4-Chloro-7-methyl-7H-pyrrolo[2,3-d]pyrimidine

3680-69-1

74-88-4

7781-10-4

The general procedure for the synthesis of 4-chloro-7-methylpyrrolo[2,3-D]pyrimidine from 4-chloropyrrolopyrimidine and iodomethane was as follows: iodomethane (12.2 mL, 195 mmol) was added slowly and dropwise to a solution containing 4-chloro-7H-pyrrolo[2,3-d]pyrimidine (15.0 g, 97.7 mmol) and cesium carbonate (47.7 g, 146.5 mmol) in a N,N-dimethylformamide (DMF, 200 mL) solution. The reaction mixture was stirred at room temperature for 1 h. The reaction was subsequently quenched with deionized water (500 mL). The reaction mixture was extracted with ethyl acetate (3 x 200 mL), the organic phases were combined and dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated under reduced pressure. Purification of the crude product by fast column chromatography (silica gel, gradient elution with ethyl acetate:hexane, 2:8 to 3:7) afforded 4-chloro-7-methylpyrrolo[2,3-D]pyrimidine as an off-white solid (15.4 g, 94% yield). Mass Spectrometry (MS): m/z 168.5 ([M+H]+); High Performance Liquid Chromatography (HPLC) retention time (Rf): 3.45 min (HPLC method 4); HPLC purity: 96%.