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

Participants

Reaction Conditions

Reaction Steps

To the stirred solution of 8-chloro-2,6-dimethylbenzo[c][2,7]naphthyridin-5(6H)-one (100 mg, 0.387 mmol) and tert-butyl (1-hydroxy-2,4-dimethylpentan-2-yl)carbamate (168 mg, 0.773 mmol) in toluene (5 mL) was added cesium carbonate (189 mg, 0.580 mmol) and 2-di-t-butylphosphino-2′,4′,6′-tri-i-propyl-1,1′-biphenyl (9.85 mg, 0.023 mmol). The reaction mixture was degassed with argon for 5 minutes and palladium(II) acetate (26 mg, 0.116 mmol) was added. The reaction mixture was heated to 100° C. for 18 h. The reaction mixture was filtered through diatomaceous earth (Celite®) and the filtrate was concentrated under reduced pressure. The residue was purified by silica gel chromatography using ethyl acetate-petroleum ether to afford (S)-tert-butyl (1-((2,6-dimethyl-5-oxo-5,6 dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (100 mg, 0.171 mmol, 44% yield) as a dark yellow semi-solid. LC/MS (ESI) m/e 440.6 [(M+H+)+, calcd for C25H34N3O4 440.2]; LC/MS retention time (method D): tR=0.89 min.

Provenance & Evidence