CN102924245A

CN102924245A - Alcoholysis process of trimethyl orthoacetate

Info

Publication number: CN102924245A
Application number: CN2012104311570A
Authority: CN
Inventors: 谭建平; 顾银军; 奚一平
Original assignee: Nantong Tendenci Chemical Co Ltd
Current assignee: Nantong Tendenci Chemical Co Ltd
Priority date: 2012-11-02
Filing date: 2012-11-02
Publication date: 2013-02-13

Abstract

The invention discloses an alcoholysis process of trimethyl orthoacetate. Developing basis during pH regulation is provided accurately through utilization of a methyl-red indicator; additionally, ammonia is fed into frozen methanol, the utilization rate of the ammonia can be improved, and pollution to the environment can be reduced simultaneously; and the process is efficient, environment-friendly and accurate.

Description

A kind of alcoholysis process of trimethyl orthoacetate

Technical field

The invention belongs to chemical field, specifically a kind of production technique of trimethyl orthoacetate alcoholysis procedures invention.

Background technology

Ethanimidic acid methyl ether hydrochloride generates trimethyl orthoacetate by alcoholysis, and its alcoholysis process is the important procedure of preparation trimethyl orthoacetate crude product.

Summary of the invention

The invention of this technique provides the Optimization Technology in the trimethyl orthoacetate alcoholysis procedures, is the technique of a kind of precise and high efficiency, environmental protection.Concrete scheme is as follows:

1) invention of this technique is the foundation of carrying out adjust pH with methyl red indicator colour developing conduct, develops the color in the acid adjustment process, shows that the pH value is 5.6;

2) simultaneously, traditional technology is (crude product is ethanimidic acid methyl ether hydrochloride in the still) logical ammonia in trimethyl orthoacetate alcoholysis still, and the intake of ammonia is ethanimidic acid methyl ether hydrochloride: the mol ratio of ammonia is 1:(0.21)-(0.26); Technique after the improvement passes into ammonia in the cooling methyl alcohol, drips again, and the usage quantity of ammonia is: ethanimidic acid methyl ether hydrochloride: the mol ratio of ammonia is 1:(0.1)-(0.13);

3) before logical ammonia, it is in 20--10 ℃ the refrigerated methanol that ammonia is passed into temperature, passes to saturatedly, is added dropwise to the trimethyl orthoacetate in the reactor again.

Further, the temperature that passes in the refrigerated methanol of described ammonia is-10 ℃.

The invention has the advantages that:

13.3 gram: pH≤3.1(are red for tropeolin-D), pH3.1-4.4(is orange), pH 〉=4.4(is yellow);

Methyl red 13.3 gram: pH 5.2 (purple) → 5.4(ash is blue) → 5.6(is green);

Best pH is 5.6 during alcohol demodulation pH, and with the difficult control of tropeolin-D, and the colour developing of methyl red is more accurate.

During ventilation, ammonia is dissolved in the methyl alcohol, passes to saturatedly, be added dropwise to again reactor, with tradition directly ventilation enter in the alcoholysis still there to be advantage: reaction relaxes, and the rate of utilization of ammonia is higher, can not pollute environment.

Embodiment

Embodiment 1

1. in alcoholysis process,, in the acid adjustment process, develop the color, so that the pH value is controlled to be 5.6 optimum value as the foundation of carrying out adjust pH with the methyl red indicator colour developing;

2. ammonia is passed into respectively temperature and be in 20 ℃, 10 ℃, 0 ℃ ,-10 ℃ the refrigerated methanol, pass to saturated;

Pass into ammonia methyl alcohol in trimethyl orthoacetate alcoholysis still, the intake of ammonia is ethanimidic acid methyl ether hydrochloride: the mol ratio of ammonia is 1:(0.1)-(0.13), with the alcoholysis of ethanimidic acid methyl ether hydrochloride.

Simultaneous test:

Ammonia is the contrast of the solubleness under the differing temps in methyl alcohol:

。

As seen from the above table, the present invention uses and passes into ammonia under-10 ℃ of conditions to saturated, and as logical methanolic ammonia solution, effect is apparent in view, and suitable production requirement.

Claims

1. the alcoholysis process of a trimethyl orthoacetate is characterized in that:

The foundation of 1) transferring pH value with methyl red indicator colour developing conduct develops the color in the acid adjustment process, shows that pH value is 5.6;

2) simultaneously, directly lead to ammonia in trimethyl orthoacetate alcoholysis still (crude product is ethanimidic acid methyl ether hydrochloride in the still), the intake of ammonia is: ethanimidic acid methyl ether hydrochloride: the mol ratio of ammonia is 1:(0.21)-(0.26); Technique after the improvement passes into ammonia in the refrigerated methanol, drips again, and the usage quantity of ammonia is: ethanimidic acid methyl ether hydrochloride: the mol ratio of ammonia is 1:(0.1)-(0.13);

3) before logical ammonia, ammonia under the pressure of 1MPa, is passed into temperature and is in 20-10 ℃ the refrigerated methanol, pass to saturatedly, be added dropwise to again the trimethyl orthoacetate in the reactor.

2. the alcoholysis process of a kind of trimethyl orthoacetate according to claim 1, it is characterized in that: the temperature that described ammonia passes in the refrigerated methanol is-10 ℃.