Salt formation crystallization method of ethambutol hydrochloride

Abstract

The invention discloses a salt formation crystallization method of ethambutol hydrochloride. According to the salt formation crystallization method of ethambutol hydrochloride, the system temperature, the cooling rate and the falling temperature are strictly controlled during the salt formation, so that the purity of ethambutol hydrochloride can be increased, ethambutol hydrochloride meeting pharmacopeia standards can be produced through adopting ethambutol bulk drug with lower purity, and the higher yield is achieved. Through adoption of the salt formation crystallization method of ethambutol hydrochloride, an approach which is simple, convenient, and lower in cost is provided for synthesis of ethambutol hydrochloride.

Description

technical field [0001] The invention belongs to the field of preparation of anti-tuberculosis drugs, in particular to a salt-forming crystallization method of ethambutol hydrochloride. Background technique [0002] Ethambutol hydrochloride is an anti-tuberculosis drug. The drug has a strong inhibitory effect on Mycobacterium tuberculosis, but has no obvious effect on other bacteria, and has no cross-resistance with other anti-tuberculosis drugs. It is widely applicable to various types of tuberculosis and pulmonary tuberculosis. External tuberculosis. [0003] Ethambutol hydrochloride is a kind of hydrochloride of ethambutol dextrorotary form, which is prepared by salting ethambutol dextrorotary form and hydrochloric acid. The ethambutol molecule contains two chiral carbon atoms and has three optical isomers. The activity of the dextrorotary form against Mycobacterium tuberculosis is 12 times that of the mesoform, and 200-500 times that of the levorotatory form. Use its de...

AI Technical Summary

Problems solved by technology

The purity of ethambutol hydrochloride is greatly affected by the bulk drug, because in the salt-forming process, existing techniques are difficult to prevent impurities from entering the final product. Therefore, in the prior art, it is necessary to synthesize ethylamine hydrochloride that reaches the pharmacopoeia standard purity Butanol generally chooses two ways: one is to strictly purify the ethambutol raw material to make it more than 99% pure, and the hydrochloride prepared from such a raw material can generally have a purity of more than 99%, but such Purification is very difficult, especially when the purity of ethambutol is closer to 99%, the purification is more difficult, so the cost is extremely high; the second is to use general purity ethambutol to form a salt first, and then to obtain the salt after many times Repeated purification to make its purity reach 99%; no matter which method is used, it will greatly increase the production cost. At the same time, repeated purification will reduce the total yield of the reaction and inhibit the production capacity of the enterprise.

[0005] In the prior art, there is no easy and cheap ethambutol hydrochloride salt-forming crystallization method, so that the purity of ethambutol hydrochloride prepared by it can reach the standard of the Pharmacopoeia