反应详情

6-(Cyclopropylmethylamino)-9-[(2R,5S)-tetrahydro-5-(hydroxymethyl)-2-furyl]-9H-purine (0.624 g, 2.1 mmoles), 4-dimethylaminopyridine (27 mg, 0.2 mmoles, Aldrich Chemical Co., Madison, Wis.), and triethylamine (2.0 mL, 14 mmoles, Aldrich Chemical Co., Madison, Wis.) were dissolved in 100 mL acetonitrile. Valeryl chloride (1.08 mL, 8.9 mmoles, Aldrich Chemical Co., Madison, Wis.) was added and the reaction was stirred at room temperature for 6 hours. The reaction was quenched with methanol and solvents were evaporated in vacuo. The residue was dissolved in acetone and passed over a silica gel column (4.8×13 cm). After evaporation of the solvent, the product was further purified on a Chromatotron (4 mm silica gel plate) with a mixture of hexane:acetone (85:15). The product containing fractions were combined, concentrated, and loaded onto preparative silica gel plates (20×20×0.2 cm). The plates were developed in a mixture of chloroform-acetone (80:20). The product was scraped from the preparative plate and eluted from the silica gel with ethanol. The product was then flash chromatographed on a silica gel column (2.5×40 cm) with a mixture of chloroform:acetone (95:5). Lyophilization afforded 0.463 g of 6-(cyclopropylmethylamino)-9-((2R,5S)-5-((pentanoyloxy)methyl)-tetrahydro-2-furyl)-9H-purine as an oil (58% yield).

1. customThe reaction was quenched with methanol and solvents
2. customwere evaporated in vacuo
3. dissolutionThe residue was dissolved in acetone
4. customAfter evaporation of the solvent
5. customthe product was further purified on a Chromatotron (4 mm silica gel plate) with a mixture of hexane:acetone (85:15)
6. additionThe product containing fractions
7. concentrationconcentrated
8. additionThe plates were developed in a mixture of chloroform-acetone (80:20)
9. washeluted from the silica gel with ethanol
10. customflash chromatographed on a silica gel column (2.5×40 cm) with a mixture of chloroform:acetone (95:5)