Sulfuric Acid → 3-Methyl-7-(5-oxohexyl)-1-propyl-3,7-dihydro-1H-purine-2,6-dione
Reaction equation
[CH3:1][N:2]1[C:10]2[N:9]=[CH:8][N:7]([CH2:11][CH2:12][CH2:13][CH2:14][C:15](=[O:17])[CH3:16])[C:6]=2[C:5](=[O:18])[NH:4][C:3]1=[O:19].[OH-].[Na+].[CH3:22][CH2:23][CH2:24]Br.S(=O)(=O)(O)O>O.CO>[CH2:22]([N:4]1[C:5](=[O:18])[C:6]2[N:7]([CH2:11][CH2:12][CH2:13][CH2:14][C:15](=[O:17])[CH3:16])[CH:8]=[N:9][C:10]=2[N:2]([CH3:1])[C:3]1=[O:19])[CH2:23][CH3:24]Participants
Procedure
A suspension of 79.2 g of 3-methyl-7-(5-oxohexyl)-xanthine in a mixture of 120 g of water and 72 g of methanol is brought into solution by the addition of 18 g of sodium hydroxide at about 60° C. 55.5 g of n-propyl bromide are then added. After boiling under reflux for 24 hours, the reaction mixture is treated with 1 ml of concentrated sulphuric acid and cooled. Unreacted 3-methyl-7-(5-oxohexyl)-xanthine is filtered off and the alcohol is distilled off in vacuo. The remaining solution is made alkaline with 4 ml of 50% sodium hydroxide solution and extracted with 350 ml of methylene chloride. 1-n-Propyl-3-methyl-7-(5-oxohexyl)-xanthine with a melting point of 76°-78° C. is obtained in 85% yield from the residue of the methylene chloride solution by recrystallisation from isopropanol. The solubility of the product in ethanol, dimethyl sulphoxide and dimethylformamide is over 10%.
Workup
- temperatureunder reflux for 24 hours
- temperaturecooled
- filtrationUnreacted 3-methyl-7-(5-oxohexyl)-xanthine is filtered off
- distillationthe alcohol is distilled off in vacuo
- extractionextracted with 350 ml of methylene chloride
Sources & evidence
- ORD record
- ord-994fedd3393e4ebbb1a51de9e0a72523
- Source dataset
- uspto-grants-1981_09
- Patent number
- US04289776
Reaction notes
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