Reaction Steps
A suspension of 2-(3-bromo-2-methylphenyl)-1H-pyrrolo[3,4-c]pyridine-1,3(2H)-dione (4.7 g, 14.82 mmol) in methanol (200 mL) was treated with sodium borohydride (2 g, 52.9 mmol) and stirred at rt for 1 h. The mixture was concentrated and the residue was treated with NaHCO3 (aq). The mixture was extracted several times with a mixture of DCM and methanol. The combined organic phases were washed with water, dried and concentrated to give a mixture of N-(3-bromo-2-methylphenyl)-4-(hydroxymethyl)-nicotinamide and N-(3-bromo-2-methylphenyl)-3-(hydroxymethyl)isonicotinamide as an off-white solid. Mass spectrum m/z 321, 323 (M+H)+. Without purification, this material was suspended in THF (250 mL) and treated with triphenylphosphine (polymer supported, 3 mmol P/g resin, 18.44 g, 54.8 mmol) and diethyl azodicarboxylate (6.45 g, 37.1 mmol) and the mixture was stirred at rt for 4 h. The mixture was filtered and concentrated, and the residue was dissolved in DCM, washed with water, NaHCO3 (aq) and brine, and dried and concentrated. The residue was subjected to column chromatography (eluting with EtOAc) to provide 2-(3-bromo-2-methylphenyl)-2,3-dihydro-1H-pyrrolo[3,4-c]pyridin-1-one as a white solid (Intermediate 44-1, 2.7 g, 60%). 1H NMR (400 MHz, chloroform-d) δ 9.21 (1H, d, J=0.88 Hz), 8.84 (1H, d, J=5.06 Hz), 7.63 (1H, dd, J=7.70, 1.32 Hz), 7.51 (1H, dd, J=5.06, 0.88 Hz), 7.22 (1H, dt, J=7.70, 1.32 Hz), 7.17 (1H, d, J=7.92 Hz), 4.76 (2H, s), 2.31 (3H, s). Mass spectrum m/z 303, 305 (M+H)+. Also obtained was (Z)-3-bromo-N-(furo[3,4-c]pyridin-1(3H)-ylidene)-2-methylaniline as a white solid (Intermediate 44-2, 760 mg, 17%), which also contained the isomeric (Z)-3-bromo-N-(furo[3,4-c]pyridin-3(1H)-ylidene)-2-methylaniline. 1H NMR (400 MHz, chloroform-d) δ 9.26 (1H, s), 8.80 (1H, d, J=5.06 Hz), 7.42 (1H, dd, J=5.06, 0.88 Hz), 7.31-7.35 (1H, m), 7.02-7.08 (2H, m), 5.39 (2H, s), 2.35 (3H, s). Mass spectrum m/z 303, 305 (M+H)+.
