Dimethylformamide → 1,8-Naphthyridine-1(2H)-carboxamide, 7-(dimethoxymethyl)-3,4-dihydro-6-(hydroxymethyl)-N-[5-(trifluoromethyl)-2-pyridinyl]-

Participants

Reaction Steps

A solution of 6-bromo-7-(dimethoxymethyl)-N-(5-(trifluoromethyl)pyridin-2-yl)-3,4-dihydro-1,8-naphthyridine-1(2H)-carboxamide (intermediate 2D, 100 mg, 0.210 mmol) in THF (2 ml) at −78° C. under argon was treated drop wise with n-BuLi (1.5 M in hexane, 0.309 ml, 0.463 mmol). The resulting brown solution was stirred for 2 min and then DMF (0.1 ml, 1.29 mmol) was added. The resulting yellow solution was stirred at −78° C. for 15 min. The reaction mixture was quenched by addition of sat. aq. NH4Cl, warmed to room temperature and extracted with EtOAc (2×). The combined organic layers were washed with brine, dried over Na2SO4, filtered and concentrated under reduced pressure. The residue was purified by normal phase chromatography (12 g silica gel cartridge, heptanes/EtOAc 100:0 to 0:100) the 7-(dimethoxymethyl)-6-formyl-N-(5-(trifluoromethyl)pyridin-2-yl)-3,4-dihydro-1,8-naphthyridine-1(2H)-carboxamide containing fractions were concentrated to give a white solid. This material was dissolved in MeOH (2 ml) and DCM (1 ml), treated at room temperature with NaBH4 (6.36 mg, 0.168 mmol) and stirred for 0.5 h. The reaction mixture was quenched with sat. aq. NH4Cl and extracted with DCM (3×). The combined organic layers were dried over Na2SO4, filtered and concentrated under reduced pressure. The crude material was purified by normal phase chromatography (12 g silica gel cartridge, heptanes/EtOAc 100:0 to 0:100) the product containing fractions were concentrated to give the title compound as a white solid. (UPLC-MS 1) tR 1.10 min; ESI-MS 421.0 [M+H]+.

Provenance & Evidence