Sodium hydride → 3-(4-Dimethylamino-2-oxobutyl)-2-(7-methoxy-1,8-naphthyridin-2-yl)-1-isoindolinone

Participants

Reaction Conditions

Reaction Steps

Sodium hydride (0.7 g) is added in small portions at a temperature in the region of -5° C. to a solution, maintained under an argon atmosphere, of 3-hydroxy-2-(7-methoxy-1,8-naphthyridin-2-yl)-1-isoindolinone (8.0 g) in anhydrous dimethylformamide (125 cc). The suspension obtained is stirred for 30 minutes at a temperature in the region of -5° C. and then treated with a solution of 4-dimethylamino-2-butanone (3.5 g) in anhydrous dimethylformamide (5 cc). The mixture is stirred for 3 hours at a temperature in the region of 20° C., and is then poured into distilled water (500 cc) and extracted with dichloromethane (3×200 cc). The organic phases are combined, washed with distilled water (4×25 cc), dried over magnesium sulphate, filtered and then concentrated to dryness under reduced pressure (2.7 kPa) at 40° C. The oily residue obtained is dissolved in ethyl acetate (400 cc) and the solution obtained is extracted with 1 N aqueous hydrochloric acid solution (2×100 cc). The aqueous phases are combined, washed with ethyl acetate (50 cc), alkalinized with 10 N aqueous sodium hydroxide solution to a pH in the region of 11 and extracted with ethyl acetate (2×250 cc). The organic phases are combined, washed with distilled water (3×30 cc), dried over magnesium sulphate, filtered and then concentrated to dryness under reduced pressure (2.7 kPa) at 60° C. After recrystallization in acetonitrile, 3-(4-dimethylamino-2-oxobutyl)-2-(7-methoxy-1,8-naphthyridin-2-yl)-1-isoindolinone (2.6 g), m.p. 140° C., is obtained.

Provenance & Evidence