JPS58140041A - Preparation of halogenovinyl-substituted carboxylic ester - Google Patents

Abstract

PURPOSE:To prepare a carboxylic ester having the beta-position of an alkoxyl group thereof substituted by a halogenovinyl group, by reacting the carboxylic ester with a halogenated ethylene while irradiating the ester with high-energy radiation. CONSTITUTION:A carboxylic ester of formulaI(R1 is alkyl; R2 and R3 are H or alkyl), e.g. propyl acetate, is reacted with a halogenated ethylene of formula II (X1-X4 are halogen), e.g. tetrachloroethylene, to give a halogenovinyl-substituted carboxylic ester of formula III. In the process, the carboxylic ester is irradiated with high-energy radiation by using a radiation source, e.g. cobalt 60 or cesium 137, to give the aimed halogenovinyl-substituted carboxylic ester, e.g. 1-acetoxy-2-trichlorovinyl-propane. EFFECT:The aimed ester is obtained very easily in a relatively high yield. USE:A raw material for agricultural chemicals, food-type attractants, flame retardants, etc. and a synthetic intermediate for organic chemicals.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a vinyl halide-substituted carboxylic acid ester. β- of the alkoxy group of
The present invention relates to a method for producing a carbonyl ester having a structure substituted with a vinyl halide group at the position thereof.

In recent years, carboxylic acid esters in which the β-position of the alkoxy group of the ester has been substituted with an oral vinyl group have been used as raw materials for medicines, food attractants, flame retardants, and other useful organic chemicals. It is attracting attention as a synthetic intermediate.

However, when other substituents are generally introduced into the alkoxy group of an ester, the hydrogen atom at the α-position of the alkoxy group is most likely to be substituted. The actual situation is that production is extremely difficult, and thus conventional methods have been required that require a large number of complicated steps and have low yields.

The present inventors have conducted intensive research on a method to overcome the drawbacks of such conventional methods and obtain the above-mentioned vinyl halide substituted carboxylic acid ester easily and in good yield.
The inventors discovered that the objective could be achieved by reacting a carboxylic acid ester with a halogenated ethylene under irradiation with high-energy radiation, and based on this knowledge, the present invention was completed.

A carboxylic acid ester represented by R, CO・○CH2CH—R3 (R in the formula is an alkyl group, R2 and R3 are a hydrogen atom or an alkyl group) and a general formula (X in the formula, % X2・X3 and X4 is a halogen atom) by reacting the halogenated ethylene represented by the formula (R1, R2, R3, xl, x2 and x3 have the same meanings as above) to produce a halogenated vinyl lf represented by the general formula The present invention provides a method for producing a vinyl halide substituted carboxylic acid ester, which comprises irradiating high-energy radiation in producing the substituted carboxylic acid ester.

The carboxylic acid ester used as a raw material in the method of the present invention has a structure represented by the following general formula (I) 2 R, (!O・0OH2C!H-R3...(1), where R1 is an alkyl groups, R2 and R
3 is a hydrogen atom or an alkyl group, preferably R1
is an alkyl group having 1 to 10 carbon atoms, R2 and R3 are a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and especially R2
It is preferable that R3 is a hydrogen atom or the sum of the carbon numbers of R2° and R3 is 1 to 3, and these alkyl groups may be linear or branched. As such, for example, ethyl acetate, propyl acetate, butyl acetate, pentyl acetate, ethyl propionate, propyl propionate, butyl propionate, pentyl propionate, etc. are preferably used.

The no-logenated ethylene used as another raw material in the method of the present invention has a structure represented by the general formula (II) 2 x3 1 x, -c = c -X4 - (II), in which X, X2, X3 and X
4 is a halogen atom, which may be the same or different, and preferred examples of such atoms include tetrafluoroethylene, tetrachloroethylene, tetrachlorethylene, dichlorodibromoethylene, etc. nCarbon in the method of the present invention The molar ratio of acid ester and rogenated ethylene is 100.
The range of :1 to 1:10 is preferred, especially 1 of 4:l.
The u-coupling is preferred.

Furthermore, in the method of the present invention, the irradiation temperature ranges from room temperature to 200°C.
A range of 0.degree. C. is preferred; higher irradiation temperatures generally reduce the yield of the desired ester. ``The source of high-energy radiation used in the method of the present invention is preferably a radioactive isotope such as cobalt-60 or cesium-137, and a radiation generator may also be used.The dose of this radiation is usually 1 to 1.
The range is 100 MRad, and the irradiation time varies depending on the dose rate, but is usually 10 to 1000 hours. At low dose rates, the longer the irradiation time, the better the yield.

In the method of the present invention, α-substituted compounds and α-
Positionally substituted compounds are also obtained, and the production rate of these compounds can be varied by changing the irradiation conditions.

According to the method of the present invention, carboxylic acid esters in which the β-position of an alkoxy group is substituted with a vinyl halide group, which had conventionally been obtained through complicated steps and in low yields, can be obtained extremely easily and with relatively high yields. obtained in high yield. This halogenated vinyl-substituted carboxylic acid ester is useful as a raw material for agricultural chemicals, food attractants, flame retardants, etc., and as a synthetic intermediate for other useful organic chemicals.

Next, the present invention will be explained in more detail with reference to Examples.

Example 1 A compound of propyl acetate 122.56 F (1.2 mol) and tetrachloroethylene 49.751 (0.3 mol) was sealed in a sealed tube under reduced pressure, and the dose rate was determined using Kobal) 60 as a γ-ray source. Irradiation was carried out at 25° C. for 197 hours at 1×105 R/hr. After irradiation, unreacted raw materials are distilled off and the oil content 14.
42 I got f. Fractional distillation of oil content bp79.0-83.0
'C/ 6.58 t of 1-acetoxy-1-trichlorovinyl-propane at 8 mm Hg (9.5% yield
) and bp55.0-56.0℃/3mmHg (d24
°1.3201 + n2. '1.4874, chlorine content 45.96%) 4.08 r of 1-acetoxy-2-trichlorovinyl-propane (yield 5.8%) was obtained.

Example 2 A mixture of 139.39 y (1.2 mol) of butyl acetate and 49.75 t (0.3 mol) of tetrachloroethylene was sealed in a sealed tube under reduced pressure, and the dose rate I was set using cobalt-60 as a γ-ray source. 1 at 25°C at X 105R/hr
It was irradiated for 97 hours. After irradiation, unreacted raw materials are distilled off and oil content 14
．． I got 841. This oil is distilled to a BP of 79.0~
A fraction of 9.99 f was obtained at 101.2°C/7 mx Hg. This fraction was fractionated and bp 88.0~sc+, o℃
/8 Hg of 1-acetoxy-1-trichlorovinyl-butane with 1.54 f (yield 6.3%) and bp 96
．． 5-98.5℃/8 Hg (d24゜1.2714
r n2o1.4836, chlorine content 43.43%)
1-acetoxy-2-trichlorovinyl-butane 7
．． 50 y (yield 21.5%) Example 3 Propyl propionate 116.15 y (1,0 mol) Trichlorethylene 41.45 y (0,25
A mixture of cobalt 60 moles) was sealed in a sealed tube under reduced pressure and
2 x 10' R/hr of γ-rays at a dose rate of 2
It was irradiated for 02 hours. After irradiation, unreacted raw materials are collected and crude oil is obtained.8.
Obtained 30 tons. Distill the crude oil to bp 85.0-102
．． 0 °C / 8 vm Hg fraction 5.53 f was obtained.
This fraction was further fractionated to obtain bp 68.0 to 68.3.
1-propionyloxy-1- at °C/3 mm Hg
1.05 t of trichlorovinyl-propane (yield: 1
．． 7%) and bp 62.0-63.0℃/3mHg (
d41.2565, n2:1.4767,
1-propionyloxy- with a chlorine content of 43.54%)
2-Trichlorovinyl-propane 1.159 (Ll 1
．． 8%).

Example 4 Butyl propionate 1B0.181i+ (1.0 mo/
L/ ) and 41.45 g of tetrachlorethylene (0,2
5 mol) was sealed in a sealed tube under reduced pressure, and the cobalt 6
γ-rays from zero were irradiated for 202 hours at a dose rate of 2×105 R/hr. After irradiation, unreacted raw materials are recovered and crude oil 11.17
I got f. The crude oil was distilled to a bp of 89. o~125'C/
A fraction of 7.90f/g was obtained. Further fractional distillation of the fraction with 'bp87.0~88.5°C/:lllll
1.25 g (yield 1.9%) of 1-propionyloxy-1-trichlorovinylbutane of Ig and bp7
8, 0-74.0°C/3) (g of 1-propionyloxy-2-trichlorovinylbutane (ζ2.' 1
2811, η1.4787, chlorine content 41.
00%) 2.50 g (yield 8.vb) was obtained.

Claims (1)

[Scope of Claims] 1 Carboxylic acid ester represented by the general formula % formula % (R in the formula is an alkyl group, R2 and R3 are hydrogen atoms or alkyl groups) and the general formula % formula % (in the formula XI, X2, X3 and Production of a halogenated vinyl substituted carboxylic acid ester characterized by irradiation with high energy radiation in producing the halogenated vinyl substituted carboxylic acid ester represented by X, X2 and X3 are halogen atoms. Method.