CARBAMATE OXIME REDUCTION - A NEW ROUTE TO C3-AMINO-1,4-BENZODIAZEPINES

A mild reduction method of C3-oximido-1,4-benzodiazepines to afford th e C3-amino derivatives is described. The key step involves the formati on of a carbamate oxime intermediate. The greater reactivity of the C3 -(ethylaminocarbonyl)oximido-1,4-benzodiazepine towards hydrogenation, compared to the parent C3-oxime, enables the reduction to take place at ambient temperature using palladium-on-carbon. The mild conditions are more suitable for sensitive amines such as 3,5-diamino-1,4-benzodi azepines.