申请人:American Cyanamid Company
公开号:US04014896A1
公开(公告)日:1977-03-29
There is provided a process for the preparation of 3,5-disubstituted pyrazoles which involves: A. the reaction of a methyl ketone, such as acetophenone or an appropriate derivative thereof, with an appropriate aldehyde, such as benzaldehyde in the presence of base to form a 1,3-disubstituted .alpha.,.beta.-unsaturated ketone, such as chalcone or a substituted chalcone, B. the acidification of said .alpha.,.beta.-unsaturated ketone, followed by treatment of the acidified reaction mixture with hydrazine to form a disubstituted pyrazoline, and C. the catalytic dehydrogenation of said pyrazoline to yield the desired 3,5-disubstituted pyrazole.
提供了一种制备3,5-二取代吡唑的方法,其中包括:A.在碱存在下,将甲基酮(例如苯乙酮或适当的衍生物)与适当的醛(例如苯甲醛)反应,形成1,3-二取代的α,β-不饱和酮(例如查尔酮或取代查尔酮);B.酸化所述α,β-不饱和酮,然后用肼处理酸化的反应混合物,形成二取代吡唑;C.催化脱氢所述吡唑,得到所需的3,5-二取代吡唑。