Ammonium Acetate → HCID 57816628, compound

Participants

Reaction Conditions

Reaction Steps

A mixture of (2S)-tert-butyl 2-(7-bromo-4-oxochroman-3-ylcarbamoyl)pyrrolidine-1-carboxylate (3.23 g, 7.35 mmol) and ammonium acetate (5.6 g, 73.5 mmol) in xylenes (40 mL) was heated at 130° C. for 2 hours. The reaction was cooled to room temperature. The xylenes were removed under reduced pressure and the residue was diluted with dichloromethane (100 mL). Saturated sodium bicarbonate (200 mL) was added slowly with stirring until gas evolution had subsided. The phases were separated and the aqueous phase was extracted with dichloromethane (50 mL). The combined organic phases were washed with brine (50 mL) and dried over sodium sulfate. The mixture was filtered and the solvent was removed under reduced pressure. The residue was subjected to flash chromatography with eluant of (10% methanol in ethylacetate) and hexane. The product containing fractions were combined and the solvent was removed under reduced pressure to provide (S)-tert-butyl 2-(7-bromo-3,4-dihydrochromeno[4,3-d]imidazol-2-yl)pyrrolidine-1-carboxylate (1.77 g, 4.21 mmol, 57%).

Provenance & Evidence