Ammonium Chloride → O-methyl 2,2-bis(fluoromethyl)-6-trifluoromethyl-2H-1-benzopyran-4-carbothioate

HRID 1282437Notes

Reaction equation

HRID 1282437 reaction equation
Br[C:2]1[C:7]2[CH:8]=[C:9]([C:12]([F:15])([F:14])[F:13])[CH:10]=[CH:11][C:6]=2[O:5][C:4]([CH2:18][F:19])([CH2:16][F:17])[CH:3]=1.C([Li])CCC.[CH3:25][O:26][C:27](=[S:30])OC.[Cl-].[NH4+]>COC(C)(C)C>[F:17][CH2:16][C:4]1([CH2:18][F:19])[CH:3]=[C:2]([C:27](=[S:30])[O:26][CH3:25])[C:7]2[CH:8]=[C:9]([C:12]([F:15])([F:14])[F:13])[CH:10]=[CH:11][C:6]=2[O:5]1

Participants

6

Reactant 4

HCID 25517Ammonium ChlorideHCID 136867O,O'-Dimethyl monothiocarbonateHCID 184244094-bromo-2,2-bis(fluoromethyl)-6-trifluoromethyl-2H-1-benzopyranHCID 178418339Butyllithium

Product 1

HCID 18424412O-methyl 2,2-bis(fluoromethyl)-6-trifluoromethyl-2H-1-benzopyran-4-carbothioateYield 56.2%

Reagents, catalysts & solvents 1

HCID 15413tert-Butyl methyl etherSolvent

Procedure

An amount (65 mg) of 4-bromo-2,2-bis(fluoromethyl)-6-trifluoromethyl-2H-1-benzopyran was dissolved in t-butyl methyl ether (2 ml); to the solution, 1.69 M n-butyllithium (0.11 ml) was added at −70° C. under a nitrogen atmosphere and the mixture was stirred for 10 minutes. Then, dimethoxycarbon sulfide (39 mg) was slowly added dropwise to the reaction mixture, which was stirred for 30 minutes at −70° C. To the reaction mixture, a saturated aqueous solution of ammonium chloride was added, followed by extraction with hexane/ethyl acetate (3/1). The resulting organic layers were washed with a saturated aqueous solution of sodium chloride, dried with anhydrous sodium sulfate and concentrated under reduced pressure; the resulting residue was subjected to silica gel column chromatography (eluent; hexane/ethyl acetate=2/1) to give the titled compound (36 mg) as a colorless oil.

Workup

  1. stirringwas stirred for 30 minutes at −70° C
  2. extractionfollowed by extraction with hexane/ethyl acetate (3/1)
  3. washThe resulting organic layers were washed with a saturated aqueous solution of sodium chloride
  4. dry with materialdried with anhydrous sodium sulfate
  5. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-6610257918724e68916919d809860701
Source dataset
uspto-grants-2002_09
Patent number
US06455708B1

Reaction notes

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