Potassium Carbonate → HCID 20157775, compound

HRID 2290251Notes

Reaction equation

HRID 2290251 reaction equation
[CH2:1]([N:5]1[C:13]2[N:12]=[CH:11][N:10]([CH3:14])[C:9]=2[C:8](=[O:15])[NH:7][C:6]1=[O:16])[CH2:2][CH2:3][CH3:4].BrCCCC=C.C(=O)([O-])[O-].[K+].[K+].Cl[C:30]1[CH:35]=CC=[C:32]([C:36]([O:38]O)=O)[CH:31]=1>CN(C)C=O>[CH2:1]([N:5]1[C:13]2[N:12]=[CH:11][N:10]([CH3:14])[C:9]=2[C:8](=[O:15])[N:7]([CH2:35][CH2:30][CH2:31][CH:32]2[O:38][CH2:36]2)[C:6]1=[O:16])[CH2:2][CH2:3][CH3:4]

Participants

6

Reactant 4

HCID 11430Potassium CarbonateHCID 70297m-Chloroperbenzoic acidHCID 707041-Pentene, 5-bromo-HCID 20157771HCID 20157771, compound

Product 1

HCID 20157775HCID 20157775, compoundYield 84.7%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Conditions

Temperature
100 °C

Procedure

33.3 g (0.15 mole) of 3-butyl-7-methylxanthine, 24.3 g (0.16 mole) of 1-bromo-4-pentene and 22.1 g (0.16 mole) of potassium carbonate in 500 ml of dimethylformamide were heated with stirring at 100° C. for 15 hours. After cooling down, the reaction mixture was evaporated under reduced pressure, the residue was taken up in methylene chloride, filtered and the filtrate was extracted by shaking with 1N sodium hydroxide solution, the organic phase was washed with water to neutrality, dried over sodium sulfate and solvent was removed in a rotary evaporator. This produced 42.2 g (97% of theory) of crude, crystalline 3-butyl-7-methyl-1-(4-pentenyl)xanthine ##STR32## which was dissolved in 550 ml of chloroform, 35.6 g (0.175 mole) of 3-chloroperbenzoic acid (85% pure) were added and the mixture, after covering with an atmosphere of nitrogen, was stirred at room temperature for 67 hours. Extraction by shaking with 10% strength sodium dithionite solution until disappearance of the iodine-starch reaction, washing, initially with 10% strength sodium bicarbonate solution and then with water, drying over sodium sulfate and evaporation under reduced pressure provided 37.7 g (84.7% of theory) of crude 3-butyl-1-(4,5-epoxypentyl)-7-methylxanthine, ##STR33## which was subjected to hydrolytic opening of the oxirane ring without intermediate purification. For this purpose, the 37.7 g of epoxide was dissolved in a mixture of 200 ml of tetrahydrofuran and 135 ml of water, and 0.61 ml of perchloric acid (70% strength) was added dropwise with stirring within about 10 minutes at room temperature. After stirring at room temperature for 14 hours, the mixture was neutralized with saturated sodium bicarbonate solution and evaporated under reduced pressure. The remaining oily crude product (100% of theory) could be purified by column chromatography on silica gel with chloroform/methanol (volume ratio 10/1) as the eluting agent and subsequent recrystallization from ethyl acetate with the addition of petroleum ether at the boiling point until cloudy.

Workup

  1. temperatureAfter cooling down
  2. customthe reaction mixture was evaporated under reduced pressure
  3. filtrationfiltered
  4. extractionthe filtrate was extracted
  5. stirringby shaking with 1N sodium hydroxide solution
  6. washthe organic phase was washed with water to neutrality
  7. dry with materialdried over sodium sulfate and solvent
  8. customwas removed in a rotary evaporator
  9. dissolutionThis produced 42.2 g (97% of theory) of crude, crystalline 3-butyl-7-methyl-1-(4-pentenyl)xanthine ##STR32## which was dissolved in 550 ml of chloroform
  10. stirringwas stirred at room temperature for 67 hours
  11. extractionExtraction
  12. stirringby shaking with 10% strength sodium dithionite solution until disappearance of the iodine-starch reaction
  13. washwashing, initially with 10% strength sodium bicarbonate solution
  14. dry with materialwith water, drying over sodium sulfate and evaporation under reduced pressure

Sources & evidence

ORD record
ord-3713a4ceaf3742e89e6ffffd288628e1
Source dataset
uspto-grants-1986_10
Patent number
US04616020

Reaction notes

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