Shiv P. Singh and Dalip Kumar
Treatment of substituted hydrazines (2a–d) with 3-acetyl-4-ethoxy-1,1,1-trifluorobut-3-en-2-one (1) yields the title compounds (3a–d) whereas methylhydrazine on similar treatment gives 4-acetyl-1-methyl-3-trifluoromethylpyrazole (3e).