Preparation method of 4, 4-dimethyl-3-oxo-methyl pentanoate

A technology of methyl valerate and dimethyl valerate, applied in the field of preparation of 4,4-dimethyl-3-oxo-methyl valerate, which can solve the problems of high sodium hydride content, large consumption of raw materials, and high price , to achieve the effect of high distillation yield and high product purity

A technology of methyl valerate and dimethyl valerate, applied in the field of preparation of 4,4-dimethyl-3-oxo-methyl valerate, which can solve the problems of high sodium hydride content, large consumption of raw materials, and high price , to achieve the effect of high distillation yield and high product purity

CN106397200AInactive Publication Date: 2017-02-15ZHANGJIAGANG CITY ZHENFANG CHEM
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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0017] The preparation method of 4,4-dimethyl-3 oxo-valeric acid methyl ester:

[0018] (1), carry out condensation reaction under acidic condition by chloropentane and formaldehyde, carry out catalysis with Zn / Co / Sb composite catalyst, reaction temperature is 60 ℃, reaction time is 5h, prepare pinatone, Zn / The ratio between the sum of the amount of substance of each component in the Co / Sb composite catalyst and the amount of substance of chloropentane is 3:50;

[0019] (2) Using pinacolone, sodium hydride and dimethyl carbonate as raw materials, toluene as solvent, stirring and reacting at 55-60°C and then cooling to prepare 4,4-dimethyl- 3 Oxo-methyl valerate crude product, pinatone water content<0.2Wt.%, toluene water content<0.2Wt.%;

[0020] (3), the crude product of 4,4-dimethyl-3-oxo-valeric acid methyl ester is distilled at a vacuum degree of less than 10mm Hg and a temperature of 90°C, and the obtained 4,4-dimethyl-3-oxo - Methyl valerate has high purity and high y...

Embodiment 2

[0023] The preparation method of 4,4-dimethyl-3 oxo-valeric acid methyl ester:

[0024] (1) Condensation reaction of pentapentane chloride and formaldehyde under acidic conditions, catalyzed by a Zn / Co / Sb composite catalyst, the reaction temperature is 85°C, and the reaction time is 5h to prepare pinacolone, Zn / Sb The ratio between the sum of the amount of substance of each component in the Co / Sb composite catalyst and the amount of substance of chloropentane is 3:50;

[0025] (2) Using pinacolone, sodium hydride and dimethyl carbonate as raw materials, toluene as solvent, stirring and reacting at 55-60°C and then cooling to prepare 4,4-dimethyl- 3 Oxo-methyl valerate crude product, pinatone water content<0.2Wt.%, toluene water content<0.2Wt.%;

[0026] (3), the crude 4,4-dimethyl-3-oxo-valeric acid methyl ester is distilled at a vacuum degree of less than 10mm Hg and a temperature of 95°C, and the obtained 4,4-dimethyl-3-oxo - Methyl valerate has high purity and high yield,...

Embodiment 3

[0028] The preparation method of 4,4-dimethyl-3 oxo-valeric acid methyl ester:

[0029] (1), carry out condensation reaction under acidic condition by chloropentane and formaldehyde, carry out catalysis with Zn / Co / Sb composite catalyst, reaction temperature is 75 ℃, reaction time is 5h, prepare pinatone, Zn / The ratio between the sum of the amount of substance of each component in the Co / Sb composite catalyst and the amount of substance of chloropentane is 3:50;

[0030] (2) Using pinacolone, sodium hydride and dimethyl carbonate as raw materials, toluene as solvent, stirring and reacting at 55-60°C and then cooling to prepare 4,4-dimethyl- 3 Oxo-methyl valerate crude product, pinatone water content<0.2Wt.%, toluene water content<0.2Wt.%;

[0031] (3), the crude 4,4-dimethyl-3-oxo-valeric acid methyl ester is distilled at a vacuum degree of less than 10mm Hg and a temperature of 95°C, and the obtained 4,4-dimethyl-3-oxo - Methyl valerate has high purity and high yield, the m...

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Abstract

The invention discloses a preparation method of 4, 4-dimethyl-3-oxo-methyl pentanoate. The method includes: taking pinacolone, sodium hydrogen and dimethyl carbonate as the raw materials, and using toluene as the solvent, carrying out stirring reaction at 55-60DEG C, then performing cooling, and at a pH of 4-5, preparing a 4, 4-dimethyl-3-oxo-methyl pentanoate crude product; and subjecting the 4, 4-dimethyl-3-oxo-methyl pentanoate crude product to distillation under the conditions of a vacuum degree of less than 10mm Hg and a temperature of 90-95DEG C. By means of the method provided by the invention, the 4, 4-dimethyl-3-oxo-methyl pentanoate has high distillation yield, the product purity is high, the main content is up to more than 98%, and the total yield is up to 96%.

Description

technical field [0001] The application relates to a preparation method of 4,4-dimethyl-3 oxo-pentanoic acid methyl ester. Background technique [0002] 4,4-Dimethyl-3-oxo-valeric acid methyl ester is an intermediate of a color former and a new type of photosensitive material intermediate. [0003] In the prior art, the synthetic method of 4,4-dimethyl-3 oxo-methyl pentanoate mainly adopts: take methyl pivalate and dry methyl acetate as raw materials, sodium hydride as catalyst, and toluene as Solvent, at 60-70°C, stirring and reacting, then cooling, standing and layering when the pH is 4-5, removing the solvent and extracting 4,4-dimethyl-3-oxo-pentanoic acid methyl ester by vacuum distillation , but this method consumes a lot of raw materials, uses a high content of sodium hydride, is particularly dangerous when adding materials, and is also very expensive. [0004] Therefore, this project is to overcome the shortcomings of the existing technology and provide a method wit...

Claims

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Application Information

Patent Timeline
15 Feb 2017
Publication
CN106397200A
IPC
C07C67/313; C07C69/716
CPC
C07C67/313; C07C69/716
Inventors
曹爱春; 赵松雪