Diels-Alder reactions with 2-methylpyridazin-3(2H)-ones bearing electron-withdrawing substituents at the 4- or 5-position
作者:Francisco Fariña、M. Victoria Martín、Magali Romañach
DOI:10.1016/s0040-4020(01)90427-2
日期:1994.4
Diels-Alder reactions of 2-methylpyridazin-3(2H)-ones, substituted with ethylsulphonyl, cyano and methoxycarbonyl groups at the 4- or 5-positions, with 1,3-dienes have been investigated. Pyridazinones behave as poor dienophiles and their reactivity depends on the nature and position of the substituents. 5-Substituted pyridazinones are more reactive than the 4-substituted isomers and high conversions