Methyl N-(triethylammoniosulfonyl)carbamate → tert-butyl 4-[(4S)-4-(methoxycarbonyl)-4,5-dihydro-1,3-oxazol-2-yl]-1H-indole-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of tert-butyl 4-({[(1S)-1-(hydroxymethyl)-2-methoxy-2-oxoethyl]amino}carbonyl)-1H-indole-1-carboxylate (2.09 g) in THF (21.0 mL) was added Burgess Reagent (1.44 g) at ambient temperature and the mixture was stirred at 70° C. for 45 minutes. The resulting mixture was diluted with EtOAc (60 mL) and washed successively with saturated NaHCO3 aqueous solution and brine. The organic layer was dried over anhydrous MgSO4, filtered and evaporated in vacuo. The residue was purified by silica gel column chromatography (n-hexane:EtOAc=2:1) to afford tert-butyl 4-[(4S)-4-(methoxycarbonyl)-4,5-dihydro-1,3-oxazol-2-yl]-1H-indole-1-carboxylate (1.35 g) as a colorless amorphous.

Provenance & Evidence