N-bromobutanimide → Methyl 2-[(tert-butoxycarbonyl)amino]-1-bromo-6-naphthoate

Participants

Reaction Steps

A mixture of ester 147 (977 mg, 3.24 mmol) and NBS (664 mg, 3.73 mmol) in CH3CN (25 mL) was stirred at reflux for 45 min, then concentrated under reduced pressure. The residue was dissolved in CH2Cl2 and the solution was washed with 10% aqueous Na2SO3 and water (×2), dried, and concentrated under reduced pressure. The residue was purified by chromatography on silica gel, eluting with CH2Cl2, to give methyl 2-[(tert-butoxycarbonyl)amino]-1-bromo-6-naphthoate (148) (1.12 g, 91%) as a white solid: mp (petroleum ether) 130-131° C.; 1H NMR [(CD3)2SO] δ 8.93 (s, 1H), 8.65 (d, J=1.6 Hz, 1H), 8.64 (d, J=8.9 Hz, 1H), 8.16 (d, J=8.9 Hz, 1H), 8.11 (dd, J=8.9, 1.7 Hz, 1H), 7.86 (d, J=8.9 Hz, 1H), 3.93 (s, 3H), 1.50 (s, 9H). Anal. (C17H18BrNO4) C, H, N, Br.

Provenance & Evidence