Tert-butyl 3-oxopiperidine-1-carboxylate → HCID 66786630, compound

Participants

Reaction Conditions

Reaction Steps

1-(3-methoxypropyl)-1H-benzo[d]imidazole (137A) (9.62 mmoles; 1.83 g) was added to an oven dried 250 mL round-bottomed flask equipped with an addition funnel and for stirring under nitrogen. Et2O (75 mL) was added and the solution was cooled to −78° C. with an acetone/CO2(s) bath. N-BuLi (2.5M in hexanes, 10.1 mmoles, 4.0 mL) was added drop-wise via syringe and the resultant solution was allowed to stir at −78° C. for 45 minutes. Tert-butyl 3-oxopiperidine-1-carboxylate (10.1 mmoles, 2.01 g) in END (25 mL) was then added drop-wise to the reaction solution at −78° C. via addition funnel and allowed to stir for 1 hr. The reaction solution was then allowed to warm to rt and stir for ihr. 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 Na.2SO4 and filtered. The filtrate was collected, concentrated, and dried in-vacuo. The residue was then partially purified by chromatography on silica gel (5-15% CH3OH/CH2Cl2) to afford tert-butyl 3-hydroxy-3-(1-(3-methoxypropyl)-1H-benzo[d]imidazol-2-yl)piperidine-1-carboxylate (137E) as a mixture of products that was carried onto the next step without further purification. ESI-MS: m/z 390.4 (M+H)+.

Provenance & Evidence