Acetone → 2-Imino-9-pentofuranosyl-3,9-dihydro-2H-purine-6-sulfinamide

Participants

Reaction Steps

A mixture of 2-amino-9-β-D-ribofuranosyl-9H-purine-6-sulfenamide (18) (1.57 g, 0.005 mol), ethanol (700 mL) and water (50 mL) was vigorously stirred and cooled in an ice bath. After the temperature of the suspension had decreased to <10° C., acetone was added to the ice bath to obtain a temperature of <0° C. With continual stirring a solution of commercially available (Aldrich Chem Co.) 3-chloroperoxybenzoic acid (80-85%, 1.0 g, 0.0046-0.0049 mol) in ethanol (40 mL) was added dropwise over a period of approx. 15 min. The reaction flask was stoppered, the mixture was allowed to stir and warm as the ice melted, and then stirred at ambient temperature for a total reaction time of 19 hr. The reaction mixture was filtered (Whatman GF/A glass microfiber filter) to remove a trace of undissolved solid and then the filtrate was evaporated in vacuo and at a temperature of >25° C. to near dryness. The product was washed from the evaporation flask with acetone (50-100 mL) and the solid was collected by filtration, suspended in diethyl ether (50 mL), refiltered, dried under vacuum at ambient temperature: (1.3 g, 0.0042 mol, 85%), m.p. 183°-185° C. dec. with prior sintering and darkening. IR (KBr): 1040 (vs, S=O), 3000-3600 (NH2, OH)cm-1 : UV: λmax (pH 1) 333 nm (ε2,900): λmax (pH 7) 326 nm (ε10,700): λmax (pH 11) 325 nm (ε8,700): 1H NMR (DMSO-d6): δ 5.85 (d, 1, J =5.52 Hz, C1'H), 6.49 (s, 2, SONH2, exchanged with D2O), 6.98 (s, 2, NH2, exchanged with D2O), 8.45 (s, 1, C8 e,uns/H/ ), and other sugar protons. Anal. Calcd. for C10H14N6O5S.1/2C2H5OH (353.32): C, 37.39: H, 4.82: N, 23.80: S, 9.07. Found: C, 37.29: H, 4.56: N, 23.78: S, 8.92.

Provenance & Evidence