1,2-Difluoro-3-prop-2-ynyloxybenzene → 7,8-Difluorochroman

HRID 1873303Notes

Reaction equation

HRID 1873303 reaction equation
[F:1][C:2]1[C:11]([F:12])=[C:10]2[C:5]([CH:6]=[CH:7][CH2:8][O:9]2)=[CH:4][CH:3]=1.FC1C=CC=C(OCC#C)C=1F>C1COCC1.[Pd]>[F:1][C:2]1[C:11]([F:12])=[C:10]2[C:5]([CH2:6][CH2:7][CH2:8][O:9]2)=[CH:4][CH:3]=1

Participants

5

Reactant 2

HCID 592152381,2-Difluoro-3-prop-2-ynyloxybenzeneHCID 592152877,8-difluoro-2H-chromene

Product 1

HCID 591673237,8-Difluorochroman

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 8028TetrahydrofuranSolvent

Procedure

A mixture of 7,8-difluoro-2H-chromene and 1,2-difluoro-3-prop-2-ynyloxybenzene (43.2 g) is hydrogenated at RT for 1 h in 430 ml of THF in the presence of Pd/C (5% of Pd). The batch is evaporated to dryness, and the crude product is purified by column chromatography (SiO2, n-pentane: 1-chlorobutane=4:1), giving pure 7,8-difluorochroman as a pale-yellowish liquid.

Workup

  1. customThe batch is evaporated to dryness
  2. customthe crude product is purified by column chromatography (SiO2, n-pentane: 1-chlorobutane=4:1)

Sources & evidence

ORD record
ord-b963f135725b47d0b355aa9d03ed52d0
Source dataset
uspto-grants-2012_11
Patent number
US08303844B2

Reaction notes

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