反应详情

164 mg of 3-(5-Formylpyridin-2-yl)-2-hydroxy-1H-indole-5-carbonitrile (0.62 mmol) from example 1.3 were dissolved in DMSO at 50° C. To this solution 134 mg (1.18 mmol) of hexahydro-1H-furo[3,4-c]pyrrole were added and the resulting deep-red solution was stirred at this temperature for 90 min. Afterwards 263 mg (1.24 mmol) of sodium triacetoxyborohydride were added and the mixture was stirred for 4 h and then cooled to RT followed by further stirring for 16 h. The reaction mixture was diluted with ethyl acetate (20 mL) and washed with sat. NaHCO3 solution. The aqueous phase was re-extracted with ethyl acetate and the combined organic phases were washed with brine (5×), dried over Na2SO4, filtered, and evaporated under reduced pressure. The crude was purified by flash chromatography (silica gel, DCM/MeOH) yielding a yellow solid. Amount 95 mg. Yield 42%.

1. stirringthe mixture was stirred for 4 h
2. stirringby further stirring for 16 h
3. washwashed with sat. NaHCO3 solution
4. extractionThe aqueous phase was re-extracted with ethyl acetate
5. washthe combined organic phases were washed with brine (5×)
6. dry with materialdried over Na2SO4
7. filtrationfiltered
8. customevaporated under reduced pressure
9. customThe crude was purified by flash chromatography (silica gel, DCM/MeOH)
10. customyielding a yellow solid