tert-Butanol → 1H-Pyrrolo[2,3-b]pyridine-4-carboxylic acid,1,1-dimethylethyl ester

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Reaction Steps

A stirred suspension of 1H-pyrrolo[2,3-b]pyridine-4 carboxylic acid (0.2 g, reference Example 69) in dry dimethylformamide (5 mL), under nitrogen, was treated with 1,1′-carbonyldiimidazole (0.2 g). After stirring at room temperature for 1 hour the resulting tan coloured solution was treated with tert-butanol (260 μL) and DBU (203 μL). This mixture was stirred at 40° C. overnight then evaporated. The residue was partitioned between water (30 mL) and ethyl acetate (30 mL) and the aqueous layer was then extracted twice with ethyl acetate (10 mL). The combined organics were washed twice with brine (10 mL), then dried over sodium sulfate and then evaporated to give the title compound (0.21 g) as a yellow solid.

Provenance & Evidence