PROCESS FOR PRODUCTION OF MIRTAZAPINE

摘要

The invention provides a process for the production of mirtazapine by whi ch high-purity mirtazapine which is safely usable as drug can be simply and easily obtained from a reaction fluid obtained by ring-closing reaction of 2 -(4-methyl-2 -phenylpiperazin-1-yl)pyridine-3-methanol with concentrated sul furic acid. A process for the production of mirtazapine, characterized by su bjecting a reaction fluid obtained by ring-closing reaction of 2-(4-methyl-2 -phenylpiperazin -1-yl)pyridine-3-methanol with concentrated sulfuric acid t o dilution with water, alkalizing the obtained dilution in the presence of p ropanol to extract mirtazapine into the propanol, and crystallizing mirtazap ine from the resulting extract.