Dimethylformamide → HCID 22082693, compound

Participants

Reaction Conditions

Reaction Steps

A mixture of naphthyridine 2-5 (15.8 g, 77.2 mmol), ester 2-6 (prepared from 4-pentynoic acid and methanolic HCl solution, 11.3 g, 100.4 mmol), CuI (0.7 g, 3.9 mmol), 100 mL Et3N and 100 mL DMF was gently degassed with argon for 10 min. Then Pd(PPh3)2Cl2 was added in one portion. The reaction mixture was heated at 53° C. for 20 hr, cooled to room temperature and quenched with 500 mL water and 100 mL NaHCO3 (sat.). The aqueous mixture was extracted three times with ethyl acetate. The combined organic layer was washed with brine and dried over MgSO4. After solvent removal, the residue was purified by silica gel flash chromatography (EtOAc/Hexane=¼ to 100% EtOAc over 30 min) to afford an oil, which was subsequently dissolved in 150 mL THF and 50 mL EtOH. Et3N (15 mL, 104 mmol) and PtO2 (0.7 g) were added. The mixture was degassed under moderate vacuum and subjected to balloon hydrogenation condition for 6 hrs. It was then filtered and concentrated to provide the desired product 2-7 as an oil.

Provenance & Evidence