| 摘要 |
A process for the manufacture of a 5-cyano-4-lower alkyl-oxazole by the dehydration of a 5-carbamoyl-4-lower alkyl-oxazole comprises carrying out the dehydration with silicon tetrachloride in the presence of an amine in an organic solvent. The amine is suitably an aliphatic amine, especially a tertiary aliphatic amine, e.g. a trialkylamine, or a nitrogen-containing heteroaromatic compound, e.g. pyridine or a pyridine derivative. An aliphatic or cyclic ether, an aliphatic nitrile, an aromatic hydrocarbon or N-methylpyrrolidone is suitably used as the organic solvent. For example, 5-carbamoyl-4-methyl-oxazole is dehydrated by the process in accordance with the invention to 5-cyano-4-methyl-oxazole, which is a valuable intermediate in the synthesis of pyridoxine. |
