反应详情

2-Butyl-1-[(2'-(2-triphenylmethyl-2H-tetrazol-5-yl)biphenyl-4-yl)methyl]benzimidazole (E) (400 mg) was dissolved in an 8M solution of hydrogen chloride in dioxan (5 ml) and water (0.5 ml) was added. The solution was allowed to stand for 1.5 hours and then volatile material was removed by evaporation. The residue was partitioned between sodium hydrogen carbonate solution (10 ml) and ether (10 ml). The aqueous phase was separated, washed with ether (3×10 ml) and acidified to pH4 with 20% aqueous citric acid. The precipitated solid was collected and recrystallised from ethyl acetate to give 2-butyl-1-[(2'-(1H-tetrazol-5-yl)biphenyl-4-yl)methyl]benzimidazole (94 mg), as white crystals, m.p. 230°-232° C.; NMR (d6 -DMSO): 0.88(t,3H), 1.35(m,2H), 1.7(m,2H), 2.8(t,2H), 5.5(s,2H), 7.0(s,4H), 7.15(m,2H), 7.4-7.7 (complex, 6H); mass spectrum (-ve FAB, DMSO/NBA): 407 (M-H)-, 379; microanalysis found: C,73.7; H,6.2; N,20.8; C25H24N6 requires: C,73.5; H,5.9; N,20.6%.

1. additionwas added
2. customvolatile material was removed by evaporation
3. customThe residue was partitioned between sodium hydrogen carbonate solution (10 ml) and ether (10 ml)
4. customThe aqueous phase was separated
5. washwashed with ether (3×10 ml)
6. customThe precipitated solid was collected
7. customrecrystallised from ethyl acetate