tert-Butyl acrylate → (E)-tert-butyl 3-(6,6-dimethyl-7-oxo-5,6,7,8-tetrahydro-1,8-naphthyridin-3-yl)acrylate

Participants

Reaction Conditions

Reaction Steps

A suspension of 6-bromo-3,3-dimethyl-3,4-dihydro-1,8-naphthyridin-2(1H)-one (434 mg, 1.7 mmol), tert-butyl acrylate (1.23 mL, 8.5 mmol) and (i-Pr)2EtN (0.9 mL, 5.1 mmol) in DMF (25 mL) was de-oxygenated with Ar for 30 min. The mixture was treated with Pd(OAc)2 (38 mg, 0.17 mmol) and P(o-tol)3 (103 mg, 0.34 mmol) then heated to 110° C. for 22 h. The hot mixture was filtered through a pad of celite and washed with ethyl acetate (50 mL). The filtrate was diluted with H2O (100 mL) and extracted with ethyl acetate (2×50 mL). The combined organic layers were washed with water, then brine, dried over magnesium sulphate, and concentrated in vacuo. The resulting brown solid was then triturated with a diethyl ether followed by filtration to yield the white solid product. Yield 178 mg (35%); 1H NMR (300 MHz, DMSO-d6) δ 10.68 (s, 1H), 8.39 (s, 1H), 8.04 (s, 1H), 7.52 (d, J=16.1 Hz, 1H), 6.52 (d, J=15.8 Hz, 1H), 2.80 (s, 2H), 1.49 (s, 9H), 1.09 (s, 6H); ESI MS m/z 303 [C17H22N2O3+H]+

Provenance & Evidence