Citric Acid → {2-[(5-Vinyl-benzofuran-2-carbonyl)-amino]-phenyl}-carbamic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

To a mixture of 2027 mg (4.7 mmol) {2-[(5-Bromo-benzofuran-2-carbonyl)-amino]-phenyl}-carbamic acid tert-butyl ester (56) and 289 mg (0.25 mmol) Pd(Ph3)4 in 40 ml toluene were added 1.84 ml of a 5.4M solution of sodium methoxide in methanol and 957 mg (5.2 mmol) vinylboronic acid dibutyl ester and the solution was heated at 90° C. for 3 h. The reaction mixture was poured on 5% aqueous citric acid. Extraction with ethyl acetate, washing of the organic phase with brine. The organic phase was dried over sodium sulfate, the solvent was evaporated and the residue subjected to silica gel chromatography (petrolether/ethylacetate 2:1) to give 1530 mg (4.04 mmol) {2-[(5-Vinyl-benzofuran-2-carbonyl)-amino]-phenyl}-carbamic acid tert-butyl ester (57).

Provenance & Evidence