Citric Acid → HCID 73013559, compound

Participants

Reaction Steps

To a solution of 1.0 g (2.93 mmol) 6-chloro-5-hydroxy-pyrrolo[2,3-b]pyridine-1,2-dicarboxylic acid 1-tert-butyl ester 2-ethyl ester in 20 mL N,N-dimethylformamide was added 0.14 g (3.23 mmol) sodium hydride (60% dispersion in mineral oil). After 30 min., 0.44 mL (0.64 g, 5.87 mmol) ethyl bromide was added and the suspension stirred for 1 h. The reaction mixture was poured into 10% aqueous citric acid solution and extracted twice with ethyl acetate. The combined organic phases were washed with brine, dried over magnesium sulfate, filtered and evaporated. The residue was purified by column chromatography over silica gel (0.030–0.063 mm) with ethyl acetate:n-hexane (1:2) as eluant to give the product as a colourless crystalline solid (93.4%).

Provenance & Evidence