Pyrrolidine → tert-Butyl 6-bromo-4-oxo-3,4-dihydro-1'H-spiro[1,3-benzoxazine-2,4'-piperidine]-1'-carboxylate

Participants

Reaction Conditions

Reaction Steps

Three batches of 5-bromo salicylamide (5.00 g each, 23.1 mmol), N-Boc-piperidin-4-one (3.45 g, 17.3 mmol) and pyrrolidine (1.64 g, 23.1 mmol) were heated in different flasks at 72° C. under MW irradiation for 1 h. Further N-Boc-piperidin-4-one (3.45 g, 17.3 mmol) was added and the mixtures were heated for 1 h at 72° C. The resulting precipitates were collected by filtration and washed with MeOH to give 6-bromo-3,4-dihydro-4-oxo-spiro[2H-(1,3)-benzoxazine-2,4′-piperidin]-1′-carboxylic acid tert-butyl ester (17.2 g) as a white solid.

Provenance & Evidence