Hydrochloric Acid → 5,7-dichloro-3-(4-hydroxy-phenyl)-3-methyl-1H-quinoline-2,4-dione

Participants

Reaction Steps

To a pre-cooled (−78° C.) solution of 5,7-dichloro-3-(4-methoxy-phenyl)-3-methyl-1H-quinoline-2,4-dione (0.23 g, 0.77 mmol) in dichloromethane (5.0 mL) was added BBr3 (1.40 mL, 1.0 M dichloromethane solution) by syringe. The reaction was conducted for 20 hours at room temperature and qeunched by carefully addition of 1N HCl aqueous solution. Resultant was extracted with ethyl acetate (50 mL×2), washed with brine (50 mL) and water (50 mL×2), and dried over magnesium sulfate. After concentration of the organic phase, the residue was subjected to purify by a flash column chromatography (n-hexane:EtOAc=5:1) to give a pure objective compound (0.19 g, 83%) as yellow solid: 1H NMR (300 MHz, CD3OD) δ 1.58 (s, 3H, CH3), 6.65-6.71 (m, 2H, ArH), 6.91 (d, J=1.9 Hz, 1H, ArH), 6.94-6.99 (m, 2H, ArH), 7.03-7.06 (m, 1H, ArH); m.p. 222-223° C.; MS(EI) m/e 335 [M+], 188, 140, 120; HRMS m/e cacld. for C16H11NO3Cl2 335.0116, found 335.0112.

Provenance & Evidence