反应详情

BCl3 gas (72.9) was bubbled in CH2Cl2 (610 ml) at 0°in a 2-l., 3-necked flask equipped with a thermometer, magnetic stirrer, and addition funnel and the stirred solution then cooled to -72° (dry ice-acetone) before the dropwise addition (1 hr) of a cold solution of 9-(2,3,5-tri-O-benzyl-β-D-arabinofuranosyl)-2-fluoroadenine (II, 7.0 g, 12.5 mmol) in CH2Cl2 (70 ml). After a total reaction time of 23/4 hr, the cooling bath was removed and the solvent and gas removed in vacuo. The residue was dissolved in CH2Cl2 (40 ml) and the solution evaporated to dryness (six times), or until a solid white residue is obtained, before adding 450 ml of 5% NaHCO3 followed by solid NaHCO3 to adjust the pH to 6-7. The mixture was diluted with EtOH, heated to boiling, treated with charcoal, filtered through Celite, and then allowed to stand at room temperature overnight. It was then chilled and the solid collected by filtration, washed with cold H2O and then ether, and dried in vacuo; yield 3.23 g (91%); mp 259°-260°; homogeneous according to TLC (19:1) and HPLC (23 H2O:2 MeCN); pmr; 3.7 (m, H4' and 2H5'), 4.15 (m, H2' and H3'), 5.1 (t, 5'-OH), 5.55 and 5.65 (2d, 2'-OH and 3'-OH), 6.14 (d, J1'2' 3Hz, H1'), 7.8 (broad s, NH2), 8.2 (s, H8); uv: pH 1--262 (13.2); ph 7, 13--261 (15.3).

1. customBCl3 gas (72.9) was bubbled in CH2Cl2 (610 ml) at 0°in a 2-l
2. custom, 3-necked flask equipped with a thermometer, magnetic stirrer, and addition funnel
3. temperaturethe stirred solution then cooled to -72° (dry ice-acetone)
4. customAfter a total reaction time of 23/4 hr, the cooling bath was removed
5. customthe solvent and gas removed in vacuo
6. dissolutionThe residue was dissolved in CH2Cl2 (40 ml)
7. customthe solution evaporated to dryness (six times)
8. customuntil a solid white residue is obtained
9. temperatureheated to boiling
10. filtrationfiltered through Celite
11. temperatureIt was then chilled
12. filtrationthe solid collected by filtration
13. washwashed with cold H2O
14. dry with materialether, and dried in vacuo