Citrate → [(2S,3S,5R)-5-[2-amino-6-(cyclobutoxy)purin-9-yl]-3-azido-tetrahydrofuran-2-yl]methanol

Temperature

50 °C

To 800 mL of an aqueous pH 6.0, 50 mM citrate buffer, prepared as described in Example 2c, was added 2-amino-6-(cyclobutoxy)-9H-purine (0.164 g, 0.8 mmol) and 3'-azido-3'-deoxythymidine (1.069 g, 4.0 mmol). Solution was achieved by heating the mixture at 50° C. with sonication. A sample was removed as a control. A 40 mL solution of trans-N-deoxyribosylase with an activity of 1500 units/mL was added. The reaction was heated at 50° C. Five days later 0.164 g, 0.8 mmol, of 2-amino-6-cyclobutoxypurine was added to the reaction. Ten days after the reaction was started, another 0.164 g, 0.8 mmol, of 2-amino-6-cyclobutoxypurine and 0.428 g, 1.6 mmol, of 3'-azido-3'-deoxythymidine were added to the reaction. Twenty-one days after the reaction was started, 0.164 g, 0.8 mmol, of 2-amino-6-cyclobutoxypurine was added to the reaction. The reaction was stopped after twenty-six days by heating to 80° C. to precipitate the enzyme. After chilling to 0° C. the mixture was filtered. The aqueous filtrate was extracted with ethyl acetate (3 times) to remove the product. The combined ethyl acetate fractions were dried with magnesium sulfate, filtered and the solvent removed in vacuo to give a foam. The foam was chromatographed on basic alumina grade 1 eluted with chloroform/methanol (95.5, v/v). The product containing fractions were combined and the solvent removed in vacuo to give the product as a foam, 0.334 g, in 32% yield.

1. customwith sonication
2. customA sample was removed as a control
3. additionA 40 mL solution of trans-N-deoxyribosylase with an activity of 1500 units/mL was added
4. temperatureThe reaction was heated at 50° C
5. additionFive days later 0.164 g, 0.8 mmol, of 2-amino-6-cyclobutoxypurine was added to the reaction
6. customTen days
7. additionanother 0.164 g, 0.8 mmol, of 2-amino-6-cyclobutoxypurine and 0.428 g, 1.6 mmol, of 3'-azido-3'-deoxythymidine were added to the reaction
8. customTwenty-one days
9. addition0.164 g, 0.8 mmol, of 2-amino-6-cyclobutoxypurine was added to the reaction
10. waitThe reaction was stopped after twenty-six days
11. temperatureby heating to 80° C.
12. customto precipitate the enzyme
13. temperatureAfter chilling to 0° C. the mixture
14. filtrationwas filtered
15. extractionThe aqueous filtrate was extracted with ethyl acetate (3 times)
16. customto remove the product
17. dry with materialThe combined ethyl acetate fractions were dried with magnesium sulfate
18. filtrationfiltered
19. customthe solvent removed in vacuo
20. customto give a foam
21. customThe foam was chromatographed on basic alumina grade 1
22. washeluted with chloroform/methanol (95.5
23. additionThe product containing fractions
24. customthe solvent removed in vacuo

ORD record

ord-60d6e7f75bd24b28900c5e22b26b2c55

Source dataset

uspto-grants-1992_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05153318