The present invention relates to the process for the preparation of 1-(3,4-dimethoxy-phenyl)-5-ethyl-7,8-dimethoxy-4-methyl-5H-2,3-benzodiazepine of the Formula (I) by reacting 3,4,3',4'-tetramethoxy-6-(α-aceto-propyl)-benzofenon of the general Formula (II) with hydrazine or hydrazine-hydrate in alcoholic medium, and isolating and purifying the reaction product with a clarifier, which comprises using during the clarifying step a recrystallization solution having an iron content lower than 7 ppm.
本发明涉及通过在醇性介质中将通用式(II)的3,4,3',4'-四甲氧基-6-(α-乙酰基丙基)-苯并酮与
肼或
肼水合物反应,然后利用澄清剂分离和纯化反应产物,制备通式(I)的1-(3,4-二
甲氧基苯基)-5-乙基-7,8-二甲氧基-4-甲基-5H-2,3-苯二氮杂
环己烷的过程,其中在澄清步骤中使用的再结晶溶液的
铁含量低于7 ppm。