Hydrochloric Acid → [1-(3-Bromo-phenyl)-2,2-difluoro-1-hydroxymethyl-ethyl]-carbamic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

[1-(3-Bromo-phenyl)-1-difluoromethyl-allyl]-carbamic acid tert-butyl ester (7.88 g, 21.76 mmol) was dissolved in 218 ml dichloromethane and 73 ml methanol. NaHCO3 (2.74 g, 32.6 mmol) was added and the reaction mixture was cooled to −78° C. The solution was treated with O3 for 30 min. (until the reaction mixture turned blue). Gas was stopped and stirring was continued for 15 minutes. The reaction was flushed with oxygen and nitrogen until color disappeared. NaBH4 (2.47 g, 65.3 mmol) was added in three portions and stirring was continued for 30 min. at −78° C. The reaction was warmed to 0° C. and poured onto 435 ml 1 M HCl solution. The product was extracted with TBME. The organic phases were washed with water and brine, dried over Na2SO4 and concentrated under reduced pressure to yield the title compound as a greenish oil. 1H-NMR (600 MHz, DMSO-d6): 7.49 (m, 2H), 7.38 (br, 1H, NH), 7.32 (m, 2H), 6.37 (t, 1H, CHF2), 5.20 (br, 1H), 3.95 (m, 1H), 3.86 (br, 1H), 1.32 (s, 9H); MS: 366 [(M+H)+].

Provenance & Evidence