the aforementioned trialkylamines include trimethylamine, triethylamine, tripropylamine, tributylamine, trihexylamine, trioctylamine, dimethylethylamine, diethylmethylamine, dimethylpropylamine, dipropylmethylamine, dimethyldecylamine, dimethyllaurylamine, dimethyloctylamine, dimethylstearylamine, methyldilaurylamine, dimethyldodecylamine, dimethylhexadecylamine, dimethyloctadecylamine, N,N-dimethylethanolamine, N,N-diethylethanolamine, and N,N-diisopropylamine. Examples include tanolamine, N,N-dibutylethanolamine, N-methyldiethanolamine, triethanolamine, N,N-dimethylbenzylamine, N,N-diethylbenzylamine, N,N-dimethylaniline, N,N-dimethylcyclohexylamine, N,N'-tetramethylethylenediamine, and N,N'-tetramethyl-1,3-propanediamine, but trimethylamine, triethylamine, tripropylamine, tributylamine, dimethylethylamine, diethylmethylamine, N,N-dimethylethanolamine, and more preferably trimethylamine. The trialkylamine may be used as is (gas, liquid, or solid) or as a solution obtained by dissolving it in an organic solvent, as described later.

[0010] (Dialkyl oxalate) Examples of the dialkyl oxalate include dimethyl oxalate, methyl ethyl oxalate, methyl propyl oxalate, methyl butyl oxalate, diethyl oxalate, ethyl propyl oxalate, ethyl butyl oxalate, dipropyl oxalate, propyl butyl oxalate, and dibutyl oxalate, but preferably dimethyl oxalate, methyl ethyl oxalate, diethyl oxalate, dipropyl oxalate, and dibutyl oxalate, and more preferably dimethyl oxalate and diethyl oxalate.

[0011] (Amount used) In the reaction of the present invention, the trialkylamine / dialkyl oxalate (molar ratio) is 2.3 to 5.0, preferably 2.4 to 5.0, and more preferably 3.0 to 5.0. By using this range, the target bis(tetraalkylammonium) oxalate salt can be efficiently obtained.

[0012] (Reaction pressure) The reaction pressure in the present invention is greater than 1.0 MPa, preferably greater than 3.0 MPa, and more preferably between 3.0 and 7.0 MPa. By keeping the pressure within this range, the target bis(tetraalkylammonium) oxalate salt can be efficiently obtained.

[0013] (Reaction temperature) The reaction temperature in this invention is not particularly limited, but is preferably 80 to 150°C, and more preferably 90 to 130°C. By using this range, the desired bis(tetraalkylammonium) oxalate salt can be efficiently obtained.

[0014] (organic solvent) The reaction of the present invention is preferably carried out in an organic solvent. Examples of the organic solvent used include alcohols such as methanol, ethanol, isopropyl alcohol and t-butyl alcohol; glycols such as ethylene glycol, diethylene glycol, triethylene glycol and low-molecular-weight polyethylene glycol; amides such as formamide, N-methylformamide, N-ethylformamide, N,N-dimethylformamide, N,N-diethylformamide, acetamide, N-methylacetamide, N-ethylacetamide, N,N-dimethylacetamide, N,N-diethylacetamide, N-methylpyrrolidone and N-ethylpyrrolidone; nitriles such as acetonitrile, propionitrile, butyronitrile, valeronitrile, acrylonitrile, methacrylonitrile and benzonitrile; ethers such as tetrahydrofuran, cyclopentyl methyl ether and diethyl ether; and alkylbenzenes such as toluene, xylene, ethylbenzene and cumene. Alcohols are preferred, and methanol and ethanol are more preferred. The amount of the organic solvent used is preferably 1 to 100 mol, more preferably 2 to 50 mol, still more preferably 5 to 10 mol, per 1 mol of the trialkylamine.

[0015] (Reaction Atmosphere) The reaction of the present invention is preferably carried out in an inert gas atmosphere, and examples of the inert gas used include nitrogen, helium, argon and carbon dioxide.

[0016] (Isolation and Purification) The bis(tetraalkylammonium) oxalate salt obtained by the reaction of the present invention can be isolated and purified by common methods such as filtration, concentration, distillation, recrystallization, crystallization and column chromatography after completion of the reaction. The bis(tetraalkylammonium) oxalate salt can be converted to tetraalkylammonium hydroxide by a known method such as electrolytic decomposition or electrodialysis, and in this case, a crude bis(tetraalkylammonium) oxalate salt that has not undergone the aforementioned isolation and purification may also be used. EXAMPLES

[0017] Next, the present invention will be specifically described with reference to examples, but the scope of the present invention is not limited thereto.

[0018] In the examples and comparative examples, quantification of bis(tetramethylammonium) oxalate and methylmono(tetramethylammonium) oxalate was performed using 1H-NMR.

[0019] Example 1 (Synthesis of bis(tetramethylammonium) oxalate) 0.76 g (6.4 mmol) of dimethyl oxalate and 6.05 g of a 25% by mass methanol solution of trimethylamine (amount of trimethylamine: 25.6 mmol, trimethylamine / dimethyl oxalate (molar ratio) = 4.0) were added into a SUS pressure-resistant container with an internal volume of 50 mL, and the reaction was allowed to proceed at 5 MPa and 120°C for 25 hours under a nitrogen atmosphere. After completion of the reaction, methanol was distilled off under reduced pressure to obtain 1.42 g of bis(tetramethylammonium) oxalate as a colorless solid (yield: 93.8%). The physical property values of the bis(tetramethylammonium) oxalate are as shown below. 1H-NMR (DMSO-d6, δ (ppm)): 3.10 (s, 24H)

[0020] Examples 2 to 3, Comparative Examples 1 to 2 (Synthesis of bis(tetramethylammonium) oxalate) A reaction was carried out in the same manner as in Example 1, except that the amounts of each raw material used and the reaction conditions were changed as shown in Table 1. The results are shown in Table 1. The physical property values of the precursor methylmono(tetramethylammonium) oxalate are as shown below. 1H-NMR (DMSO-d6, δ (ppm)): 3.12 (s, 12H), 3.49 (s, 3H)

[0021] Table 1

[0022] The abbreviations used in the table are as follows: TMA: Trimethylamine DMO: Dimethyl oxalate Bis(Tetramethylammonium) Oxalate: Mono-form: Methyl mono(tetramethylammonium) oxalate nd: Below the detection limit

[0023] As is clear from Table 1, the manufacturing method of the present invention makes it possible to efficiently obtain the target bis(tetraalkylammonium) oxalate salt.

Claims

1. Trialkylamine and dialkyl oxalate, The trialkylamine / dialkyl oxalate (molar ratio) is 2.3 to 5.

0. The reaction is carried out under conditions where the reaction pressure exceeds 1.0 MPa. A method for producing bis(tetraalkylammonium) oxalate.

2. The manufacturing method according to claim 1, wherein the above reaction is carried out in an organic solvent.

3. The manufacturing method according to claim 1, wherein the trialkylamine / dialkyl oxalate (molar ratio) is 2.4 to 5.

0.

4. The manufacturing method according to claim 1 or 2, wherein the reaction pressure is 3.0 to 7.0 MPa.

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