Cyanogen Bromide → (R)-4-(6-Bromo-3-fluoro-pyridin-2-yl)-5,5-difluoro-4,6,6-trimethyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine

Participants

Reaction Conditions

Reaction Steps

A solution of (R)-2-methyl-propane-2-sulfinic acid [(R)-1-(6-bromo-3-fluoro-pyridin-2-yl)-2,2-difluoro-3-hydroxy-1,3-dimethyl-butyl]-amide (2.95 g, 6.84 mmol) and cyanogen bromide (2.24 g, 20.52 mmol) in dry ethanol (68 ml) was sealed with a glass stopper and heated at 85° C. for 9 hr. The reaction solution was evaporated in vacuo and the crude product was taken up with ethyl acetate and 2M aq. ammonia. The organic phase was washed with water and brine, dried over sodium sulfate, filtered and evaporated. The crude product (2.74 g) was chromatographed over silica gel (toluene/ethyl acetate 6:4) to give the title compound as a colourless solid. 1.19 g (48.9% yield).

Provenance & Evidence