1,1'-Carbonyldiimidazole → 1-methyl-1H,4H,5H,6H,7H-pyrazolo(4,3-d)pyrimidine-5,7-dione

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

This compound was prepared following the method described in WO2008/071650. To a stirred solution of 1-methyl-4-nitro-1H-pyrazole-5-carboxamide (1.27 g, 9.06 mmol) in acetonitrile (35.6 mL) refluxed at 100° C. was added N,N-carbonyldimidazole (1.91 g, 11.78 mmol, 1.3 eq.) proportion wise over 1 hour. The reaction mixture was stirred at 100° C. under N2 for 18 hours. The resultant precipitate was filtered, rinsed well with cold acetonitrile, and pumped dry on high-vac to yield 1.38 g (91.5%) of a white solid. 1H NMR (DMSO-d6, 500 MHz) δ ppm 11.04 (broad d, 2H), 7.34 (s, 1H), 4.04 (s, 3H).

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