Dimethylformamide → HCID 59375987, Verbindung

Phosphorus oxychloride (674 μL, 4.04 mmol) and N,N-dimethylformamide (963 μL, 12.32 mmol) were dissolved in 21.18 mL of dichloromethane under stirring at room temperature, and the reaction solution was stirred for 15 minutes while maintaining the temperature at −10° C. in an ice-water bath. (R)-5-(2-hydroxy-3-morpholin-4-yl-propyl)-3-methyl-1,5,6,7-tetrahydro-pyrrolo[3,2-c]pyridin-4-one 1e (790 mg, 2.7 mmol) was dissolved in 10 mL of dichloromethane under stirring, and the solution was then added dropwise to the above reaction system. Upon completion of the addition, the ice-water bath was removed, and the reaction system was allowed to warm up to room temperature and stirred for another 2 hours. The reaction was completed until TLC showed the disappearance of starting materials, and the reaction system was quenched with iced water and stirred for 15 minutes. The mixture was adjusted to pH about 12 with 10N sodium hydroxide solution and extracted with the solvent mixture of dichloromethane and methanol (V:V=20:1, 100 mL ×8). The combined organic extracts were washed with saturated brine (150 mL), dried over anhydrous magnesium sulfate, filtered to remove the drying agent and concentrated under reduced pressure to give the crude product (800 mg). The crude product was purified by silica gel column chromatography to give the title compound (R)-5-(2-hydroxy-3-morpholin-4-yl-propyl)-3-methyl-4-oxo-4,5,6,7tetrahydro-1H-pyrrolo[3,2-c]pyridine-2-carbaldehyde 1f (650 mg, yield 75%) as a white solid.