反应详情

5-[[[[(phenylmethoxy)carbonyl]amino]carbonyl]amino]-1-(β-D-ribofuranosyl)-1H-imidazole-4-carboxylic acid diphenylmethyl ester (1.76 g, 2.9 mmol) was dissolved in the mixture of DMF (50 mL), THF (20 mL) and ethanol (30 mL) and mixed with 10% palladium on charcoal. The mixture was hydrogenated at 50 psig pressure for 2 h. The catalyst was removed by filtration through Celite, and washed extensively with DMF and ethanol. Combined washing and filtrate was concentrated under reduced pressure to dryness. Residue was dissolved in 30% aqueous ethanol and filtered through a C18-Sep-Pak to remove the last traces of catalyst. This eluate was concentrated to dryness and partitioned between water (100 mL) and ether (2×100 mL). The aqueous layer was concentrated to dryness, redissolved in water and evaporated again and pumped under high vacuum to give 5-[[(amino)carbonyl]amino]-1-(β-D-ribofuranosyl)-1H-imidazole-4-carboxylic acid as a colorless glass: yield 0.64 g (73%); IR (KBr) 3340, 1692 cm -1 ; NMR (Me2SO-d6) δ3.72-3.53 (m, 2), 3.84 (d, 1, J=4.3 Hz), 4.05 (s, 1), 4.14 (s, 1), 5.05 (s, 1), 5.11 (s, 1), 5.34 (s, 1), 5.50 (d, 1, J=4.3 Hz), 6.28 (s, 2), 7.92 (s, 1), 8.07 (s, 1); UV max (H2O) 215 nm (ε5800).

1. customThe catalyst was removed by filtration through Celite
2. washwashed extensively with DMF and ethanol
3. washCombined washing
4. concentrationfiltrate was concentrated under reduced pressure to dryness
5. dissolutionResidue was dissolved in 30% aqueous ethanol
6. filtrationfiltered through a C18-Sep-Pak
7. customto remove the last traces of catalyst
8. concentrationThis eluate was concentrated to dryness
9. custompartitioned between water (100 mL) and ether (2×100 mL)
10. concentrationThe aqueous layer was concentrated to dryness
11. dissolutionredissolved in water
12. customevaporated again