tert-Butanol → Methyl 6-[(tert-butoxycarbonyl)amino]-2-naphthoate

Beteiligte Stoffe

Reaktionsschritte

A suspension of 6-(methoxycarbonyl)-2-naphthoic acid [J. Med. Chem., 2004, 47, 303-324] (146) (1.21 g, 5.26 mmol) in dry t-BuOH (20 mL) containing powdered molecular sieves (1 g) was treated with Et3N (0.88 mL, 6.31 mmol) and stud under N2 at room temperature for 30 min. DPPA (1.25 mL, 5.80 mmol) was added and the mixture was sired at reflux for 7 h, then cooled and poured into dilute aqueous NaHCO3. The resting solid was purified by chromatography on silica gel, eluting with CH2Cl2, followed by trituration with iPr2O and recrystallization from EtOAc to give methyl 6-[(tert-butoxycarbonyl)amino]-2-naphthoate (147) (1.24 g, 78%) as a white solid: mp 178-180° C.; 1H NMR [(CD3)2SO] δ 9.76 (s, 1H), 8.51 (s, 1H), 8.19 (s, 1H), 8.02 (d, J=9.0 Hz, 1H), 7.90 (dd, J=8.6, 1.6 Hz, 1H), 7.86 (d, J=8.7 Hz, 1H), 7.59 (dd, J=8.9, 2.1 Hz, 1H), 3.89 (s, 3H), 1.52 (s, 9H). Anal. (C17H19NO4) C, H, N.

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