Reaction equation
[CH:1]1[N:5]([CH2:6][O:7][CH2:8][CH2:9][OH:10])[C:4]2[N:11]=[C:12]([NH2:16])[N:13]=[C:14]([OH:15])[C:3]=2[N:2]=1.CN(C)C=O.[C:22](Cl)(=[O:27])[CH2:23][CH2:24][CH2:25][CH3:26]>CN(C)C1C=CN=CC=1.CO.O>[C:22]([O:10][CH2:9][CH2:8][O:7][CH2:6][N:5]1[CH:1]=[N:2][C:3]2[C:14](=[O:15])[NH:13][C:12]([NH2:16])=[N:11][C:4]1=2)(=[O:27])[CH2:23][CH2:24][CH2:25][CH3:26]Participants
Conditions
- Temperature
- 5 °C
Procedure
A mixture of acyclovir prepared according to UK Patent No. 1523865 (3.11 moles), 4-dimethylaminopyridine (4.91 moles) and dimethylformamide (5.6 L) was stirred under nitrogen with heating on steam bath to give a homogeneous solution. On cooling to room temperature valeryl chloride (4.91 moles) was added dropwise while the temperature was maintained at 20°-25° C. Progress of the reaction was monitored by HPLC (Partisil ODS-3, methanol:water 50:50) and the reaction was terminated when the level of residual acyclovir was less than 0.5% (AUC). The mixture was cooled to 5° C., filtered and the cake was washed with dimethylformamide (200 ml). The combined filtrates were diluted with absolute ethanol (1 L), stirred for two hours at ambient temperature and concentrated to a thick oil. Methanol (16 L) was added and the resulting suspension was refluxed for 1.5 hours, cooled to 5° C. and filtered. The crude product was washed with methanol (200 mL) and dried under vacuum to constant weight to give 819 g (85.1% yield) of 9-(2-valeryloxyethoxymethyl) guanine, M.p. 215°-217° C.
Workup
- customprepared
- temperaturewith heating on steam bath
- customto give a homogeneous solution
- additionwas added dropwise while the temperature
- temperaturewas maintained at 20°-25° C
- customthe reaction was terminated when the level of residual acyclovir
- filtrationfiltered
- washthe cake was washed with dimethylformamide (200 ml)
- additionThe combined filtrates were diluted with absolute ethanol (1 L)
- concentrationconcentrated to a thick oil
- additionMethanol (16 L) was added
- temperaturethe resulting suspension was refluxed for 1.5 hours
- temperaturecooled to 5° C.
- filtrationfiltered
- washThe crude product was washed with methanol (200 mL)
- customdried under vacuum to constant weight
Sources & evidence
- ORD record
- ord-f7df73bf6c844dc890797c17757fe548
- Source dataset
- uspto-grants-1992_01
- Patent number
- US05079252
Linked notes
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