JPH0733763A - Production of cyclosulfites - Google Patents

Abstract

PURPOSE:To obtain the subject compounds useful as a synthetic raw material in the organic chemical field in good yield with excellent operating efficiency by subjecting dials and a thionyl halide to the cyclizing reaction in the presence of an alicyclic tertiary amine. CONSTITUTION:Diols expressed by formula I [R1 to R6 are H, hydrocarbon residue, etc.; (n) is 0 or 1] are reacted with a thionyl halide in the presence of an alicyclic tertiary amine (e.g. N-ethylmorpholine) in a solvent (e.g. methylene chloride) at -20 to +20 deg.C for 0.5-10hr to afford these compounds expressed by formula II. The thionyl halide is used in an amount of 1-10mol based on 1mol diols and the alicyclic tertiary amine is used in an amount of 1-10mol based on 1mol diols. 1,3,2-Dioxathiolan-4-yl-methyl 2-oxide methacrylate is cited as the compounds expressed by formula II. The post-treatment after the reaction is simply carried out without any problem in toxicity according to this method.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing cyclosulfites.

[0002]

2. Description of the Related Art Cyclosulfites have hitherto been used as useful synthetic raw materials in the field of organic chemistry. As a method for producing such cyclosulfates, for example, a method in which thionyl chloride and 2,3-dihydroxypropyl methacrylate are subjected to a cyclization reaction in the presence of pyridine is known (US Pat. No. 4,401,797). However, in this method, the yield is low at about 70%, the safety is poor due to the use of highly toxic pyridine, and the post-reaction post-treatment is difficult due to the use of hygroscopic pyridine. There was a point.

[0003]

DISCLOSURE OF THE INVENTION As a result of intensive investigations by the present inventors to solve the above problems, cyclosulfites can be obtained in high yield by using an alicyclic amine instead of pyridine. The inventors have found that there is no problem in terms of toxicity and that the operability is excellent, and that post-treatment after the reaction is simple, and the present invention has been completed based on this finding.

[0004]

Thus, according to the present invention, a process for producing cyclosulfites is characterized by cyclizing a diol and a thionyl halide in the presence of an alicyclic tertiary amine. Will be provided.

The diols of the present invention have two hydroxyl groups at different carbon atoms in the molecule, and are represented by the structural formula (1), for example.

[Chemical 1] (In the formula, R ₁ , R ₂ , R ₃ and R ₄ are a hydrogen atom or a hydrocarbon residue which may have a substituent, and R ₅ and R ₆ have a hydrogen atom or a substituent. R _{1 to} R ₆ may be combined in any combination to form a ring, and n is 0 or an integer of 1 or more.) R ₁ ,
R ₂ , R ₃ and R ₄ are hydrogen atoms or alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, pentyl group, hexyl group and octyl group; aryl groups such as phenyl group and naphthyl group Hydrocarbon residues such as Among these, a hydrogen atom or an alkyl group is preferable. Further, these hydrocarbon residues may have the following substituents. As a substituent, an alkoxycarbonyl group such as a methoxycarbonyl group and an ethoxycarbonyl group; a trifluoromethyl group, 1,2-
Examples thereof include halogenated hydrocarbon residues such as a dichloroethyl group.

Examples of R ₅ and R ₆ are a hydrogen atom and the same hydrocarbon residue as above. Examples thereof include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, pentyl group, hexyl group, and octyl group; and hydrocarbon residues such as aryl groups such as phenyl group and naphthyl group. Among these, a hydrogen atom or an alkyl group is preferable. Further, these hydrocarbon residues may have the following substituents. As a substituent, an alkoxycarbonyl group such as a methoxycarbonyl group or an ethoxycarbonyl group; a halogen atom such as a fluorine atom or a chlorine atom; an alkenylcarbonyloxy group such as an acryloyloxy group or a methacryloyloxy group; a cyano group; a hydroxyl group; a nitro group or the like Is exemplified. Among these substituents, a cyano group or an alkenylcarbonyloxy group is preferable, and an alkenylcarbonyloxy group is particularly preferable.

Examples of the thionyl halide include thionyl chloride, thionyl bromide, thionyl fluoride and the like, among which thionyl chloride is preferable. The amount of thionyl halide used is usually 1 to 1 mol of diols.
10 mol, preferably 1 to 5 mol, more preferably 1
~ 3 moles.

As the alicyclic tertiary amine, N-methylpiperidine, N-ethylpiperidine, N-methylmorpholine, N-ethylmorpholine, N-phenylmorpholine, N-ethylpyrrolidine, hexamethylenetetramine, 1,4 -Diazabicyclo [2,2,2] octane,
1,5-diazabicyclo [4,3,0] non-5-ene, 1,8-diazabicyclo [5,4,0] undeca
7-ene and the like are exemplified. Among these, N-ethylpiperidine, N-ethylmorpholine or 1,4-diazabicyclo [2,2,2] octane is preferable. The amount of the alicyclic tertiary amine used is based on 1 mol of the diol.
Usually, it is 1 to 10 mol, preferably 1 to 5 mol, more preferably 1 to 3 mol.

A diluent can be present during the reaction. The diluent is not particularly limited as long as it is inert to the reaction, and examples thereof include halogenated hydrocarbons such as methylene chloride and chloroform; esters such as methyl acetate and ethyl acetate; nitriles such as acetonitrile and propionitrile. Ethers such as tetrahydrofuran and dimethoxyethane; aromatic hydrocarbons such as benzene and toluene are used.

The reaction temperature is usually -20 to + 20 ° C, preferably -10 to + 10 ° C. The reaction time is usually
It is 0.5 to 10 hours, preferably 0.5 to 5 hours.

A salt of an alicyclic tertiary amine and hydrogen halide is formed in the reaction solution after the reaction is completed, and this is removed by filtration. Next, the cyclosulfite compound can be obtained by subjecting the filtrate to a conventional method such as extraction, recrystallization or distillation. The cyclosulfites thus obtained have the structure represented by the formula (2).

[Chemical 2]

[0012]

EXAMPLES The present invention will be described in more detail with reference to the following examples. Parts and% in the examples and comparative examples are based on weight unless otherwise specified.

Example 1 Under a nitrogen atmosphere, 10 mmol of 2,3, -dihydroxypropyl methacrylate and 25 mmol of N-ethylmorpholine were dissolved in 15 ml of methylene chloride, and chloride containing 11.5 mmol of thionyl chloride was cooled with ice. 5 ml of methylene solution was added dropwise in 20 minutes. Immediately after the dropping, white hydrochloride was formed. It was confirmed by gas chromatography that the raw materials disappeared 30 minutes after the completion of the dropping. The hydrochloric acid salt in the reaction solution was removed by filtration, and the filtrate was concentrated under reduced pressure to give 1,3,2-dioxathiolane-2-oxide-4-ylmethyl methacrylate of 2.0.
Gram (100% yield) was obtained.

Example 2 The procedure of Example 1 was repeated except that N-ethylpiperidine was used in place of N-ethylmorpholine, and 1,3,2-dioxathiolane-2-oxide-4-ylmethyl methacrylate was obtained. 2.0 grams (100% yield) was obtained.

Example 3 The procedure of Example 1 was repeated except that 1,4-diazabicyclo [2,2,2] octane was used in place of N-ethylmorpholine, and 1,3,2-dioxathiolane methacrylate was obtained. 2-Oxido-4-ylmethyl is 2.0
Gram (100% yield) was obtained.

Claims (1)

[Claims] 1. A method for producing cyclosulfites, which comprises subjecting a diol and a thionyl halide to a cyclization reaction in the presence of an alicyclic tertiary amine.