p-Toluenesulfonic acid → Acyclovir

To a mixture of acetic anhydride (1.2 ml) and p-toluenesulfonic acid (0.09 g) was added with stirring dioxolane (1.02 g) - caution, exothermic. The solution was allowed to cool for several minutes. Diacetylguanine (1.45 g) and dry toluene (9 ml) were added and the reaction mixture was stirred at reflux for 18 hr. and then allowed to cool to room temperature. The toluene was decanted off and the residue triturated several times with benzene. Methanol (10 ml) was added to the residue and evaporated under reduced pressure. To the residue was added 40% aqueous methylamine (10 ml) and the mixture heated on a steam bath for 20 min. The water and methylamine were removed under reduced pressure, ethanol (10 ml) was added and evaporated. The residue was thoroughly extracted with boiling methanol (700 ml total) and the combined extracts evaporated. The resulting solid was triturated with cold ethanol and then recrystallized from methanol to give 9-(2-hydroxyethoxymethyl)guanine (0.3 g).

1. temperatureto cool for several minutes
2. temperatureat reflux for 18 hr
3. customThe toluene was decanted off
4. customthe residue triturated several times with benzene
5. additionMethanol (10 ml) was added to the residue
6. customevaporated under reduced pressure
7. additionTo the residue was added 40% aqueous methylamine (10 ml)
8. temperaturethe mixture heated on a steam bath for 20 min
9. customThe water and methylamine were removed under reduced pressure, ethanol (10 ml)
10. additionwas added
11. customevaporated
12. extractionThe residue was thoroughly extracted with boiling methanol (700 ml total)
13. customthe combined extracts evaporated
14. customThe resulting solid was triturated with cold ethanol
15. customrecrystallized from methanol

ORD record

ord-bac7624945f849798d84013f303db8d7

Source dataset

uspto-grants-1979_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04146715