Carbon Dioxide → 2,2'-Anhydro-1-beta-arabinofuranosylthymine

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A mixture of 5-methyluridine (16.77 g, 69.2 mmol), diphenyl carbonate (17.8 g, 83.1 mmol) and NaHCO3 (100 mg) in hexamethylphosphoramide (175 mL) was heated to 150° C. with stirring until evolution of CO2 ceased (approximately 1 hour). The reaction mixture was cooled and then poured into diethyl ether (1 L) while stirring to furnish a brown gum. Repeated washings with diethyl ether (4×250 mL) furnished a straw-colored hygroscopic powder. The solid was purified by short column chromatography on silica gel (400 g). Pooling and concentrating appropriate fraction, which were eluted with CH2Cl2—MeOH (85:15), furnished the title compound as a straw-colored solid (12 g, 77.3%), which crystallized from EtOH as long needles, m.p. 226–227° C.

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