Potassium Carbonate → 2-(4,4-Difluorobut-3-enyl)thiobenzoxazole

HRID 2399851Notes

Reaction equation

HRID 2399851 reaction equation
[SH:1][C:2]1[O:3][C:4]2[CH:10]=[CH:9][CH:8]=[CH:7][C:5]=2[N:6]=1.CC1C=CC(S(O[CH2:22][CH2:23][CH:24]=[C:25]([F:27])[F:26])(=O)=O)=CC=1.C(=O)([O-])[O-].[K+].[K+]>CC(C)=O>[F:26][C:25]([F:27])=[CH:24][CH2:23][CH2:22][S:1][C:2]1[O:3][C:4]2[CH:10]=[CH:9][CH:8]=[CH:7][C:5]=2[N:6]=1

Participants

5

Reactant 3

HCID 11430Potassium CarbonateHCID 11666101HCID 11666101, compound2×HCID 1784182821,3-benzoxazole-2-thiol

Product 1

HCID 544327612-(4,4-Difluorobut-3-enyl)thiobenzoxazoleYield 120.6%

Reagents, catalysts & solvents 1

HCID 180AcetoneSolvent

Procedure

2-Mercaptobenzoxazole (4.79 g) was added to a solution of 1,1-difluorobut-1-en-4-yl 4-methylbenzenesulphonate (6.4 g) in acetone (200 cm3) containing potassium carbonate (5.06 g). The mixture was heated to reflux overnight (17 hr) and gc used to confirm that the 1,1-difluorobut-1-en-4-yl 4-methylbenzenesulphonate had been consumed and the product had formed. The reaction mass was allowed to cool and was filtered through a plug of High-Flo filter aid to remove insoluble inorganic material. The solid material was washed with ethyl acetate and the combined organic portions evaporated under reduced pressure to give 7.1 g of a brown oily residue. This material was fractionated by eluting through a bed of silica using hexane/ethyl acetate (40:1 by volume) as solvent to give the required product as a colourless oil (5.4 g, 92% based on the sulphonate); M+ =241;

Workup

  1. temperatureThe mixture was heated
  2. temperatureto reflux overnight (17 hr)
  3. customhad been consumed
  4. customthe product had formed
  5. temperatureto cool
  6. filtrationwas filtered through a plug of High-Flo
  7. filtrationfilter aid
  8. customto remove insoluble inorganic material
  9. washThe solid material was washed with ethyl acetate
  10. customthe combined organic portions evaporated under reduced pressure

Sources & evidence

ORD record
ord-b6450033e10b401f8f4941f595b57e41
Source dataset
uspto-grants-1995_09
Patent number
US05451681

Reaction notes

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