β-unsaturated ketones were prepared. Upon addition of hydrazine, followed by iodination, 4-iodinated 3-methoxypyrazoles were obtained. The occurrence of a side compound also provided insights in the scope of this synthesis. In a second part, 1-(4-chlorophenyl)-3,3-dimethoxyprop-2-en-1-one was obtained from 1,1-dimethoxyethene and 4-chlorobenzoylchloride. The subsequent addition of hydrazine or phenylhydrazine
通过
1,1-二甲氧基乙烯与酸酐的缩合反应,可制得合成上有用的β,β-二甲氧基-α,β-不饱和酮。加入
肼后,进行
碘化,得到4-
碘化的3-甲氧基
吡唑。副化合物的出现也为该合成的范围提供了见识。在第二部分中,从1,1-二甲氧基
乙烯和
4-氯苯甲酰氯获得1-(4-
氯苯基)-3,3-二甲氧基丙-2-烯-1-酮。随后加入
肼或苯
肼得到5-(4-
氯苯基)-3-甲氧基-1 H-
吡唑或1-苯基-5-(4-
氯苯基)-3-甲氧基
吡唑,空前的总收率为64或54%。出乎意料的是,加入2-
吡啶肼导致了2-([1,2,4]三唑并[4,3-a]
吡啶-3-基)-1-(4-
氯苯基)乙酮。这导致我们设计了原始条件,从而以39%的总收率得到了目标1-(2-
吡啶基)-5-(4-
氯苯基)-3-甲氧基
吡唑。从各种羧
氯化物开始,提供了另外的实例。