Process Intensification and Integration Studies for the Generation of a Key Aminoimidazole Intermediate in the Synthesis of Lanabecestat

Homo-condensation of acetophenones toward imidazothiones

Direct synthesis of imidazothiones from simple, commercial substrates is not known. We report a method for the condensation of acetophenones, elemental sulfur, and ammonium acetate as a nitrogen source to obtain the hitherto challenging five-membered heterocycles. Functionalities such as halogen, trifluoromethyl, cyano, methylthio, and heteroaryl groups were well tolerated.

Synthesis of imidazothiones from acetophenones is reported for the first time. The use of a wide range of functionalities and heterocycles was well tolerated.