Phosphorus oxide (P4O10) → 5,7-Difluoro-3,4-dihydronaphthalen-1(2H)-one

HRID 1195832Notes

Reaction equation

HRID 1195832 reaction equation
O=P12OP3(OP(OP(O3)(O1)=O)(=O)O2)=O.[F:15][C:16]1[CH:21]=[C:20]([F:22])[CH:19]=[CH:18][C:17]=1[CH2:23][CH2:24][CH2:25][C:26]([OH:28])=O>>[F:15][C:16]1[CH:21]=[C:20]([F:22])[CH:19]=[C:18]2[C:17]=1[CH2:23][CH2:24][CH2:25][C:26]2=[O:28]

Participants

3

Reactant 2

HCID 14812Phosphorus oxide (P4O10)HCID 14368700110931-78-7

Product 1

HCID 143687015,7-Difluoro-3,4-dihydronaphthalen-1(2H)-one

Procedure

120 g of Polyphosphoric acid and 12 g of phosphorous pentoxide are stirred to homogeneity at 60°. 43 g of 4-(2,4-Difluorophenyl)butyric acid are added and the mixture stirred for 11/2 hours at 80°, poured onto ice-water and extracted with ether. The combined organic phases are washed with sodium carbonate solution and sodium chloride solution, dried, stirred with a little active charcoal and evaporated. The crude product can be purified by silica gel chromatography (eluant:hexane/ethylacetate=4/1) or vacuum sublimation at 0.65 mbar/100°, m.p. 89°-91°.

Workup

  1. additionpoured onto ice-water
  2. extractionextracted with ether
  3. washThe combined organic phases are washed with sodium carbonate solution and sodium chloride solution
  4. customdried
  5. stirringstirred with a little active charcoal
  6. customevaporated
  7. customThe crude product can be purified by silica gel chromatography (eluant:hexane/ethylacetate=4/1) or vacuum sublimation at 0.65 mbar/100°, m.p. 89°-91°

Sources & evidence

ORD record
ord-d8cbf651ed1344f0a7c5bfe843e99d64
Source dataset
uspto-grants-1992_05
Patent number
US05112851

Reaction notes

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