Theobromine → 3,7-Dimethyl-1-(4-oxopentyl)purine-2,6-dione

HRID 648938Notes

Reaction equation

HRID 648938 reaction equation
[H-].[Na+].[NH:3]1[C:14](=[O:15])[C:13]2[N:11]([CH3:12])[CH:10]=[N:9][C:8]=2[N:6]([CH3:7])[C:4]1=[O:5].Cl[CH2:17][CH2:18][CH2:19][C:20](=[O:22])[CH3:21]>CN(C)C=O>[O:22]=[C:20]([CH2:19][CH2:18][CH2:17][N:3]1[C:14](=[O:15])[C:13]2[N:11]([CH3:12])[CH:10]=[N:9][C:8]=2[N:6]([CH3:7])[C:4]1=[O:5])[CH3:21]

Participants

5

Reactant 3

HCID 5429TheobromineHCID 24758Sodium hydrideHCID 799932-Pentanone, 5-chloro-

Product 1

HCID 104918413,7-Dimethyl-1-(4-oxopentyl)purine-2,6-dioneYield 11.2%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

A suspension of 80% sodium hydride in mineral oil (3 g; 0.1 moles) was added in small portions during 10 minutes, to a suspension of 18 g (0.1 moles) of theobromine in 400 ml of anhydrous dimethylformamide. The reaction mixture was heated to 95°-100° C. for 3 hours. Then 13.26 g (0.11 moles) of 5-chloro-2-pentanone were added, and the reaction mixture was maintained at 95°-100° C. for 20 hours more. After filtration, the filtrate was evaporated under reduced pressure, the residue was treated with 150 ml of water and the pH was adjusted to 13-14 with a 10% NaOH aqueous solution. The mixture was extracted with 3×80 ml of methylene chloride, the combined organic extracts were washed with 3×50 ml of water, dried over anhydrous sodium sulfate, filtered and evaporated under vacuum. 2.95 Grams (11.2%) of the title compound were obtained, melting at 109°-111° C., which was directly used in the next step. The 1H-NMR spectrum was consistent with the formula.

Workup

  1. temperatureThe reaction mixture was heated to 95°-100° C. for 3 hours
  2. temperaturethe reaction mixture was maintained at 95°-100° C. for 20 hours more
  3. filtrationAfter filtration
  4. customthe filtrate was evaporated under reduced pressure
  5. additionthe residue was treated with 150 ml of water
  6. extractionThe mixture was extracted with 3×80 ml of methylene chloride
  7. washthe combined organic extracts were washed with 3×50 ml of water
  8. dry with materialdried over anhydrous sodium sulfate
  9. filtrationfiltered
  10. customevaporated under vacuum

Sources & evidence

ORD record
ord-b4158bea30e749e8979263474d9dd674
Source dataset
uspto-grants-1988_04
Patent number
US04737502

Reaction notes

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