Trimethyl orthoacetate → 1,1-dimethylethyl 10-bromo-2-methyl-6,7,8,9-tetrahydro-5H-[1,3]oxazolo[4,5-h][3]benzazepine-7-carboxylate

Participants

Reaction Steps

1,1-Dimethylethyl 8-amino-6-bromo-7-hydroxy-1,2,4,5-tetrahydro-3H-3-benzazepine-3-carboxylate (1.604 g) was treated with trimethyl orthoacetate (0.856 ml) and pyridinium p-toluenesulfonate (112 mg) in dry DMF (23 ml) at 60° C. for 1.5 hours. Volatiles were evaporated under reduced pressure and the residue was purified on silica gel (ethyl acetate/petroleum ether: 1/6) providing the title compound as white solid (1.553 g, 90% yield).

Provenance & Evidence