A mixture of 8-chloro-4-methyl-5H-chromeno[3,4-c]pyridine (60 mg, 0.259 mmol), (S)-(−)-2-(tert-butoxycarbonylamino)-4-methyl-1-pentanol (113 mg, 0.518 mmol), 2-di-t-butylphosphino-2′,4′,6′-tri-1-propyl-1,1′-biphenyl (6.60 mg, 0.016 mmol), Cs2CO3 (127 mg, 0.388 mmol) and Pd(OAc)2 (1.744 mg, 7.77 μmol) in toluene (5 mL) was heated at 80° C. for 16 h. After cooling to rt, the mixture was diluted with EtOAc (10 mL) and water (10 mL). The organic layer was dried over Na2SO4, filtered and concentrated under reduced pressure to afford (S)-tert-butyl (4-methyl-1-((4-methyl-5H-chromeno[3,4-c]pyridin-8-yl)oxy)pentan-2-yl)carbamate, (0.2 g, 0.485 mmol, 30% yield) as a yellow solid. LCMS (ESI) m/e 413.39 [(M+H)+, calcd for C24H33N2O4 413.24]; LC/MS retention time (Method F): tR=0.97 min.
