Polyhalogenoheterocyclic compounds. Part XXVIII. Polychloroindoles

Abstract

5,7-Di-, 5,6,7-tri-(3), and 3,5,6,7-tetra-chloroindoles have been characterised on the basis of ¹H coupling constants. Further chlorination of compound (3), with phosphorus pentachloride, gave 2,3,3,4,5,6,7-heptachloro-3H-indole (5), characterised with the aid of ¹³C n.m.r., and identical with a sample prepared by pyrolysis of N-penta-chlorophenyltrichloroacetimidoyl chloride (7). Compound (5) reacted with sodium isopropoxide or amines to give substitution products, whereas with sodiomalonic ester or sodium benzenethiolate products were obtained which indicate that initial attack takes place on chlorine.