2,6-二取代苯乙酮苯腙在多聚磷酸(PPA)存在下的成环反应

Cyclizations of 2, 6-Disubstituted Acetophenone Phenylhydrazones in the Presence of Polyphosphoric Acid

Fischer反应是合成吲哚最常用的方法之一。我们用2,4,6-三甲氧基苯乙酮苯腙在PPA存在下成环时,只得到了少量的的2-(2,4,6-三甲氧基苯基)吲哚,而主要产物则为4,6-二甲氧基-3一甲基-1-苯基吲唑。

In the presence of PPA, cyclization of a series of 2,6-disubstituted acetophenonephenylhydrazones gives, in addition to the conventional 2-arylindoles, the indazoles formedby elimination of the 2- or 6-substituent.