Sodium hydride → HCID 54689835, compound

Participants

Reaction Steps

To a solution of 4.42 g (9.45 mmol) of 4-(4-benzyloxy-phenyl)-2-(2-ethoxycarbonyl-acetylamino)-thiophene-3-carboxylic acid ethyl ester from Example 7c in 50 mL of THF was added 1.6 g (40 mmol) of 60% NaH in mineral oil. The mixture was stirred at reflux under N2 for 17 h, then the excess NaH was quenched by the addition of 25 mL H2O. The reaction was concentrated in vacuo to remove most of the THF, then the remaining mixture was taken up in 75 mL of 2M NaOH and 75 mL of ethanol and heated at reflux for 6.5 h. The ethanol was removed in vacuo, and the aqueous solution was diluted with water to a total volume of 150 mL. The solution was extracted with diethyl ether (3×30 mL) to remove the mineral oil, then the aqueous layer was filtered through diatomaceous earth to remove some cloudiness. The solution was made acidic by addition of 80 mL of 4M HCl, and filtered after bubbling had ceased (about 5 min). The precipitate was washed with water, then dried on the filter to give 2.55 g (77%) of a tan solid as the titled compound. MS (ESI) m/e 350, (M+H)+; 1H NMR (300 MHz, DMSO-d6) δ 5.13 (s, 2H) 5.70 (s, 1H) 6.92 (s, 1H) 6.98 (m, 2H) 7.40 (m, 7H) 10.82 (s, 1H).

Provenance & Evidence