Potassium Carbonate → (4,4-Difluorobut-3-enylthio)-3-methyl-1,2,4-thiadiazole

HRID 725009Notes

Reaction equation

HRID 725009 reaction equation
[CH3:1][C:2]1[NH:6][C:5](=[S:7])[S:4][N:3]=1.CC1C=CC(S(O[CH2:19][CH2:20][CH:21]=[C:22]([F:24])[F:23])(=O)=O)=CC=1.C(=O)([O-])[O-].[K+].[K+]>CC(C)=O>[F:23][C:22]([F:24])=[CH:21][CH2:20][CH2:19][S:7][C:5]1[S:4][N:3]=[C:2]([CH3:1])[N:6]=1

Participants

5

Reactant 3

HCID 11430Potassium CarbonateHCID 11666101HCID 11666101, compoundHCID 1784347993-methyl-1,2,4-thiadiazole-5-thiol

Product 1

HCID 21850474(4,4-Difluorobut-3-enylthio)-3-methyl-1,2,4-thiadiazoleYield 32%

Reagents, catalysts & solvents 1

HCID 180AcetoneSolvent

Procedure

To a solution of 3-methyl-1,2,4-thiadiazole-5(4H)-thione (1.2 g) in acetone (100 cm3) was added 4,4-difluorobut-3-enyl 4-methylbenzenesulfonate (2.4 g) and potassium carbonate (1.2 g) and the mixture was refluxed for 4 hours after which tlc indicated complete consumption of starting material. The reaction was poured into ethyl acetate and water and the layers separated. The aqueous layer was extracted with ethyl acetate and the combined organic layers were dried (MgSO4). The solution of product was then filtered and evaporated under reduced pressure to give a brown oil which was purified by flash chromatography (silica, 7% ethyl acetate in hexane) to give 5-(4,4-difluorobut-3-enylthio)-3-methyl-1,2,4-thiadiazole as a brown oil (0.645 g). M+ =222; 1H NMR: δ 2.56(2H,br q); 2.63 (3H,s); 3.30(2H,t); 4.30(1H,m).

Workup

  1. temperaturethe mixture was refluxed for 4 hours after which tlc
  2. customconsumption of starting material
  3. additionThe reaction was poured into ethyl acetate and water
  4. customthe layers separated
  5. extractionThe aqueous layer was extracted with ethyl acetate
  6. dry with materialthe combined organic layers were dried (MgSO4)
  7. filtrationThe solution of product was then filtered
  8. customevaporated under reduced pressure
  9. customto give a brown oil which
  10. customwas purified by flash chromatography (silica, 7% ethyl acetate in hexane)

Sources & evidence

ORD record
ord-cfc021c995cc4e58abbc88a90627f13a
Source dataset
uspto-grants-1998_01
Patent number
US05705516

Reaction notes

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