m-Chloroperbenzoic acid → 3-(5-Bromo-2-hydroxy-phenoxy)-azetidine-1-carboxylic acid tert-butyl ester

Participants

Reaction Steps

To a CH2Cl2 (280 mL) solution of the title compound of Step B (24.7 g, 69.4 mmol) was added 77% m-CPBA (23.3 g, 104 mmol). After 15 h, 10% Na2S2O5 (aq.) was added and the solution allowed to stir until the aqueous was KI paper negative then extracted with CH2Cl2 (2×). The combined organic layers were washed with saturated NaHCO3 (aq.), concentrated and treated with MeOH (220 mL) and 1N NaOH (220 mL). After 15 h, the reaction was partially concentrated to remove the MeOH, acidified with 1M KHSO4 (220 mL) and extracted with CH2Cl2 (2×). The combined organic layers were washed with brine and dried providing a brown solid that was triturated with EtOAc/hexanes giving 17.6 g (74%) of the title compound as a white solid. 1H NMR (CDCl3): 7.03 (dd, J=8.5, 2.1 Hz, 1H), 6.84 (d, J=8.5 Hz, 1H), 6.64 (d, J=2.2 Hz, 1H), 4.93-4.89 (m, 1H), 4.34 (dd, J=10.1, 6.8 Hz, 1H), 4.03 (dd, J=9.9, 3.7 Hz, 1H), 1.46 (s, 9H).

Provenance & Evidence