Patent ID: 7102010

Claim:
A process for the preparation of a 5-substituted oxazole or 5-substituted imidazole comprising synthesizing p-tolylsulfonylmethylisocyanide from N-(p-tolylsulfonylmethyl)formamide with phosphorus oxychloride, phosgene or diphosgene, and a tertiary amine, to form a p-tolylsulfonylmethylisocyanide solution which is not isolated and purified as crystals, and reacting the p-tolylsulfonylmethylisocyanide solution with an aldehyde or a compound represented by Formula (I): R 1 CH═NR 2 wherein, R 1 and R 2 are optionally substituted phenyl, optionally substituted heterocyclic group or optionally substituted alkyl, wherein the p-tolylsulfonylmethylisocyanide solution is reacted with an aldehyde or a compound of Formula (I) in a mixed solvent of an aprotic solvent and a protic solvent in the presence of potassium hydroxide or sodium hydroxide or mixtures thereof.