CNS-active benzodiazepine derivs. - prepd. from a (2)-amino-(5)-chloro-(ortho)-halo-benzophenone

摘要

Benzodiazepines of formula (I) are prepd. from o-amino-benzophenones (II) by forming a diazepine ring between the amine and the ketone gps. and opt. replacing a hydrogen a atom by the gp. B2 (where R2 is H, allyl, propargyl, or -CONR5R6; R3 is 1-4C alkyl;R4 is Br, Cl or F; R5 is H or 1-4C alkyl; R6 is 1-4C alkyl). (I) are CNS active esp. in the treatment of anxiety, depression and anxiety neuroses. A typical cpd. is 7-chloro-3-ethoxycarbonyl-5-(2-fluorophenyl)-2-oxo-2, 3-dihydro 1H-1, 4-benzodiazepine. This was prepd. by treating 2-amino-5-chloro-2'-fluoro benzophenone with ethanolamine, and treatment of the prod. with ethyl aminomalonate hydrochloride. Finally the imine was cyclised by refluxing it in acetic acid.