| 摘要 |
NEW MATERIAL:A 1-methyl-4-halogene-5-aminopyrazole shown by the formula I (X is halogen). EXAMPLE:1-Methyl-4-chloro-5-aminopyrazole. USE:An intermediate for dye, drugs, and agricultural chemicals (insecticide, fungicide, herbicide, or plant growth regulator). PREPARATION:beta-Cyanoethylhydrazine shown by the formula II is reacted with formalin or paraformaldehyde in the presence of a base to give formaldehyde-beta- cyanoethylhydrazine shown by the formula III in high yield and in high purity, then this compound is subjected to ring closure in the presence of a base to give 1-methyl-5-aminopyrazole shown by the formula IV in high yield from the inexpensive raw material. Then, this compound is reacted with chlorine, hypochlorous acid, bromine, or hypobromous acid, to give a compound shown by the formula I in high yield easily.
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