JPS5837293B2 - gamma carbon fiber - Google Patents

Description

Detailed Description of the Invention The present invention is based on the general formula (I) (wherein Rl and R2 are the same or different lower alkyl groups, R3 is a hydrogen atom or a lower alkyl group, and R is a lower alkyl group). It is.

) The present invention relates to a method for producing a γ-monounsaturated carboxylic acid ester represented by:

More specifically, the present invention relates to general formula (II) (In the formula, R1 and R2 are as defined above.

) and the allylic alcohol represented by the general formula (6) [wherein, R3 is as defined above, and R4 is the general formula (I
) is a lower alkyl group that is the same as or different from R in ().

] is reacted with the orthoester represented by The present invention relates to a method for producing an r-unsaturated carboxylic acid ester represented by the general formula (I), which comprises removing the following: and then adding a lower alkanol to the reaction mixture for treatment in the presence of an acidic catalyst.

The gamma-unsaturated carboxylic acid esters of general formula (i) are useful, for example, in the production of substituted cyclopropane carboxylic acid esters, which are important as insecticide intermediates, by the synthesis route described below.

(In the formula, R1, R2, R3 and R are as defined above, and the plurality of X's represent the same or different halogen atoms, preferably Cl, Br.

) Conventionally, a known method for producing γ-unsaturated carboxylic acid esters is to combine 3-methylcrotyl alcohol with vinyl ether, oxidize the resulting γ-unsaturated aprotic acid aldehyde, and esterify it. (J.
Am. Chem. Soc. , 8 2, 4 6 8
1-5 (1960)), this method cannot be said to be industrially preferred because the reaction steps are long.

Recently, a simple production method using the following reaction has been proposed.

The yield of gamma-monounsaturated carboxylic acid esters by this method is usually less than about 75% based on the allyl alcohol even when highly reactive orthoacetic esters are used; The yield is further reduced when the or-l ester is used.

The present inventors have conducted extensive research to produce r-unsaturated carboxylic acid esters in higher yields using the above reaction, and have found that after the above reaction, unreacted orthoesters are present in the reaction mixture. The present inventors have discovered that if it exists, it can be removed if desired, and then a lower alkanol can be added to the reaction mixture and the reaction mixture can be treated in the presence of an acidic catalyst.

When reacting the allyl alcohol represented by the general formula (E) with the orthoester represented by the general formula (E) in the presence of an acidic catalyst, examples of the acidic catalyst include acetic acid, propionic acid, butyric acid, isobutyric acid, and cyclohexanecarboxylic acid. ,
Lower fatty acids such as valeric acid, malonic acid, succinic acid, and adipic acid; Aromatic carboxylic acids such as benzoic acid and m-chlorobenzoic acid; Halogenated acetic acids such as monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, and monobromoacetic acid: Phenol, 0 -, m- or p-nitrophenol, 0-, m- or p-cresol, 0-, m- or p-xylenol, 2,6-dimethylphenol, 2,6-di-tert-butylphenol, 2,4- 6-trisec-butylphenol, 2,4,6-trit-butylphenol, 4-methy/l/-2,6-di-t-butylphenol, 4-methyl-3,5-di-t-butylphenol, hydroquinone , 2,5-di-t-butylhydroquinone, α- or β
Phenols of naphthogolenate: sulfonic acids such as benzenesulfonic acid and p-toluenesulfone; hydrochloric acid,
Mineral acids such as sulfuric acid, phosphoric acid, and boric acid; aluminum chloride,
Lewis acids such as zinc chloride, iron chloride, and boron trifluoride can be used, but preferred acidic catalysts have 2 carbon atoms.
~6 fatty acids, phenols, boric acid, and chlorogenic acetic acids.

The amount of acidic catalyst used is 0 based on the raw material allyl alcohol.
．． It is preferably within the range of 0.001 to 20% by weight, preferably 0.005 to 10% by weight.

A reaction solvent is not necessarily required, but if desired, a solvent that does not adversely affect the reaction may be used, such as n-octane, toluene, 0-, m- or p-xylene, di-n-butyl ether, or tetralin.

The orthoester represented by the general formula may be slightly decomposed in the presence of an acidic catalyst.

Therefore, it is preferable that the molar ratio of orthoester to raw material allyl alcohol be about 1.0 to 3.0 times.

Note that the orthoester may be used in large excess with respect to the allyl alcohol, so that the orthoester also serves as a solvent.

In this reaction, a lower alkanol is produced together with the γ-unsaturated carboxylic acid ester, and in order for the reaction to proceed effectively, it is necessary to carry out the reaction while distilling off the produced lower alkanol.

As the raw material allylic alcohol used here, alcohols in which R1 and R2 in general formula (I[) are lower alkyl groups having 15 or less carbon atoms, particularly methyl group, ethyl group, proyl group, butyl group, etc. are preferable. .

A specific example of a preferable allylic alcohol is 3-methyl-2-butenol (hereinafter referred to as prenol).
, 2-butenol and the like.

Also, as an orthoester, R3 in the general formula is an atom or group selected from the group consisting of a hydrogen atom and a lower alkyl group having 6 or less carbon atoms, especially a hydrogen atom, a methyl group, an ethyl group, a proyl group, and R4 is a methyl group,
It is preferable to use orthoesters which are lower alkyl groups having 1 to 5 carbon atoms such as ethyl group, probyl group, butyl group.

Specific examples of preferable orthoesters include ■・1・
1-trimethoxyethane, 1.1.l-triethoxyethane, 1.1.1-triflopoxyethane, 3-methyl-
1 ・1・1-}rimethoxybutane, 3-methyl-l・
1.i-triethoxybutane and the like can be mentioned.

After reacting the allyl alcohol and orthoester as described above, if any unreacted orthoester remains, it is removed if desired, and then a lower alkanol is added and treated in the presence of an acidic catalyst. By doing so, the desired γ-monounsaturated carboxylic acid ester can be obtained in good yield.

Examples of lower alkanols used here include methanol, ethanol, furopanol, inpropanol, and butanol.

In this case, it is particularly preferable to recover and use the alkanol produced during the reaction of the allyl alcohol and orthoester.

The amount of lower alkanol added is 1 to 30% of the remaining amount of allyl alcohol after subtracting the amount consumed by γ-unsaturated carboxylic acid ester from the amount of allyl alcohol charged.
It may be used in an amount of 3 to 10 times the mole, preferably 3 to 10 times the amount.

Examples of acidic catalysts include sulfonic acids such as p-}luenesulfonic acid and benzenesulfonic acid; mineral acids such as hydrochloric acid, sulfuric acid, phosphoric acid, and boric acid; aluminum chloride, zinc chloride,
Lewis acids such as iron chloride and boron trifluoride; halogenoacetic acids such as monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, and monobromoacetic acid can be used.

The amount of acidic catalyst used is about 0.001 to 10% by weight in the treatment mixture, preferably o. It is preferably within the range of oi to 1% by weight.

This treatment may generally be carried out at about 50 to 180°C for about 1 to 50 hours.

After this treatment, the γ-monounsaturated carboxylic acid ester can be isolated and obtained from the mixture by conventional separation operations.

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited by these Examples.

Example 1 Prenol 123? , 300 g of ethyl orthoacetate, and 7 g of phenol were placed in a 2-liter flask equipped with a stirrer, a thermometer, and a distillation column, and reacted at 140° C. for 15 hours.

After the reaction, unreacted ethyl orthoacetate was distilled off, 200 ml of ethanol and 0.1 z of p-}luenesulfonic acid were added to the residue, and the mixture was heated under reflux for 40 hours.

After the reaction, the reaction mixture was distilled to obtain 5.2z of ethylprenyl ether and 1.949f of ethyl 3,3-dimethyl-4-pentate.

Yield 87%. Example 2 1231 g of prenol, 280 g of methyl acetate, and 7 g of phenol were placed in a 2-liter flask equipped with a stirrer, a thermometer, and a distillation column, and reacted at 140° C. for 15 hours.

After completion of the reaction, 50 Cl of methanol and o. i y was added and heated under reflux for 45 hours.

The reaction mixture was distilled to obtain methyl 3,3-dimethyl-4-pentenoate as a fraction with a bp of 90 to 95°C.
．． 5? (yield 82%).

Example 3 Prenol 123P, ethyl orthoacetate 3002 and isobutyric acid 71 were reacted in the same manner as in Example 1.

After the reaction, the reaction mixture was distilled to give ethyl 3,3-dimethyl-4-pentenoate as a fraction at bp, 63°C.
6? Obtained.

Yield: 85% 0 Example 4 12.3 P of prenol, 302 P of ethyl orthoacetate, and 0.11 P of monochloroacetic acid were placed in a 200 rr Ll flask equipped with a stirrer, a thermometer, and a distillation column, and the mixture was heated at 140°C for 15
Allowed time to react.

The produced ethanol was distilled out of the reaction system through a distillation column.

After the reaction was completed, 50 ml of ethanol and sulfuric acid were added to the reaction mixture. oiy was added and the mixture was heated under reflux for 20 hours.

After reaction, reaction. The reaction mixture was distilled under reduced pressure to obtain bp, 62-64
17.42 (yield 78%) of ethyl 3,3-dimethyl-4-pentenoate was obtained as a fraction at °C.

Example 5 Prenol 1.23P, ethyl orthopropionate 7.
01 and Phenol '1, Orttl were placed in a 50771 L flask equipped with a stirrer, a thermometer and a distillation column, and reacted at 140°C for 20 hours.

The produced ethanol was distilled out of the reaction system through a distillation column.

After the reaction was completed, 10 ml of ethanol and 3 ml of p-1 toluenesulfonic acid were added to the reaction mixture, and the mixture was heated under reflux for 20 hours.

After the reaction, low-boiling substances were distilled off using an evaporator.

The residue was purified by column chromatography to obtain 1.71' (yield 73%) of a liquid ethyl 2,3,3-trimethyl-4-pentenoate having the following properties.

Boiling point: 97-99℃/37Hg Nuclear magnetic resonance absorption (δCCl4): TMS

Claims (1)

[Claims] 1 An allylic alcohol represented by the general formula (II) (wherein R1 and R2 are the same or different and are lower alkyl groups) and the general formula R3CH2C(OR4)3 (o]) (In the formula,
(R3 is a hydrogen atom or a lower alkyl group, and R4 is a lower alkyl group) is reacted with the orthoester represented by (R3 is a hydrogen atom or a lower alkyl group) in the presence of an acidic catalyst and while distilling off the lower alkanol produced, and the resulting reaction mixture is If unreacted orthoester is present, it is removed if desired, and then a lower alkano is added to the reaction mixture and treated in the presence of an acidic catalyst = general formula (I) (
(wherein Rl, R2 and R3 have the above meanings and R is a lower alkyl group which is the same as or different from R4 above). A method for producing a γ-monounsaturated carboxylic acid ester represented by