NBS or DEAD as effective reagents in α-thiocyanation of enolizable ketones with ammonium thiocyanate

Ketones possessing α-hydrogen undergo smooth thiocyanation with ammonium thiocyanate in the presence of N-bromosuccinimide (NBS) at room temperature in acetonitrile under neutral conditions to produce the corresponding α-ketothiocyanates in excellent yields with high selectivity. The use of NBS makes this procedure simple, convenient and cost effective. In addition, diethyl azodicarboxylate (DEAD) was also found to promote this reaction under mild conditions.