Citric Acid → HCID 69489781, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of 96 mg (0.25 mmol) {2-[(5-Hydroxy-benzo[b]thiophene-2-carbonyl)-amino]-phenyl}-carbamic acid tert-butyl ester (4) in 5 ml acetonitrile was added 120 mg potassium carbonate and 0.3 ml (2-bromoethoxy)-tert-butyldimethylsilane. The reaction mixture was heated at reflux for 90 min and at 85° C. for 2 h and poured into 5% aqueous citric acid. The aqueous phase was extracted with ethyl acetate and the organic phase was dried over sodium sulfate, the solvent was evaporated and the residue subjected to silica gel chromatography (petrolether/ethylacetate 4:1 and then 9:1). [2-({5-[2-(tert-Butyl-dimethyl-silanyloxy)-ethoxy]-benzo[b]thiophene-2-carbonyl}-amino)-phenyl]-carbamic acid tert-butyl ester (40) (63 mg, 0.116 mmol) was obtained as a colorless solid.

Provenance & Evidence