Water → 1-ethyl-7-methyl-3-{4-[(3-methyl-3H-imidazo[4,5-b]pyridin-2-yl)oxy]phenyl}-1,3-dihydro-2H-imidazo[4,5-b]pyridin-2-one

Participants

Reaction Conditions

Reaction Steps

A solution of 3-methyl-2-(methylsulfonyl)-3H-imidazo[4,5-b]pyridine (20.4 g, 96.55 mmol) in DMA (117 mL) was added to a solution of 1-ethyl-3-(4-hydroxyphenyl)-7-methyl-1,3-dihydro-2H-imidazo[4,5-b]pyridin-2-one (26.0 g, 96.55 mmol) and potassium tert-butoxide (11.4 g) in DMA (96 mL) at room temperature. The mixture was stirred at 95-100° C. for 1.5 h. Water (221 mL) was added at 80-100° C. The precipitate was collected at room temperature and dried over under reduced pressure to give 1-ethyl-7-methyl-3-{4-[(3-methyl-3H-imidazo[4,5-b]pyridin-2-yl)oxy]phenyl}-1,3-dihydro-2H-imidazo[4,5-b]pyridin-2-one (35.8 g) as crude product. The obtained crude 1-ethyl-7-methyl-3-{4-[(3-methyl-3H-imidazo[4,5-b]pyridin-2-yl)oxy]phenyl}-1,3-dihydro-2H-imidazo[4,5-b]pyridin-2-one (10.0 g) was dissolved in DMSO (150 mL) at 90-100° C. The solution was filtered through filter paper and washed with DMSO (10 mL). The combined filtrate was slowly added to a mixture of crystals (Form G: 100 mg) obtained in 120p) (as seed crystals) in AcOEt (100 mL) at 5-30° C. After stirring at room temperature for 17 h, the mixture was stirred at 70° C. for 1 h. The mixture was gradually cooled to 25° C. and stirred for 2 h. The mixture was stirred at 0-10° C. for 1 h and at room temperature for 1 h. The solids were collected by filtration and dried at 50° C. under reduced pressure to give 1-ethyl-7-methyl-3-{4-[(3-methyl-3H-imidazo[4,5-b]pyridin-2-yl)oxy]phenyl}-1,3-dihydro-2H-imidazo[4,5-b]pyridin-2-one (8.0 g) as white crystals (Form G).

Provenance & Evidence