Zomebazam

Zomebazam produced by Hoechst is a pyrazolodiazepinone derivative drug with anxiolytic properties. It is structurally related to razobazam and zometapine.

The catalytic hydrogenation of N,2,5-trimethyl-4-phenyldiazenylpyrazol-3-amine (1) over Raney nickel gives 4-amino-1,3-dimethyl-5-methylaminopyrazole (2). Treatment with methyl malonyl chloride (3) gives 4-α-ethoxycarbonylacetylamino-1,3-dimethyl-5-methylaminopyrazole (4). Base-catalyzed lactamization gives (5). The Goldberg reaction completes the synthesis of zomebazam (6).