Pyridine → 3-Amino-5-(3,5-dimethylisoxazol-4-yl)-3-phenylindolin-2-one

Participants

Reaction Steps

Under N2, to a solution of 5-(3,5-dimethylisoxazol-4-yl)-3-hydroxy-3-phenylindolin-2-one (21 g, 65.6 mmol, 1.0 eq) in THF (300 mL) was added dropwise pyridine (30 mL) and SOCl2 (15 mL) at −15° C.˜−20° C., the mixture was stirred for 20 min at −15° C.˜−20° C., quenched with brine (50 mL), washed with brine (300 mL×2), the organic phase was concentrated to give 17.5 g crude product. The crude product was dissolved in NH3/MeOH (7M, 200 mL), and stirred for 2 hours at room temperature. Then the solvent was removed in vacuo to give crude product, which was dissolved in EA (200 mL), washed with water (100 mL), then brine (100 mL), dried over Na2SO4, concentrated to give 15 g crude product, which was purified by sili-gel to give 8.5 g (yield 40%) product as white solid. 1H NMR (DMSO-d6) δH 10.53 (s, 1H), 7.39-7.41 (d, 2H, J=8.0 Hz), 7.29-7.33 (t, 2H, J=8.0 Hz), 7.21-7.26 (m, 2H), 7.14 (s, 1H), 6.98-7.00 (d, 1H, J=8.0 Hz), 2.75 (s, 2H), 2.33 (s, 3H), 2.16 (s, 3H)

Provenance & Evidence