Cesium carbonate → (S)-tert-butyl (1-((4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate

Participants

Reaction Conditions

Reaction Steps

A mixture of 8-chloro-4,6-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one (60 mg, 0.232 mmol), (S)-tert-butyl (1-hydroxy-4-methylpentan-2-yl)carbamate (101 mg, 0.464 mmol), Cs2CO3 (113 mg, 0.348 mmol), Pd(OAc)2 (15.6 mg, 0.070 mmol) and 2-di-t-butylphosphino-2′,4′,6′-tri-i-propyl-1,1′-biphenyl (5.91 mg, 0.014 mmol) in toluene (5 mL) was purged with nitrogen for 5 min and heated at 100° C. overnight (14 h). After cooling, the reaction mixture was filtered through diatomaceous earth (Celite®), concentrated under reduced pressure and dissolved in ethyl acetate (5 mL). The organic layer was washed with brine (2×10 mL) and water (20 mL); dried over Na2SO4 and concentrated under reduced pressure to afford (S)-tert-butyl (1-((4,6-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (55 mg crude) as a gummy solid. The crude product was used in the next step without further purification. LC/MS, (ESI) m/z 440.4 [(M+H)+, calcd for C25H34N3O4, 440.2]; LC/MS retention time (method D): tR=0.89 min.

Provenance & Evidence