N-(2,4-dimethoxybenzyl)thiazol-2-amine → N-(2,4-Dimethoxybenzyl)-2-oxo-N-(thiazol-2-yl)-2,3-dihydrobenzo[d]oxazole-6-sulfonamide

Participants

Reaction Steps

A solution of 41-2 (2.79 g, 11.13 mmol) in THF (71 mL) was cooled to −78° C. Lithium hexamethyldisilizane (LHMDS, 21.4 ml, 21.4 mmol, 1.0M in THF) was added and the reaction was allowed to warm to RT and stir for 30 minutes. Commercially-available, solid 1-5 (4 g, 17.12 mmol) was then added in portions, maintaining the temperature of the reaction mixture at −78° C. The reaction was allowed to slowly warm to RT. After reaching RT, the reaction was quenched with saturated ammonium chloride solution at 0° C. and extracted into EtOAc (3×150 mL). The combined organic layers were washed with brine, dried over sodium sulfate, filtered and concentrated. Purification by normal phase chromatography (0-60% EtOAc in hexane) yielded 41-3 as a solid.

Provenance & Evidence