LGD-3303 synthesis

Yield:917891-35-1 62%

Reaction Conditions:

with 2,3-dicyano-5,6-dichloro-p-benzoquinone in ethyl acetate at 20; for 0.5 h;

Steps:

80

Example 80 9-Chloro-2-ethyl-1-methyl-3-(2,2,2-trifluoro-ethyl)-3,6-dihydro-pyrrolo[3,2-f]quinolin-7-one; Compound 183, Structure 6 of Scheme I, where R^A=chloro, R¹=methyl, R³=ethyl, R⁵=2,2,2-trifluoroethylTo a solution of Compound 128 (Example 25) (0.34 g, 1.0 mmol) in 30 mL EtOAc was added DDQ (0.35 g, 1.5 mmol, 1.5 eq) in small portions. The resulting green mixture was stirred at rt for about 30 min until almost no more starting material was visible on TLC. Then 5% aq. NaHCO₃ (30 mL) was added and the mixture was extracted with EtOAc (3×50 mL) and the combined organic layers were washed with 5% aq. NaHCO₃ (30 mL) and brine, dried over MgSO₄ and concentrated. Purification by chromatography (Silica gel, hexane:EtOAc 2:1 to 0:1 gradient) afforded Compound 182 (0.21 g, 62%) as a slightly yellow solid. Spectral data for compound 183: ¹H NMR (500 MHz, DMSO-d₆) δ 11.96 (s, 1H.) 7.90 (d, J=8.9 Hz, 1H) 7.17 (d, J=8.9 Hz, 1H) 6.68 (s, 1H), 5.27 (q, J=9.1 Hz, 2H), 2.85 (q, J=7.5 Hz, 2H), 2.47 (s, 3H), 1.15 (t, J=7.5 Hz, 3H).

References:

US2009/30027,2009,A1 Location in patent:Page/Page column 52