反应详情

2',3'-Dideoxycytidine (2.4 mmoles, 0.5 g, Pharmacia, Piscataway, N.J.), dimethylaminopyridine (0.178 mmoles, 21.7 mg), triethylamine (6.34 mmoles, 0.886 ml) and propionic anhydride (1 ml, Aldrich Chemicals, Milwaukee, Wis.) were suspended in 50 ml of acetonitrile. The reaction was allowed to proceed at room temperature for 24 hours after which time 10 ml of methanol were added. The solvent from the reaction was removed under vacuum and the residue chromatographed on a column of silica gel, 5×40 cm. The mobile phase was chloroform/methanol (9:1; v/v). The product containing fractions were combined and the solvent removed under vacuum. The residue was dissolved with water and 320 units of porcine liver esterase type 1 (EC 3.1.1.1, Sigma Chemicals, St. Louis, Mo.) added. After 24 hours at room temperature the pH was adjusted to 7.0 from 5.5 and an additional 320 units of esterase added. One day later the reaction was complete and the solvent removed under vacuum. The residue was chromatographed on a silica gel column (5×40 cm) and eluted with chloroform/methanol (9:1, v/v). Product containing fractions were combined and the solvent removed in vacuo yielding 0.408 g of 2',3'-dideoxy-N4 -pivaloylcytidine that contained 0.5 equivalents of water.

1. customThe solvent from the reaction was removed under vacuum
2. customthe residue chromatographed on a column of silica gel, 5×40 cm
3. additionThe product containing fractions
4. customthe solvent removed under vacuum
5. dissolutionThe residue was dissolved with water and 320 units of porcine liver esterase type 1 (EC 3.1.1.1, Sigma Chemicals, St. Louis, Mo.)
6. additionadded
7. waitAfter 24 hours at room temperature the pH was adjusted to 7.0 from 5.5
8. additionan additional 320 units of esterase added
9. customOne day
10. customthe solvent removed under vacuum
11. customThe residue was chromatographed on a silica gel column (5×40 cm)
12. washeluted with chloroform/methanol (9:1
13. additionProduct containing fractions
14. customthe solvent removed in vacuo