Egis Gyogyszergyar Rt.

Csilla Kiss

Imre Moravcsik

Antal Simay

Gyula Horvath

Tamas Hamori

Tibor Balogh

Jeno Korosi

Peter Botka

Gyorgy Somogyi

Erno Orban

Maria Bidlo Nee Igloi

Nee Dievald Uskert

Roozsa Gyenge

The invention relates to a process for the preparation of 1-(3-chlorophenyl)-4-methyl-7,8-dimethoxy-5 H-2,3-benzodiazepine of formula (I) ##STR1## in high purity and in a quality suitable for pharmaceutical purposes. According to the invention the reaction of 1 mole of 2-acetonyl-3'-chloro-4,5-dimethoxybenzophenone of formula (II) ##STR2## with 3-7 moles of hydrazine hydrate in an organic solvent or in a mixture of organic solvents at a temperature between 15.degree. C. and 85.degree. C. is carried out in the absence of air oxygen, optionally in the presence of water. The crude product is then recrystallized from an aliphatic alcohol containing 1 to 5 carbon atom(s).

Process for the preparation of high-purity

Growing community of inventors

Budapest, Hungary

Csilla Kiss