Hydrogen Bromide → methyl 2-((S)-1-amino-2-methylpropyl)-5-(7-bromo-1H-indol-3-yl)oxazole-4-carboxylate hydrobromide

Participants

Reaction Conditions

Reaction Steps

Glacial acetic acid (25 mL) was added to methyl 2-((S)-1-(benzyloxycarbonylamino)-2-methylpropyl)-5-(7-bromo-1H-indol-3-yl)oxazole-4-carboxylate (9.99 g, 19.0 mmol) in a 500-mL round-bottom flask fitted with a mechanical stirrer. The suspension was stirred at 25° C. and 33% HBr in acetic acid (50 mL) was added in one portion. The mixture became homogeneous and then a precipitate formed in 5-10 min. After 1 h, MTBE (235 mL) was added and stirring was continued at 25° C. for another 1 h 20 min. The mixture was filtered and the precipitate was washed with MTBE (150 mL). The cream-colored powder was dried under vacuum to give methyl 2-((S)-1-amino-2-methylpropyl)-5-(7-bromo-1H-indol-3-yl)oxazole-4-carboxylate hydrobromide (8.91 g, 99% yield). 1H NMR (300 MHz, DMSO-d6): consistent with proposed structure. MS: m/z=392.0 (M+1).

Provenance & Evidence