反应详情

To a suspension of 5-bromovaleryl chloride (24.8 mg, 16.6 μl, 0.12 mmol) and K2CO3 (31.2 mg, 0.23 mmol) in acetonitrile (3 ml) is added N-methylaniline (14.5 mg, 14.7 μl, 0.14 mmol). After 1 h of stirring, tert-butyl (2-mercapto-benzoimidazol-1-yl)-acetate (Intermediate 3-I, 30 mg, 0.11 mmol) is added and the resulting mixture is refluxed overnight. The crude suspension is filtered over a fritted funnel and the solvent evaporated in vacuo. The crude yellow oil is purified by flash-chromatography on silica gel (AcOEt/heptane, 2:1 containing 3% of Et3N), yielding the title compound (38.4 mg) in 75% as a yellowish oil: tR=6.84 min (LC-1), ESI-MS (pos.): m/z 455.46 [M+H]+, ESI-MS (neg.): m/z 452.19 [M−H]+; 1H-NMR (DMSO-d6): δ (ppm) 1.38 (s, 9H, tBu), 1.56 (m, 4H, CH2CH2), 2.03 (m, 2H, CH2C═O), 3.17 (m, 2H, SCH2), 3.31 (s, 3H, NMe), 4.92 (s, 2H, CH2CO2), 7.12-7.16 (m, 2Harom), 7.26-7.30 (m, 3Harom), 7.36-7.46 (m, 3Harom), 7.51 (m, 1Harom).

1. temperaturethe resulting mixture is refluxed overnight
2. filtrationThe crude suspension is filtered over a fritted funnel
3. customthe solvent evaporated in vacuo
4. customThe crude yellow oil is purified by flash-chromatography on silica gel (AcOEt/heptane, 2:1 containing 3% of Et3N)