反应详情

Step 2 A mixture of racemic benzyl 1-(3-bromo-2-methylphenylamino)-4-(methylthio)-1-oxobutan-2-ylcarbamate (1.31 g, 2.90 mmol) and DCM (4 mL) was diluted with iodomethane (7.5 mL, 120 mmol) and the mixture was stirred at rt. After 24.5 h, the mixture (a solution with an insoluble reddish oil) was concentrated under vacuum. The residue was treated three times with DCM and concentrated under vacuum to provide racemic (3-(benzyloxycarbonylamino)-4-(3-bromo-2-methylphenylamino)-4-oxobutyl)dimethylsulfonium iodide as an orange-yellow glassy foam (1.75 g, 97%). 1H NMR (400 MHz, chloroform-d) 69.16 (1H, br. s.), 7.28-7.46 (7H, m), 6.99 (1H, t, J=8.0 Hz), 6.71 (1H, d, J=6.8 Hz), 5.11 (2H, s), 4.84 (1H, br. s.), 3.75 (1H, br. s.), 3.54 (1H, br. s.), 3.14 (3H, br. s.), 2.96 (3H, s), 2.75 (1H, br. s.), 2.33-2.41 (1H, m), 2.30 (3H, br. s.). Mass spectrum m/z 465, 467 (M)+.

1. concentrationthe mixture (a solution with an insoluble reddish oil) was concentrated under vacuum
2. additionThe residue was treated three times with DCM
3. concentrationconcentrated under vacuum