Lotrifen

Lotrifen (INN), also known as trazisoquine and sold under the brand names Canocenta and Privaprol, is an abortifacient which is used in veterinary medicine. It was described in 1978.

Synthesis

 * Lotrifen synthesis.svg

Reaction of the acyl hydrazide (1) and the carboximidate (2) gives compound (3). Heating this in the presence of sodium hydride cyclises this intermediate, forming the 1,2,4-triazole ring system of the drug. Oxidation of (4) with N-bromoacetamide yields lotrifen.