3-Hydroxypyrroles and 1H-pyrrol-3(2H)-ones. Part 8. Reactions of 1-isopropyl-2,2-dimethyl-1H-pyrrol-3(2H)-one with electrophiles
Abstract
Reaction of the pyrrolone (2) with N-, C-, and halogen-electrophiles takes place at the 4-position to give the azo compounds (3)–(5), the ‘methylene Meldrum’s′ derivative (12) and the halogeno derivatives (16)–(18). Reductive cleavage of the azo compound (5) gives a convenient route to the 4-aminopyrrolone (7), which may be diazotised and coupled with 2-naphthol. Decomposition of the Meldrum's derivative (12) with base leads to the malonates (13) and (14) and acrylate (15). Deuterium exchange at the 5-position takes place when the halogeno compounds (16)–(18) are treated with [2H3]methoxide in [2H4]methanol: the 5-anion is thought to be an intermediate. Protodehalogenation of the 4-bromo- and 4-iodo-derivatives (17) and (18) occurs on treatment with triphenylphosphine.
Please wait while we load your content...
