[Br:1][C:2]1[C:10]2[N:9]=[N:8][N:7]([CH2:11][CH:12]3[CH2:14][CH2:13]3)[C:6]=2[CH:5]=[CH:4][C:3]=1[O:15]C.B(Br)(Br)Br>ClCCl>[Br:1][C:2]1[C:10]2[N:9]=[N:8][N:7]([CH2:11][CH:12]3[CH2:14][CH2:13]3)[C:6]=2[CH:5]=[CH:4][C:3]=1[OH:15]4-Bromo-1-(cyclopropylmethyl)-5-methoxy-1H-benzotriazole (8.0 g, 28 mmol) was dissolved in dichloromethane (200 mL), cooled to 0° C. and treated with boron tribromide (57 mL, 1 M dichloromethane solution, 57 mmol, 2 equiv). The ice bath was removed and the mixture was warmed to ambient temperature and stirred for 4 hours. The mixture was treated slowly with water (exotherm), the pH of the solution was adjusted to pH>10 with 1 N aqueous sodium hydroxide and stirred for an additional 30 minutes. The pH of the mixture was then adjusted to pH 6-7 with ammonium chloride (aqueous saturated) and extracted exhaustively with dichloromethane containing 5% methanol. The combined organic extracts were dried with sodium sulfate, filtered and concentrated in vacuo, providing the titled compound.
Wird geladen…