1060816-67-2

Step-1: 2-Chloro-7H-pyrrolo[2,3-d]pyrimidine (1 g, 6.5 mmol) was dissolved in acetonitrile (25 mL) at 5°C and sodium hydride (313 mg, 7.8 mmol) was added under stirring. The reaction mixture was warmed to room temperature and stirring was continued for 30 minutes. Subsequently, iodomethane was slowly added at 0 °C and then the reaction mixture was stirred at room temperature overnight. Upon completion of the reaction, the mixture was filtered through a diatomaceous earth pad and washed with acetonitrile (10 mL). The filtrate was concentrated and a portion of the product was obtained by recrystallization from ether. The mother liquor was further concentrated and purified by ISCO system (silica gel column, eluent: dichloromethane/ethyl acetate, 0 to 30% gradient). Combining the recrystallized and column chromatography-purified products, 2-chloro-7-methyl-7H-pyrrolo[2,3-d]pyrimidine (835 mg, 77% yield) was finally obtained.

[1] Patent: WO2016/171755, 2016, A1. Location in patent: Paragraph 0182
[2] Patent: US2010/298334, 2010, A1. Location in patent: Page/Page column 44
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