4,5-difluoro-2-methyl-7-pentyl-8,9-dihydro-7H-furo[3,2-f]chromene → 4,5-difluoro-2-methyl-7-pentyl-1,7,8,9-tetrahydro-2H-furo[3,2-f]chromene

HRID 2244854Notes

Reaction equation

HRID 2244854 reaction equation
[F:1][C:2]1[C:11]([F:12])=[C:10]2[C:5]([CH2:6][CH2:7][CH:8]([CH2:13][CH2:14][CH2:15][CH2:16][CH3:17])[O:9]2)=[C:4]2[CH:18]=[C:19]([CH3:21])[O:20][C:3]=12>C1COCC1.[Pd]>[F:1][C:2]1[C:11]([F:12])=[C:10]2[C:5]([CH2:6][CH2:7][CH:8]([CH2:13][CH2:14][CH2:15][CH2:16][CH3:17])[O:9]2)=[C:4]2[CH2:18][CH:19]([CH3:21])[O:20][C:3]=12

Participants

4

Reactant 1

HCID 592152484,5-difluoro-2-methyl-7-pentyl-8,9-dihydro-7H-furo[3,2-f]chromene

Product 1

HCID 592152464,5-difluoro-2-methyl-7-pentyl-1,7,8,9-tetrahydro-2H-furo[3,2-f]chromene

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 8028TetrahydrofuranSolvent

Procedure

2.0 g (7.51 mmol) of 4,5-difluoro-2-methyl-7-pentyl-8,9-dihydro-7H-furo-[3,2-f]chromene are hydrogenated for 18 h at elevated temperature in THF using elemental hydrogen in the presence of Pd/C (5% Pd). The reaction soln. is concentrated to dryness, and the residue is purified by column chromatography (SiO2, n-heptane:MTBE=4:1). Further purification is carried out by recrystallisation from ethanol at 5° C., giving 4,5-difluoro-2-methyl-7-pentyl-1,7,8,9-tetrahydro-2H-furo[3,2-f]chromene as a colourless solid having an m.p. of 76° C. (Δ∈=−8.2).

Workup

  1. concentrationis concentrated to dryness
  2. customthe residue is purified by column chromatography (SiO2, n-heptane:MTBE=4:1)
  3. customFurther purification
  4. customis carried out by recrystallisation from ethanol at 5° C.

Sources & evidence

ORD record
ord-ec761fecd5f4436d9aefd0799f3fce2e
Source dataset
uspto-grants-2010_03
Patent number
US07678929B2

Reaction notes

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