1,2-Dichloroethane → (+/-)-trans-7-acetylamino-3-bromo-3,4-dihydro-6-nitro-2,2-dimethyl-4-[(S)-(-)-3-acetylthio-2-methylpropionyloxy]-2H-1-benzopyran

Participants

Reaction Steps

To a mixture of (±)-trans-7-acetylamino-3-bromo-4-hydroxy-3,4-dihydro-6-nitro-2,2-dimethyl-2H-1-benzopyran, ethylene chloride and pyridine was added (S)-(-)-3-acetylthio-2-methylpropionyl chloride under ice-cooling over 5 minutes and stirred for 1.5 hours under room temperature. The reaction mixture was washed with diluted hydrochloric acid once and 10% aqueous sodium chloride solution twice. The organic layer was separated, dried over magnesium sulfate and concentrated under reduced pressure to give (±)-trans-7-acetylamino-3-bromo-3,4-dihydro-6-nitro-2,2-dimethyl-4-[(S)-(-)-3-acetylthio-2-methylpropionyloxy]-2H-1-benzopyran.

Provenance & Evidence