Bromine → 1-(1-Bromo-2-keto-5-pentyl)-3,7-dimethylxanthine

HRID 648939Notes

Reaction equation

HRID 648939 reaction equation
BrBr.[O:3]=[C:4]([CH2:6][CH2:7][CH2:8][N:9]1[C:18](=[O:19])[C:17]2[N:16]([CH3:20])[CH:15]=[N:14][C:13]=2[N:12]([CH3:21])[C:10]1=[O:11])[CH3:5].C(=O)(O)[O-].[Na+].[Br:27]C(CCN1C(=O)C2N(C)C=NC=2N(C)C1=O)C(=O)C>CO.O>[Br:27][CH2:5][C:4](=[O:3])[CH2:6][CH2:7][CH2:8][N:9]1[C:18](=[O:19])[C:17]2[N:16]([CH3:20])[CH:15]=[N:14][C:13]=2[N:12]([CH3:21])[C:10]1=[O:11]

Participants

7

Reactant 4

HCID 24408BromineHCID 516892Sodium BicarbonateHCID 104918413,7-Dimethyl-1-(4-oxopentyl)purine-2,6-dioneHCID 886237931-(3-Bromo-2-keto-5-pentyl)-3,7-dimethylxanthine

Product 1

HCID 537173951-(1-Bromo-2-keto-5-pentyl)-3,7-dimethylxanthine

Reagents, catalysts & solvents 2

HCID 887MethanolSolventHCID 962WaterSolvent

Procedure

4.93 Grams (0.031 moles) of bromine were added to a solution of 7.3 g (0.0276 moles) of compound (a) in 100 ml of methanol, at 10° C. After stirring for 15 hours at room temperature, the reaction mixture volume was concentrated to 30 ml under reduced pressure, then 60 ml of water, and 3 drops of conc. sulphuric acid were added. The mixture was stirred at room temperature for 4 hours, in order to hydrolyze any dimethylketals formed by reaction with methanol. After dilution with 50 ml of water, the pH of the mixture was adjusted to 8-9, by addition of a 10% sodium bicarbonate aqueous solution, the mixture was extracted with 3×50 ml of methylene chloride, washed with water, dried on anhydrous sodium sulfate, filtered and evaporated under vacuum. 8.3 Grams of compound were obtained, which, by TLC and NMR analysis, showed to be impure by the presence of the 1-(3-bromo-2-keto-5-pentyl)-3,7-dimethylxanthine regioisomer. The crude compound was directly used for the next step.

Workup

  1. concentrationthe reaction mixture volume was concentrated to 30 ml under reduced pressure
  2. addition60 ml of water, and 3 drops of conc. sulphuric acid were added
  3. stirringThe mixture was stirred at room temperature for 4 hours, in order
  4. customformed by reaction with methanol
  5. extractionthe mixture was extracted with 3×50 ml of methylene chloride
  6. washwashed with water
  7. dry with materialdried on anhydrous sodium sulfate
  8. filtrationfiltered
  9. customevaporated under vacuum
  10. custom8.3 Grams of compound were obtained

Sources & evidence

ORD record
ord-6990a76abe094640983ed1b010798e41
Source dataset
uspto-grants-1988_04
Patent number
US04737502

Reaction notes

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