85057-78-9Relevant articles and documents
ELECTROPHILIC HETEROAROMATIC SUBSTITUTIONS. X. UNEXPECTED RESULTS IN THE α-SIDE-CHAIN CHLORINATION OF A SERIES OF ETHYL 3,4,5-TRIALKYLPYRROLE-2-CARBOXYLATES
Scarsella, Marco,Sleiter, Giancarlo
, p. 757 - 762 (2007/10/02)
The reaction of a series of 3,4,5-trialkyl-substituted ethyl pyrrole-2-carboxylates with an excess of sulphuryl chloride followed by solvolysis has been investigated in several solvents and under different experimental conditions.In all cases, beside the expected α-side-chain substituted product, substantial amounts of derivatives functionalised also in a β-side chain have been isolated and identified.The process turned out to be electrophilic in nature and to involve allylic migration of the halogen from the α-sigma adduct to the adjacent β-side chain.Virtually identical results have been obtained when elemental chlorine was used.