Cesium carbonate → (S)-tert-butyl (4-methyl-1-((2-methyl-5H-chromeno[3,4-c]pyridin-8-yl)oxy)pentan-2-yl)carbamate

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Reaction Conditions

Reaction Steps

A mixture of 8-chloro-2-methyl-5H-chromeno[3,4-c]pyridine (0.2 g, 0.863 mmol), (S)-tert-butyl (1-hydroxy-4-methylpentan-2-yl)carbamate (0.225 g, 1.036 mmol), palladium(II) acetate (5.81 mg, 0.026 mmol), Cs2CO3 (0.422 g, 1.295 mmol) and 2-di-tert-butylphosphino-2′,4′,6′-triisopropylbiphenyl (0.022 g, 0.052 mmol) in toluene (5 mL) was heated to 110° C. for 18 h. After cooling, the mixture was filtered through celite and concentrated under reduced pressure. The crude product was purified by silica gel chromatography (70% EtOAc in pet. ether) to afford (S)-tert-butyl (4-methyl-1-((2-methyl-5H-chromeno[3,4-c]pyridin-8-yl)oxy)pentan-2-yl)carbamate, as a semi-solid (0.12 g, 0.291 mmol, 34% yield). LCMS (ESI) m/e 413.4 [(M+H)+, calcd for C24H33N2O4 413.2]; LC/MS retention time (Method D): tR=2.42 min.

Provenance & Evidence