IMPROVED METHOD OF MAKING NEVIRAPINE

摘要

A process for making nevirapine, comprising the following steps: (a) reacting a 2-halo-3-pyridinecarbonitrile of the formula (I), wherein X is a fluorine, chlorine, bromine or iodine atom, preferably chlorine or bromine, with cyclopropylamine, to yield 2-(cyclopropylamino)-3-pyridinecarbonitrile; (b) hydrolyzing the 2-(cyclopropylamino)-3-pyridinecarbonitrile to yield 2-(cyclopropylamino)-3-pyridine carboxylic acid; (c) isolating the 2-(cyclopropylamino)-3-pyridine carboxylic acid from the reaction medium; (e) treating the 2-(cyclopropylamino)-3-pyridine carboxylic acid with a chlorinating agent, to yield 2-(cyclopropylamino)-3-pyridinecarbonyl chloride; (f) reacting the 2-(cyclopropylamino)-3-pyridine carbonyl chloride with a 2-halo-4-methyl-3-pyridinamine of the formula (I), wherein X is a fluorine, chlorine, bromine or iodine atom, preferably chlorine or bromine, to produe an N-(2-halo-4-methyl-3-pyridinyl)-2-(cyclopropylamino)-3-pyridinecarboxamide; and (g) cyclizing the N-(2-halo-4-methyl-3-pyridinyl)-2-(cyclopropylamino)-3-pyridinecarboxamide by treatment with a strong base, to yield nevirapine.