反应详情

A solution of 4-(1H-benzoimidazole-2-sulfonyl)-butylamine (350 mg, 1.4 mmol) and 3,5-dimethylpyridine-2-carbaldehyde (187 mg, 1.4 mmol) in dry MeOH (10 mL) was stirred for 3 h. At this time, solid NaBH4 (116 mg, 4.2 mmol) was added in one portion. Stirring was continued for 1 h, then saturated aqueous NaHCO3 (10 mL) and CH2Cl2 (20 mL) was added. The biphasic mixture was extracted with CH2Cl2 (3×20 mL), then the combined organic fractions were dried (MgSO4), and concentrated. Purification of the crude material by flash chromatography (silica gel, CH2Cl2/MeOH/NH4OH; 20:2:1) afforded 70 mg of [4-(1H-benzoimidazole-2-sulfonyl)-butyl]-(3,5-dimethyl-pyridin-2-ylmethyl)-amine (14% yield). 1H NMR (CDCl3) δ 184-1.86 (m, 4H), 2.26 (s, 3H), 2.29 (s, 3H), 2.95-3.00 (m, 2H), 3.34-3.56 (m, 2H), 4.12 (s, 2H), 7.34-7.37 (m, 2H), 7.44 (s, 1H), 7.67-7.71 (m, 2H), 8.19 (s, 1H).

1. extractionThe biphasic mixture was extracted with CH2Cl2 (3×20 mL)
2. dry with materialthe combined organic fractions were dried (MgSO4)
3. concentrationconcentrated
4. customPurification of the crude material by flash chromatography (silica gel, CH2Cl2/MeOH/NH4OH; 20:2:1)