反应详情

(R)-tert-Butyl 3-(1H-benzo[d]imidazol-2-yl)piperidine-1-carboxylate (7B) (9.95 mmol, 3.0 g) was added to a 200 mL round-bottomed flask equipped for stirring under nitrogen. DMF (50 mL) was added and the resultant solution was cooled to 0° C. with an ice bath. NaH (60% in mineral oil, 11.95 mmol, 0.478 g) was then added and the subsequent solution was allowed to stir under nitrogen for 0.5 hr. At this time 1-bromo-3-methoxypropane (12.44 mmol, 1.90 g) was added, the ice bath was removed and the reaction solution was allowed to warm to room temperature and stir fort hr. The reaction solution was then poured into ice-water, extracted with ethyl acetate, and washed once with saturated aqueous sodium chloride. The organic layer was collected and subsequently dried with anhydrous Na2SO4 and filtered. This filtrate was collected, concentrated, and dried in-vacuo affording a brown oil. This material was then purified by chromatography on silica gel (3-10% CH3OH in CH2Cl2) to afford (R)-tert-butyl 3-(1-(3-methoxypropyl)-1H-benzo[d]imidazol-2-yl)piperidine-1-carboxylate (7C) as a brown oil (9.63 mmol, 3.6 g, 96% yield). 1H NMR (400 MHz, DMSO-d6) δ ppm 1.55-1.71 (br.s., 1H) 1.79-1.88 (br.s., 1H) 2.04-2.13 (m, 4H) 2.74-2.88 (br.s., 1H) 2.98-3.38 (m, 7H) 4.21-4.39 (m, 3H) 7.22-7.28 (m, 2H) 7.34-7.40 (dd, 1H, 6.57 Hz, 2.02 Hz) 7.72-7.77 (dd, 1H, 6.57 Hz, 2.02 Hz). ESI-MS: m/z 374.4 (M+H)+.

1. customequipped
2. stirringto stir under nitrogen for 0.5 hr
3. customthe ice bath was removed
4. stirringstir fort hr
5. additionThe reaction solution was then poured into ice-water
6. extractionextracted with ethyl acetate
7. washwashed once with saturated aqueous sodium chloride
8. customThe organic layer was collected
9. dry with materialsubsequently dried with anhydrous Na2SO4
10. filtrationfiltered
11. customThis filtrate was collected
12. concentrationconcentrated
13. customdried in-vacuo
14. customaffording a brown oil
15. customThis material was then purified by chromatography on silica gel (3-10% CH3OH in CH2Cl2)