摘要 |
3,4-Diaryl-4,5-dihydro-1H-pyrazole compounds having a selected 5- or 6-membered aromatic heterocyclic moiety in the 4-position and an optionally substituted phenyl moiety in the 3-position, such as 4,5-dihydro-3-(4-fluorophenyl)-4-(5-trifluoromethyl-2-pyridinyl)-1H-pyrazole were prepared as intermediates in the preparation of insecticidal 3,4,N-triaryl-4,5-dihydro-1H-pyrazole-1-carboxamide compounds. The 3,4-diaryl-4,5-dihydro-1H-pyrazole compounds can be prepared from appropriate 1,2-diarylethanone compounds by successive treatments with N,N,N',N'-tetramethyldiaminomethane in dichloromethane in the presence of acetic anhydride (to form a Mannich adduct) and hydrazine in the presence of a catalytic amount of trifluoroacetic acid.
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