Thionyl Chloride → 4-Bromo-2-Thiophenecarbonyl Chloride

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Reaction Steps

According to the procedure of Example 32, 2.48 g (12.0 mmoles) of 4-bromo-2-thiophenecarboxylic acid (prepared according to Lawesson, S. O., Arkiv. for Kemi. 11:317 (1957)) and 10 ml of thionyl chloride were combined and heated. The reaction gave 2.99 g of 4-bromo-2-thiophenecarbonyl chloride as a dark oil. Following the procedure of Example 32, the acid chloride, 2.11 g (10.0 mmoles) of 5-chloro-2-oxindole-1-carboxamide and 3.67 g (30.0 mmoles) of 4-(N,N-dimethylamino)pyridine were reacted in N,N-dimethyl-formamide to give 4.03 g of a crude orange solid. Recrystallization gave 2.67 g (6.68 mmoles, 66.8% yield) of title compound as a yellow crystalline solid, m.p. 217-219° C. (dec.) (2-butanone).

Provenance & Evidence