Acetic Acid → HCID 178448378, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of Boc-NVA-OH (4.5 g, 21 mmol) in acetonitrile (68 mL) and 4-methylmorpholine (2.41 mL, 21.9 mmol) cooled to −20° C. was added isobutyl chloroformate (2.7 mL, 21 mmol) dropwise. The mixture was stirred for 120 minutes at −20° C. and then 4-bromo-1,2-benzenediamine (3.87 g, 20.7 mmol) was added. The reaction mixture was allowed to warm to room temperature and stirred for 18 hours. The solvent was evaporated, redissolved in ethyl acetate, washed with water, saturated aqueous solution of sodium hydrogen carbonate, and brine. The organic layer was dried over anhydrous magnesium sulfate, filtered, and concentrated in vacuo. The resulting residue was dissolved in acetic acid (20 mL, 400 mmol) and stirred at 70° C. for 6 hours. The acetic acid was removed in vacuo and the mixture was redissolved in ethyl acetate, washed with saturated aqueous solution of sodium hydrogen carbonate, and brine. The organic layer was dried over anhydrous magnesium sulfate, filtered, and concentrated in vacuo. The resulting oil was redissolved in dichloromethane, treated with activated carbon and filtered through a plug of celite. Purification by silica gel column chromatography eluting with a 0-100% ethyl acetate/hexanes gradient to afford the title compound (5.95 g, 78%) as a white solid.

Provenance & Evidence