Prepn process of 3-amino-4-cetyl chlorobenzoate

Abstract

The present invention relates to the preparation process of 3-amino-4-cetyl chlorobenzoate. Compound 3-amino-4-cetyl chlorobenzoate is prepared with 3-amino-4- chlorobenzoic acid and cetanol as main material, and tin tetrachloride, stannous chloride or butyl titanate as catalyst, and through solvent reflux dewatering and esterification. The preparation process includes the following steps: setting 3-amino-4- chlorobenzoic acid and cetanol into organic solvent, heating to dissolve and adding catalyst via stirring, reflux dewatering, recovering solvent after reaction and adding refined organic solvent, filtering to obtain solid, re-crystallizing in refined organic solvent and stoving to obtain 3-amino-4-cetyl chlorobenzoate product. The present invention has great production capacity and high product purity, and is suitable for industrial production.

Description

technical field [0001] The invention relates to hexadecyl 3-amino-4-chlorobenzoate, in particular to a preparation method of hexadecyl 3-amino-4-chlorobenzoate, and belongs to the technical field of organic acid ester synthesis. Background technique [0002] Hexadecyl 3-amino-4-chlorobenzoate is an important photosensitive material intermediate. The photosensitive material synthesized from this product has the characteristics of high reactivity, good oil solubility, and high light and thermal stability. [0003] At present, the preparation method of hexadecyl 3-amino-4-chlorobenzoate has: ① take 3-amino-4-chlorobenzoic acid and hexadecane bromide as starting raw materials, prepare under alkaline conditions; ② use 3-Amino-4-chlorobenzoic acid and cetyl alcohol as starting materials, prepared under acidic conditions. [0004] The first method is characterized by mild reaction conditions, rapid reaction, and high yield, which can be found in European patent EP853077; but the h...

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Problems solved by technology

[0004] The first method is characterized by mild reaction conditions, rapid reaction and high yield, which can be found in European patent EP853077; but the high price of hexadecane bromide makes the production cost of this method relatively high, and it is difficult to have a market competitive advantage

However, method ② uses cheap cetyl alcohol to replace expensive cetyl bromide in method ①, and prepares hexadecyl 3-amino-4-chlorobenzoate by esterification under the condition of sulfuric acid as a catalyst. Can refer to Japanese patent JP9286766; Although the raw material price is low, because the activity of cetyl alcohol is lower than cetyl bromide, so the reaction is difficult to carry out, concentrated sulfuric acid has strong oxidizing property, is unfavorable for high-temperature esterification reaction, raw material cetyl The amount of alcohol should be excessive by 300%, which is not conducive to recovery and product purification

A large excess of cetyl alcohol not only weakens the industrial production capacity, but also increases the post-treatment recovery process, and it is quite difficult to separate cetyl 3-amino-4-chlorobenzoate from a large amount of cetyl alcohol, and there are technical defects in product purification ; Difficult to achieve large-scale industrial production