Methyl iodide → 2-anilino-6,7-dimethyl-1-phenyl-1,8-naphthyridin-4(1H)-one

Participants

Reaction Conditions

Reaction Steps

A suspension of 2-anilino-6-bromo-7-methyl-1-phenyl-1,8-naphthyridin-4(1H)-one (203 mg, 0.5 mmol) in THF (10 mL) in an atmosphere of argon was cooled to −78° C. A solution of n-BuLi in hexanes (1.0 mL, 1.6 mmol, 1.6 M) was added and the suspension was stirred for 10 min at 0° C. until it became a clear solution. Excessive MeI (0.2 mL, 3.2 mmol) was added, and the reaction was stirred for another 10 min. The reaction was quenched with saturated aqueous NH4Cl (2.0 mL) and water (10 mL) and the mixture was extracted with EtOAc. The organic layer was dried over MgSO4 and concentrated in vacuo. The residue was purified by prep-HPLC to afford 2-anilino-6,7-dimethyl-1-phenyl-1,8-naphthyridin-4(1H)-one (55 mg, 32%): LCMS RT: 2.33 min, MH+: 342.4, Rf=0.39 (EtOAc). 2-anilino-7-ethyl-1-(3-methylphenyl)-1,8-naphthyridin-4(1H)-one (13.3 mg, 7.5%) was also obtained as a side product: LCMS RT: 2.54 min, MH+: 356.3, Rf=0.40 (EtOAc). Other electrophiles such as aldehydes, carbon dioxide, disulfides, trifluoroacetates acid chlorides and other alkyl halides can also be used to quench the generated aryl lithium.

Provenance & Evidence