JPS58131931A - 2-(4-ethoxyphenyl)-2-methylpropyl alcohol and its preparation - Google Patents

Abstract

NEW MATERIAL:2-(4-Ethoxyphenyl)-2-methylpropyl alcohol of formulaI. USE:A synthetic intermediate of pyrethroid insecticides. PREPARATION:4-Ethoxyphenylacetonitrile of formula II is alkylated with an alkylating agent in the presence of a base to give 2-(4-ethoxyphenyl)-2-methylpropionitrile of formula III. Then, the product is hydrolyzed in the presence of an acid or base to give 2-(4-ethoxyphenyl)-2-methylpropionic acid of formula IV The acid is, when needed, esterified, then reduced to give the compound of formulaI.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to u2-(a-ethoxyphenyl)-2-methylpropyl alcohol and a method for producing the same.

2-(4-Ethoxyphenyl)-2-methylpropyl alcohol is a new compound and a compound useful as an intermediate for pyrethroid cenocidals.

In recent years, synthetic pyrethroid insecticides have been in the spotlight for their excellent R and fast-acting properties, as well as their outstanding effectiveness against organophosphate- or carbamate-resistant pests, and their relatively low toxicity to humans and livestock. I came flying. However, the disadvantage of this synthetic pyrethroid insecticide is that it is highly toxic to fish, which limits its range of use.

Recently, the present inventors #'i5-phenoxybenzyl 2-(
4-Ethoxyphenyl)-2-methylpropyl ether has extremely high insecticidal and acaricidal activity, has an excellent immediate and residual effect, and has an excellent % mold, and is effective not only against humans and livestock, but also against fish GLLK. We found that the toxicity is relatively low.

2-(4-Ethoxyphenyl)-2-methylpropyl alcohol is useful as an intermediate raw material for 3-phenoxybenzyl 2-(4-ethyl)+diphenyl)-2-methylpropyl ether, which is useful as an insecticide. This is a novel compound that has never been synthesized before.

As a method for producing 2-(4-ethoxyphenyl)-2-methylpropyl alcohol, 4-ethoxyphenyl and methallyl chloride are reacted in the presence of an acid catalyst.
One possible method is to react ethoxyneophyl chloride with metallic magnesium and then oxidize it, but the reaction between ethoxybenzene and methallyl chloride produces isomers of monolithic and p monolithic, and the yield of monolithic p is low. 〇One piece and p
It is difficult to isolate the whole.

To avoid this point, 4-ethoxyphenylacetonitrile is methylated with a methylating agent such as methyl halide, and then the obtained 2-(4-ethoxyphenyl)-2-
Methylpropionitrile is hydrolyzed in the presence of an acid or a base to convert it to 2-(4-ethoxyphenyl)-2-methylpropionic acid, and the carboxylic acid or carboxylic acid is esterified with an alkylating agent. Although it requires many steps, it is advantageous to reduce the lower alkyl ester of the carboxylic acid.

An example manufacturing route is shown diagrammatically below.

References C, A, 64.12595. h(196
tS)R: Lower alkyl group 4-ethoxyphenylacetonitrile can be dimethylated in the presence of an inert solvent or with a methylating agent such as methyl halide in the presence of a base such as sodium hydride. bases such as sodium hydroxide, potassium hydroxide, calcium hydroxide, sodium carbonate, potassium carbonate, calcium carbonate, aqueous sodium carbonate, potassium bicarbonate, etc., in the presence or absence of an inert solvent; Methylation is carried out using a methylating agent such as a methyl halide in the presence of a phase transfer catalyst such as a quaternary ammonium salt or a quaternary phosphonium salt. Quaternary ammonium salts: tetramethyl ammonium, tetraethyl ammonium, tetrabutyl ammonium, trimethyl ammonium
Phenyl ammonium, triethyl phenyl ammonium, tributyl phenyl bone ammonium, trimethyl benzyl 9 ammonium, triethyl benzyl ammonium, tributyl ammonium, trimethyl phenyl ethyl ammonium,
Mention may be made of triethyl e phenylethyl a/monium chloride, tributyl phenylethyl ammonium chloride, bromide or iodite.

Quaternary phosphonium salts include tetramethyl phosphonium, tetraethyl phosphonium, tetrabutyl phosphonium, trimethyl phenyl phosphonium, triethyl phenyl phosphonium, triphthyl phenyl phosphonium, trimethyl benzyl Φ phosphonium, tributyl 1 benzyl phosphonium, and tributyl. 1 Benzyl phosphonium, tributyl p/:) le.
phosphonium, trimethyl phenylethyl phosphonium, triethyl phenylethyl phosphonium,)
Examples include chloride, bromide or iodite of IJ phthyl O phenylethyl phosphonium.

Hydrolysis of 2-(a-ethoxyphenyl)-2-methylpropionitrile is carried out in the presence of an acid or an alkali. As the acid, sulfuric acid, hydrochloric acid, p-)lue/sulfonic acid, glacial acetic acid, etc. can be used.

As the base, sodium hydroxide, potassium hydroxide, alkoxides such as propyl alcohol potash and amyl alcohol potash, etc. can be used.

Optionally, it may be hydrolyzed in ethylene glycol or glycerin.

The reduction of carboxylic acid may be carried out as it is, as an acid chloride, or as a lower alkyl ester.

The lower alkyl ester can be obtained by esterifying 2-(4-ethoxyphenyl)-2-methylpropionic acid by a conventional method.

2-(4-z)xyphenyl)-2-methylpropionic acid or its lower alkyl esters can be reduced with lithium aluminum hydride or sodium borohydride-aluminum chloride reducing agent in the presence of an inert solvent. Good, sodium and alcohol Bouveau
The lt-Blanc method may also be used. It can also be reduced by catalytic reduction. Adkins for catalytic reduction
A copper-chromium catalyst of 2-(4-ethoxyphenyl)=2-methylpropyl alcohol can be obtained in a yield of <2-(4-ethoxyphenyl)=2-methylpropyl alcohol when carried out at a hydrogen pressure of 100 to 400 atm and a temperature of 100 to 250 DEG C.

Hereinafter, details of the present invention will be explained by way of examples.

Example 1 Synthesis of 2-(4-ethoxyphenyl)-2-methylpropyl alcohol (4-ethoxyneophyl alcohol) +1) 2-(4-ethoxyphenyl)-2-methylpropyl alcohol synthesized according to the following sequence. Synthesis of nitriles 4-ethoxybe/:) lunitrile 28ON,) ethylbenzylammonium bromide 5oIi.

Potassium hydroxide 750.9. When 750I of water was charged into the 2J Cenozo Rubble Flask and stirring was started, the internal temperature was approximately 85.
It rose to ~90°. To this, methyl iodide 180111
4 (approximately 410 Ii) was added dropwise over 1.5 hours.

Stirring was then continued for an additional 7 hours at 80-90°C. After cooling the reaction solution to room temperature, it was extracted with 500 d of benzene, and the benzene extract was washed with dilute hydrochloric acid and water in that order, followed by sulfuric anhydride.)
It was dried at 179 mm. Benzene was distilled off under reduced pressure to obtain 311 crude 2-(4-ethoxyphenyl)propionitrile.
I got g.

112-(4-ethoxyphenyl)propionitrile obtained above 311,9. ) Ethylbenzylammonium bromide 11ON, potassium hydroxide aoo,y, and water 5ooIi were placed in a 21 separable flask and stirred.

Next, methyl iodide 180111 (approximately 41.On) was added dropwise at 85 to 90°C over 1.5 hours.
After a period of time, potassium hydroxide 3001 was additionally charged. After 5 hours, 50 d of methyl iodide (approximately 1-1-
Added 8l4. The reaction was further continued at the same temperature for 2 hours. From now on
Crude 2-(4-ethoxyphenyl) was treated in the same manner as in the synthesis of 2-(4-ethoxyphenyl)propionitrile below.
Specializes in -2-methylpropionitrile 340I.

Purification was carried out by distillation under reduced pressure to obtain 275 g of the desired product.

(111-b +2) Synthesis of 2-(4-ethoxyphenyl)-2-methylpropionic acid 275 g of 2-(4-ethoxyphenyl)-2-methylpropionitrile, 850 g of potassium hydroxide, 700 g of water
1j, while stirring ethylene/glycol 2000M
The reaction was carried out under reflux at 21-126°C for 8 hours. After the reaction mixture was cooled to room temperature, it was poured into 2-3I water, and the neutral part was removed with benzene. The water pigeon was adjusted to -2 or less with concentrated hydrochloric acid and extracted with benzene. The benzene extract was washed with water, dried over anhydrous sodium sulfate, and after distilling off the benzene, it was recrystallized from n-hexane. m, p, 80.5-82.5℃+
2) 240 g of 2-(71-eth)-1-diphenyl)-2-methylpropionic acid was obtained.

13) Synthesis of ethyl 2-(4-ethoxyphenyl)-2-methylpropionate (2) by adding 24.0 J of the carbo/acid to 40 ON of benzene.
After dissolving in ethanol 2001117, 25- concentrated sulfuric acid is added and the azeotropic mixture of ethanol and water is refluxed. It was added dropwise over a period of time. After cooling the reaction product to room temperature, water was added to separate the benzene particles. The resulting benzene solution was washed with water until it became neutral and then dried. Benzene was distilled off under reduced pressure. The desired ester 264I was obtained.

(4) 2-(4-ethoxy, diphenyl)-2-methylpropyl alcohol f) Synthesis Dry tetrahydrofuran 40011jK To a system to which 35 g of lithium aluminum hydride was added was added 264 g of the ester obtained in K (3) under stirring at a temperature of 50°C. It was dropped while keeping the temperature below.

Reflux the ester under the skin for 30 minutes. Next, the mixture was rolled up to decompose excess lithium aluminum hydride, and 508 J of ethyl acetate was added dropwise under water cooling. When heat generation and foaming were no longer observed, water was added at key points to completely decompose the lithium aluminum hydride.

The produced precipitate was removed by vacuum filtration, and the tetrahydrofuran was distilled off under reduced pressure. Extract with Inzea 500d,
Wash the extract with water and dry it. Under reduced pressure (-/in is distilled off,
2-(4-ethoxyphenyl)-2-methylpropyl alcohol (213 Jll).

m, p,: 42.0~4&5℃Br y ((X-'): !+400.1620.152
0.1255.1195°ax 1050.850 J';' (ppm): 1.21 (s, 6H), 1
．． 57ct, J=7Hg, 5H) 2.26(s, IH)
, 3.31 (s, 2B).

Engineering 89 (q −J ” 7Hz −2H) *465
~7.25 (m, 4H) Example 2 Example 1 (4) was carried out in Example 1 (2) using a special carboxylic acid. The charging of the carboxylic acid was carried out in the same manner as in Example 1 (4) except that it was carried out under reflux conditions.
2-' (4-ethoxypher)-2 with lyq-like yield
-Methylpropyl alcohol was obtained.

Agent Patent Attorney 1) Parent Male

Claims (1)

[Claims] +1) 2-(4-ethoxyphenyl)-2-methylpropyl acycol. (2) 2-(4-ethoxyphenyl)-2- characterized by reducing 2-(4-ethoxyphenylv)-2-methylpropionic acid or its lower alkyl esters
Method for producing methylpropyl alcohol. 13) In the method for producing 2-(4-ethoxyphenyl)-2-methidipropyl alcohol, 2-(4-ethoxyphenyl)-2-methylpropionitrile is hydrolyzed in the presence of an acid or a base to obtain the 7'j 2-(a-ethoxyphenyl)-2-methyl characterized by reducing lower alkyl esters obtained by esterifying 2-(4-ethoxyphenyl)-2-methylpropionic acid or nuclear propionic acid Method for producing propyl alcohol. (412-(4-Ethoxyphenyl)-2-methylpropyl alcohol is produced by methylating 4-ethoxyphenylacetonitrile with a methylating agent in the presence of a base to produce 2-(4-ethoxyphenyl)-2-methylpropyl alcohol. Lower alkyl obtained by producing pionitrile, hydrolyzing the nuclear nitrile in the presence of an acid or base, and converting the resulting 2-(4-ethoxyphenyl)-2-methylpropionic acid or Fi-added dipropionic acid ester. 2-(4-ethoxyphenyl)-, which is characterized by reducing esters to esters.
Method for producing 2-methylpropyl alcohol.