Diphenyl carbonate → phenyl 7-(dimethoxymethyl)-3,4-dihydro-1,8-naphthyridine-1(2H)-carboxylate

Participants

Reaction Steps

A solution of 7-(dimethoxymethyl)-1,2,3,4-tetrahydro-1,8-naphthyridine (intermediate 4, 2 g, 9.60 mmol) and diphenylcarbonate (4.11 g, 19.21 mmol) in THF (40 ml) at −15° C. was treated with LHMDS (1M in THF, 13.3 ml, 13.3 mmol) over 0.5 h. The reaction mixture was quenched with sat. aq. NH4Cl, extracted with EtOAc (2×). The combined organic layers were washed with brine, dried over Na2SO4, filtered and concentrated under reduced pressure. The crude product was purified by normal phase chromatography (80 g silica gel cartridge, heptanes/EtOAc 100:0 to 25:75) to give the title compound as a pale yellow solid. 1H-NMR (400 MHz, DMSO-d6) δ 7.65 (d, 1H), 7.46-7.38 (m, 2H), 7.27-7.18 (m, 4H), 5.17 (s, 1H), 3.87-3.80 (m, 2H), 3.26 (s, 6H), 2.83 (t, 2H), 2.00-1.92 (m, 2H).

Provenance & Evidence