Sodium Hydroxide → 5-Iodo-1-benzothiophene-2-carboxylic acid

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Reaction Steps

Sodium hydroxide (5 g) in water (150 ml) was added to ethyl 5-iodobenzo[b]thiophene-2-carboxylate (14 g) in ethanol (200 ml) and the mixture was stirred for 16 hours. The mixture was concentrated to about 150 ml by evaporation and the mixture was adjusted to ~pH 3 by addition of dilute hydrochloric acid. The mixture was then extracted with diethyl ether (2×100 ml). The combined organic extracts were dried (MgSO4) and evaporated to give 5-iodobenzo[b]thiophene-2-carboxylic acid (11.7 g) as a solid; NMR (d6 -DMSO): 7.8 (dd, 1H), 7.9 (d, 1H), 8.05 (s, 1H), 8.45 (d, 1H).

Provenance & Evidence