反应详情

Glacial acetic acid (1.3 mL, 22.7 mmol) and sodium triacetoxyborohydride (6.73 g, 31.7 mmol) were added to a solution of 5-aminoindole (3 g, 22.7 mmol), 4-oxo-piperidine-1-carboxylic acid tert-butyl ester (4.52 g, 22.7 mmol) in 1,2-dichloroethane (100 mL). The reaction mixture was stirred for 4 hours at room temperature; an aqueous solution of NaOH (1 M, 100 mL) was then added. The organic layer was separated, dried over MgSO4, filtered and evaporated under reduced pressure to give 6.9 g (96% yield) of 4-(1H-indol-5-ylamino)-piperidine-1-carboxylic acid tert-butyl ester as a black foam; this material was used without further purifications for the next step.

1. customThe organic layer was separated
2. dry with materialdried over MgSO4
3. filtrationfiltered
4. customevaporated under reduced pressure