JPS58154535A - Synthesis of acetoacetic acid ester - Google Patents

Abstract

PURPOSE:To prepare the titled compound useful as an intermediate of dyes, pharmaceuticals and other synthetic organic chemicals, at a low temperature, in one step, in high yield, by reacting monohalogenated acetone with a lower alcohol and carbon monoxide in the presence of a basic substance and a catalyst. CONSTITUTION:A monohalogenated acetone (preferably chloroacetone, bromoacetone, or iodoacetone) is made to react with a lower alcohol and carbon monoxide in the presence of a basic substance preferably sodium carbonate, potassium carbonate, triethylamine, etc. and a cobalt carbonyl catalyst, preferably dicobalt octacarbonyl, at 10-150 deg.C. The amount of the basis substance is more than the stoichiometric amount necessary to react with the monohalogenated acetone and equimolar amount of hydrogen halide to form a halogenated product, and the amount of the catalyst is preferably 1/100-1/10mol per 1mol of the monohalogenated acetone.

Description

[Detailed description of the invention] The present invention relates to a method for synthesizing acetoacetate.

Acetoacetate is an important compound as an intermediate for dyes, pharmaceuticals, and other organic synthesis. Traditionally industrial! 'i n
As a method, acetic acid is dehydrated at 700°C using an aluminum phosphate catalyst to obtain ketene, which is then completely processed and cooled to form diketene/diketene, and diketene is reacted with alcohol in the presence of a sulfuric acid catalyst to form acetoacetate. A synthetic method has been adopted.

However, the rice cracking method has the disadvantage that the reaction temperature is high and many reactions must be performed.

The object of the present invention is to provide a synthetic method for obtaining acetoacetate in high yield at low temperatures and in one step, without such drawbacks.

In order to achieve this purpose, the inventor of the present application has conducted intensive research,
A process for the synthesis of acetoacetate, consisting of reacting monohalogenated acetone, lower alkyl and -carbon oxides in the presence of a total basic substance and a catalyst according to the invention has been achieved. That is, the horn method of the present invention is: X-ClI2-1:0-CIls+CO+R4→C1(
, -00-CH2-Coo R. (In the formula, X is a) rogen atom, and R is an alkyl group.) The heptadrogenated acetones used as raw materials in the present invention are chloroacetone, bromoacetone, and iodoacetone.

As the alcohol, lower alcohols such as methyl, ethyl, propyl, isopropyl, and butyl alcohol are used.

Although pure carbon monoxide is preferable, inert noble gases or those containing a small amount of hydrogen can also be used.

- The partial pressure of carbon oxide is between 1 and 100 atm, preferably between 1 and 5
It's 0 atm.

Basic substances include carbonates, monobicarbonates, acetates, and oxides of alkali metals and alkaline earth metals.

Hydroxides, alcoholades, and organic bases such as tertiary amines such as triethylamine and substituted pyridines are used;
Preferably, carbonate, potassium carbonate, triethylamine, lutidine, etc. are used.

The amount of the basic substance to be used is greater than the theoretical value required to react with mono-Rogge/acetone as a raw material and equimolar .-Rogge/hydrogen hydride to produce Rogge/hydrogen hydride.

As the catalyst, dicobalt octacarbonyl is preferably used, but tetracobalt dodecacarbonyl, hydrocobalt tetracardinyl and its sodium salt,
You can also use Conomaltoluponylanio/solution etc.

The amount of catalyst is 1/1000 to 115 mol, preferably 1/100 to 1 mol of mono-10-genated acetate.
~1/10 moles are used.

Although the reaction proceeds without a single solvent, organic solvents such as hydrocarbons, ethers, ketones, and esters can be used.

! ! Furthermore, when an inorganic base is used, addition of an appropriate amount of water improves the reaction rate.

Reaction temperature is 10° to 150°C, preferably 30 to 70°C
It is.

After the reaction, cool the autoclave and take out the reaction solution.
After completely removing the catalyst and base using a known method.

Acetoacetate can be obtained by distillation at normal pressure or under reduced pressure.

Next, examples of the present invention will be shown, but the present invention is not limited to the following examples unless it exceeds the gist of the present invention.

<Example 1> 200 CO stainless steel autoclave nimonoku o
/l/7 ce) 72.5d (30m'1jFIOt)
r ethanol 10-.

Toluzun lOmL water 2 wt, Na, 0032.1
? (20 lectures m6L).

002(10)a O, 6f f was charged, the gas phase was filled with carbon monoxide, and after e-digesting, -carbon oxide was injected up to 10 kf/-.

When the reaction was carried out at 55°C for 6 hours, the conversion rate of monochloroacetone was 88%, and the yield of ethyl acetoacetate was 82% (
(based on raw material monochloroacetone).

<Example 2> Same as Example 1 except that water was not added.
When the reaction was carried out at .degree. C. for 6 hours, the conversion of monochloroacetone was 12% and the yield of ethyl acetoacetate was 10%.

<Example 3> 2.5 d (30 mmot) of monochloroacetone and 2 d of methanol in a 200 CC stainless steel autoclave
0tn! .

Triethylamine 4.5 td (33 mmot)
, co, (10) aO,69 was charged, and after purging the gas phase with carbon monoxide, carbon monoxide was pressurized to 30 kg/cr/I.

When the reaction was carried out at 55° C. for 4 hours, the conversion of monochloroacetone was 93% and the yield of methyl acetoacetate was 76%.

<Example 4> 72.5 mm of monochloroacetate (30 mmot) and 20 mm of ethanol were placed in a 200 CC stainless steel autoclave.

26 lutezi/3.8 ml (33 mraot), 0
02 (10) 80.69 and the gas phase with carbon monoxide,
After the O-ji, carbon monoxide was pressurized to 30 kg/crA.

When the reaction was carried out at 55° C. for 4 hours, the conversion rate of monochloroacetone was 63% and the yield of ethyl acetoacetate was 62%.

Other than using n-pronominol as alcohol,
When the reaction was carried out at 55° C. for 4 hours in the same manner as in Example 4, the conversion of monochloroacetone was 62% and the yield of n-propyl acetoacetate was 60%.

<Example 6> In a 20,000 stainless steel autoclave, 25 g of monochloroacetone (30 grooves) + 20 g of methanol
Charge 7.4 m (33 tons) of 926-tert-butylpyridine and purge with gas phase total carbon monoxide.
Carbon monoxide was fully pressurized to 0 kV/cd.

When the reaction was carried out at 55° C. for 4 hours, the conversion of monochloroacetone was 23% and the yield of ethyl acetoacetate was 23%.

Procedural amendment (voluntary) January 11, 1980 Kazuo Wakasugi, Commissioner of the Japan Patent Office 1. Indication of the case 1982 Patent Application No. 035795 2. Name of the invention Method for synthesizing acetoacetate 3. Amendment. Patent applicant address: 1 Yozakicho, Chiba City, Chiba Prefecture Name: 4th Director, Kawatetsu Kagaku Co., Ltd. Address: 8-15-10 Ginza, Chuo-ku, Tokyo, 104
No. Ginza Dia Heights No. 410 Telephone: 03-542-091
11th line from the top of page 6 of the specification of contents of the 76 amendment, 5th line from the top of page 7, and 1
4th line no r 002 (10) II J k r 002
(00)11 Corrected to J.

“Butylpyridine 7, 4” on page 8 of the specification, line 10 from the top
ml (33rrvnoZ) J followed by r, 0
Insert 02(Co)II O, 6t, J.

Claims (9)

[Claims] (1) A method for synthesizing an acetoacetate, which comprises reacting a monohalogenated acetone, a lower alcohol, and a carbon oxide in the presence of a basic substance and a fluorocarzenyl catalyst. (2) The method of synthesis according to item 1, wherein the monohalogenated acetone is chloroacetone, bromoacetate/or iodoacetone. (3) The method of synthesis according to item 1, wherein the lower alcohol is methyl alcohol, ethyl alcohol, flobyl alcohol, isozorobyl alcohol, or butyl alcohol. (4) The partial pressure of the carbon oxide is 1 to 100 atm.
How to combine terms. (5) The synthesis method according to item 1, wherein the basic substance is an organic base such as a tertiary amine, pyridine, or substituted pyridine. (6) The basic substance is an alkali metal or alkaline earth metal carbonate monobicarbonate, acetate, or oxide. 1. Synthesis method using hydroxide or alcoholade. (7) The reaction is carried out by adding an appropriate amount of water.
How to compose one of the terms. (8) The method of synthesis according to item 1, wherein the catalyst is cobalt octacarzenyl, tetraconoltotecacarinyl, hydrocobalt tetracarzenyl or its sodium salt or cobalt cardanyl anion/solution. (9) The amount of the catalyst is 1 mole of monohalogenated acetone. . . ~ ] "The synthetic method of the first term, in which the amount is molar. The synthetic method of the first term, in which the QO reaction temperature is 10 to 150°C. 01) The synthetic method of the first term, in which the reaction is carried out in a solvent.