Pentoxifylline → (+/-)-Lisofylline

HRID 2200759Notes

Reaction equation

HRID 2200759 reaction equation
[CH3:1][C:2]([CH2:4][CH2:5][CH2:6][CH2:7][N:8]1[C:18](=[O:19])[N:17]([CH3:20])[C:12]2[N:13]=[CH:14][N:15]([CH3:16])[C:11]=2[C:9]1=[O:10])=[O:3].C(Cl)Cl.[BH4-].[Na+]>CO>[OH:3][CH:2]([CH3:1])[CH2:4][CH2:5][CH2:6][CH2:7][N:8]1[C:9](=[O:10])[C:11]2[N:15]([CH3:16])[CH:14]=[N:13][C:12]=2[N:17]([CH3:20])[C:18]1=[O:19]

Participants

5

Reactant 3

HCID 4740PentoxifyllineHCID 6344DichloromethaneHCID 4311764Sodium borohydride

Product 1

HCID 57782(+/-)-LisofyllineYield 71.5%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

Pentoxifylline (1.0 g, 3.59 mmol) was dissolved in methanol (20 mL) and DCM (3 mL) then cooled to 0° C. To the reaction was added sodium borohydride (0.41 g, 10.8 mmol) portionwise over 30 min. The reaction was stirred in the cold for 2 h; then it was evaporated to dryness under reduced pressure, diluted with water (100 mL) and extracted with ethyl acetate (3×75 mL). The combined extracts were dried with magnesium sulfate, filtered and the solvent was removed under reduced pressure to give 1-(5-hydroxyhexyl)-3,7-dimethyl-1H-purine-2,6(3H,7H)-dione (0.72 g, 71% yield) as a white solid. LCMS retention time=1.849 min and 98% purity, LCMS MH+ 281. 1H NMR (DMSO-d6) δ 8.00 (s, 1H), 4.31 (d, 1H, J=4 Hz), 3.88 (s, 3H), 3.84 (t, 2H, J=8 Hz), 3.51-3.59 (m, 1H), 1.45-1.56 (m, 2H), 1.25-1.37 (m, 4H), 1.02 ( d, 3H, J=4 Hz).

Workup

  1. customthen it was evaporated to dryness under reduced pressure
  2. additiondiluted with water (100 mL)
  3. extractionextracted with ethyl acetate (3×75 mL)
  4. dry with materialThe combined extracts were dried with magnesium sulfate
  5. filtrationfiltered
  6. customthe solvent was removed under reduced pressure

Sources & evidence

ORD record
ord-51224ce4d5df43398d60da562d272a2e
Source dataset
uspto-grants-2016_06
Patent number
US09359359B2

Reaction notes

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