[CH2:1]([N:8]([CH2:13][C:14]([C:16]1[CH:21]=[CH:20][CH:19]=[CH:18][C:17]=1[Br:22])=[O:15])[CH2:9][CH2:10][C:11]#[N:12])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[BH4-].[Na+]>CO>[CH2:1]([N:8]([CH2:13][CH:14]([C:16]1[CH:21]=[CH:20][CH:19]=[CH:18][C:17]=1[Br:22])[OH:15])[CH2:9][CH2:10][C:11]#[N:12])[C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1The 131.9 g of product obtained in Step 1 are dissolved in 300 ml of methanol and then added dropwise to 39.9 g of sodium borohydride in 300 ml of methanol. The temperature is maintained at 0° C. throughout the period of addition; the reaction mixture is then left at ambient temperature overnight and is subsequently evaporated to dryness, taken up in dichloromethane and washed with water. After concentrating under reduced pressure, chromatography on silica gel (dichloromethane) allows 94 g of expected product to be isolated.
Wird geladen…