2-Bromo-4-fluorobenzene-1-sulfonyl chloride → methyl (R)-7-(2-bromo-4-fluorobenzenesulfonylamino]-2,3,3a,4-tetrahydro-1H-benzo[b]pyrrolo[1,2-d][1,4]oxazine-6-carboxylate

Participants

Reaction Steps

2-Bromo-4-fluorobenzenesulfonyl chloride (0.656 g) was added to a solution of methyl (R)-7-amino-2,3,3a,4-tetrahydro-1H-benzo[b]pyrrolo[1,2-d][1,4]oxazine-6-carboxylate (Intermediate 6, 0.525 g) in pyridine (10 mL) and DCM (10 mL) and the mixture was stirred at room temperature overnight. The mixture was concentrated in vacuo and the residue was partitioned between ethyl acetate and 0.5M hydrochloric acid solution. The organic layer was dried (Na2SO4), filtered and the filtrate was concentrated in vacuo. The residue was purified by chromatography on silica, eluting with a mixture of ethyl acetate and cyclohexane with a gradient of 0-40% to give a pale yellow solid which was triturated with ether and cyclohexane (1:2) to give methyl (R)-7-(2-bromo-4-fluorobenzenesulfonylamino]-2,3,3a,4-tetrahydro-1H-benzo[b]pyrrolo[1,2-d][1,4]oxazine-6-carboxylate (0.820 g).

Provenance & Evidence