Optimisation of substitution at the 2-and 5-positions of 3, 4-dialkoxythiophenes via the Mannich reaction: the influences of steric crowding, electrophile reactivity and …

J Halfpenny, PB Rooney, ZS Sloman

Index: Halfpenny; Rooney; Sloman Journal of the Chemical Society. Perkin Transactions 1, 2001 , # 20 p. 2595 - 2603

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Citation Number: 20

Abstract

A number of 3, 4-dialkoxythiophene compounds have been synthesised and their reactivities assessed via the Mannich reaction with secondary amines. These reactions surprisingly gave the bis-Mannich bases substituted at the 2-and 5-positions as well as the expected mono-Mannich bases substituted at the 2-position. Conditions were optimised to give symmetrical bis-2, 5-Mannich bases in one step and asymmetrical bis-2, 5-Mannich ...