PRODUCTION OF 2-METHOXYMETHYLENE-3,3-DIMETHOXYPROPANENITRILE

摘要

PURPOSE:To obtain a compound useful as an intermediate for synthesizing vitamin B1 or such in high yield, by reacting a nitrile compound with an acid in methanol. CONSTITUTION:A nitrile compound shown by the formula (R is lower alkyl; M is alkali metal) is racted with an excess of an acid in methanol at 30-60 deg.C to give the aimed substance. A Brphinsted acid (e.g. conc. sulfuric acid) or Brphinstead acid and a Lewis acid are used as the acid and are added once or act at two stages dividedly. Dehydrated methanol having <=500ppm, especially <=100ppm water content is preferably used as the methanol and the amount of the methanol used is an amount to make 5-20wt% raw material compound. The aimed substance can be directly subjected to ring closure reaction without requiring separating operation.