JPS62111977A - Production of 2,2-dimethyl-delta-valerolactone - Google Patents

Abstract

PURPOSE:To obtain the titled compound easily in high yield, from an easily available raw material, by adding hydrogen bromide to 2,2-dimethyl-4-pentenoic acid using benzoyl peroxide as a catalyst and treating the product with an alkali. CONSTITUTION:The objective compound of formula III can be produced by adding hydrogen bromide to the compound of formula II at -10-+70 deg.C, preferably -10-+40 deg.C using benzoyl peroxide as a catalyst and treating the resultant 2,2-dimethyl-5-bromovaleric acid of formula II with an alkali (e.g. in a 5-50% aqueous solution containing 1-3 times mol of an alkali at 0-50 deg.C). The amount of benzoyl peroxide is preferably 0.05-5wt%, especially 0.1-2wt% based on the starting compound. The compound of formula III is useful as a raw material of the compound of formula IV useful as a remedy for lipogenous hyperproteinemia, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a process for producing 2.2 dimethyl δ valerolactone. 2.2 Dimethyl δ valerolactone is a compound having a -(CH2)sO(C+H5)2000H group in the compound, such as L manufactured by His Company, which is effective as an antilipidemia drug.
It is useful as a raw material for products such as Op1d).

Prior Art Conventionally, the following method is known as a method for producing 2.2 dimethyl δ valerolactone.

1) A method in which 2.2 dimethylgeltal acid anhydride is reduced with metallic soda in absolute alcohol.

(J, QC, vol, as l j410 (19
70) pp. 3574-3576).

2) 2,2 dimethyl vinyl butyrate and C0(00
) 4 (Belgian Patent No. 6161141)
issue).

3) A method of preparing lithium isopropylamide from butyllithium and isopropylamine, reacting it with sodium isobutyrate, and then reacting it with dibromopropane for alkali treatment (USP No. 3674+836).

4) Method for transferring the acetal of allyl alcohol of isobutyraldehyde (5ynth, Oommnl
o(4) 273 (1980).

5) Add f[su, HBr] to the acetal of ethylene glycol of acroreish to make a Grignard reagent,
A method of reacting with bromoisoacetic acid and then hydrolyzing and lactonizing it.

The IItzi of the lactone is poor due to steric hindrance within the h-law phase molecule of (-2-2-17.1). Method 2) is Kobal l
-J) Since a foreign reagent such as rubonyl is used, handling is difficult and expensive. Method 3) uses expensive chemicals such as butyllithium, resulting in high costs. (
In the case of the JJ "method V1 a+tar transformation of 4), the reaction time is long and the yield is poor, resulting in high costs. The method (5) has its own drawbacks, such as high raw material costs and high costs.

OBJECT OF THE INVENTION The present invention has been made to overcome the drawbacks of conventional methods.The purpose of the present invention is to use readily available raw materials without using special or expensive drugs, and to easily produce a product with good yields. The object of the present invention is to provide a method for producing 2,2 dimethyl δ valerolactone at a low cost and at a high rate.

Structure of the Invention The inventor of the present invention has achieved the following objectives: As a result of theoretical research, 2,2 dimethylbendenoxic acid was used as a raw material, HBr was added to it using benzoyl peroxide, and 2,
It was discovered that 2+2 dimethyl δ valerolactone could be easily obtained in good yield by preparing 2 dimethyl 5 bromozoic acid and treating it with an alkali. 2 was obtained.

The reaction formula is as follows.

Based on this knowledge, we completed the present invention bνL5.

The gist of the present invention is to add HBr to 2.2 dimethylpentenoic acid using benzoyl peroxide as a catalyst to produce 2,2 dimethyl 5-bromovaleric acid, which is then treated with an alkali.
A method for producing 2-dimethyl δ valerolactone.

The 2,2-dimethylpentenoic acid used in the method of the present invention can be easily prepared, for example, by rearranging isoacetic acid allyl ester using sodium hydride. () to be. The reaction formula is as follows.

aH (OH3) 2041 (iooOH2・01 GH2-one 0H2=OH-0■12G(O1'b) 2000H
L7 Fushi is not limited to this method.2.2 Dimethyl 5-glomovaleric acid can be treated with an alkali. Any alkali such as NaOHr, Na2CO3, etc. may be used, but NaO
In the case of H, it is necessary to neutralize after the reaction, but Na2(]0
5 does not require this, so Na2005 is preferable.

Example 1 4 units equipped with a stirrer 1 separatory funnel, wetness meter, and condenser
A ¥j4 flask was charged with 64 v of 2,2 dimethyl 4-pentenoic acid and 0014300 cc of a solvent, and the mixture was stirred and dissolved. To this was added anhydrous NaBr 567 as a powder and suspended. Next, add benzoyl peroxide (1,5r
In addition, 27.5V of H2SO4 was gradually added dropwise at room temperature while stirring, and the reaction was continued for 2 hours after completion of the dropwise addition. The reaction product is soaked in the aqueous layer of Na2SO4 dispersed in water, and the reaction product is deposited in the aqueous layer, so the solvent layer is separated, washed with water and dehydrated, and then By collecting and cooling the bromine product (j) 7'''-0, it was washed with water at
=, 10% soda ash solution was added. Next, the extract was extracted with benzene to remove benzene from the extract, which was then fractionated under reduced pressure.

Hatsutome ~108/19 7V Hondome 108~113/19 43.7 r yield 6
It was 7.9% (purity 97.1%).

Additional Example 2 The flask of Example 1 was charged with 2.2 dimethyl 4-pentenoic 1d64r and 300 cc of benzene as a solvent, and dissolved with stirring.

0.51 i' of benzoyl peroxide was added to the dough, and HBr gas was blown into the dough at room temperature for 2 to 3 hours while stirring. After the blowing was completed, stirring was continued for 2 hours, and then the reaction product liquid was washed with water and the solvent was recovered. The amount of benzene recovered was 204, and the remaining liquid was 106.
It was v.

10% NaOH was added to this residual liquid to make it slightly alkaline, and benzene 100 (!(!) was added thereto for extraction.

Add 1f1 charcoal to the aqueous layer, and after 1 filtration, add HCl and p
The mixture was adjusted to 4.0 H and further extracted with benzene. Benzene was removed from this benzene liquid, and fractional distillation was performed under reduced pressure.

Hatsutome ~108/20 fight 9v Hondome 108~113/20mm 42.9 r4v
The percentage i was 66.7% (purity 97.2%).

Effects of the Invention According to the method of the present invention, easily available raw materials are used without using specific or expensive drugs.1.
Since it is easily obtained in good yield, 2+2 dimethyl δ can be obtained at low cost.
Valerolactone has excellent effects.

Claims (1)

[Claims] 2, characterized by adding HBr to 2,2 dimethylpentenoic acid using benzoyl peroxide as a catalyst to produce 2,2 dimethyl 5-bromovaleric acid, and treating it with an alkali.
A method for producing 2-dimethyl δ valerolactone.