摘要:
A practical and Scalable process for the preparation of 4-amino-1,3-dimethylpyrazole hydrochloride I is described. Compound I is a useful starting material; its preparation is achieved ilia a three-step sequence from methyl hydrazine and technical grade acetaldehyde dimethylacetal. The target molecule is isolated in high chemical and isomeric purity (>99.0% with respect to 4-amino-1,5-dimethylpyrazole.