Stannous Chloride → Ethyl 4-(5-amino-3-methyl-4-oxo-1,4-dihydroquinolin-8-yl)cyclohex-3-ene-1-carboxylate

Participants

Reaction Steps

A solution of ethyl 4-(3-methyl-5-nitro-4-oxo-1,4-dihydroquinolin-8-yl)cyclohex-3-ene-1-carboxylate (Compound 304D, 600 mg, 1.69 mmol) in EtOH (50 mL) was charged with SnCl2 (1.2 g, 5.33 mmol). The resulting mixture was stirred under reflux for 18 h. The reaction mixture was concentrated under reduced pressure. The residue was quenched with aq. NaHCO3 solution (500 mL) and extracted with EtOAc (3×200 mL). The combined organic layers were dried over Na2SO4, filtered and concentrated under reduced pressure. The material was purified by prep TLC to afford the desired compound (270 mg, yield: 49%). 1H NMR (CDCl3, 400 MHz): δ=1.22 (t, J=7.2 Hz, 3 H), 1.99 (s, 3 H), 2.03 (m, 1 H), 2.11-2.13 (m, 2 H), 2.19-2.21 (m, 2 H), 2.34-2.39 (m, 2 H), 2.78 (m, 1 H), 3.42 (d, J=3.2 Hz, 1 H), 4.12 (q, J=7.2 Hz, 2 H), 5.71 (s, 1 H), 6.20 (d, J=8.0 Hz, 1 H), 6.71 (s, br, 2 H), 6.93 (d, J=8.0 Hz, 1 H), 7.36 (d, J=6.0 Hz, 1 H), 8.91 (s, br, 1 H).

Provenance & Evidence