反应详情

A mixture of tert-butyl (2-mercapto-benzoimidazol-1-yl)-acetate (Intermediate 3-1,264 mg, 1 mmol), 3-bromomethyl-benzoic acid methyl ester (252 mg, 1.1 mmol) and K2CO3 (276 mg, 2 mmol) in acetone (4 ml) is allowed to stir at rt for 2.5 h. The suspension is cooled down to rt and filtered on a funnel filled with cotton wool. Evaporation of the solvent in vacuo affords a residue that is purified by flash-chromatography on silica-gel (AcOEt/heptane, 1:3), yielding the title compound (310 mg) in 75% as a colourless syrup: tR=7.19 min (LC-1), ESI-MS (pos.): m/z 413.3 [M+H]+; 1H-NMR (CDCl3): δ (ppm) 1.42 (s, 9H, tBu), 3.92 (s, 3H, OMe), 4.65 (s, 2H), 4.69 (s, 1H), 7.19-7.26 (m, 3Harom), 7.36 (t, 1Harom), 7.59 (d, 1Harom), 7.73 (m, 1 Harom), 7.92 (d, 1Harom), 8.06 (s, 1Harom).

1. temperatureThe suspension is cooled down to rt
2. filtrationfiltered on a funnel
3. additionfilled with cotton wool
4. customEvaporation of the solvent in vacuo
5. customaffords a residue that
6. customis purified by flash-chromatography on silica-gel (AcOEt/heptane, 1:3)