Hydrochloric Acid → 2-Chloro-3-fluorobenzoic acid

HRID 1741807Notes

Reaction equation

HRID 1741807 reaction equation
C([Li])CCC.CN(C)CCN(C)C.[F:14][C:15]1[CH:16]=[C:17]([CH:21]=[CH:22][CH:23]=1)[C:18]([OH:20])=[O:19].[Cl:24]C(Cl)(Cl)C(Cl)(Cl)Cl.Cl>CCCCCC.O1CCCC1>[Cl:24][C:16]1[C:15]([F:14])=[CH:23][CH:22]=[CH:21][C:17]=1[C:18]([OH:20])=[O:19]

Participants

8

Reactant 5

HCID 313Hydrochloric AcidHCID 6214HexachloroethaneHCID 8037N,N,N',N'-TetramethylethylenediamineHCID 99683-Fluorobenzoic AcidHCID 178418339Butyllithium

Product 1

HCID 3026202-Chloro-3-fluorobenzoic acidYield 69.6%

Reagents, catalysts & solvents 2

HCID 8028TetrahydrofuranSolvent2×HCID 8058HexaneSolvent

Conditions

Temperature
10 °C

Procedure

A solution of 1.6N n-butyl lithium in hexane (294 ml) was added to 71 ml of tetramethyl ethylene diamine (TMEDA) in tetrahydrofuran at -70° C. under an inert atmosphere. 3-Fluorobenzoic acid (30 g) in tetrahydrofuran was added and the mixture was stirred for one hour. Hexachloroethane (111.5 g) was added and the reaction mixture was stirred for two hours at -70° C. The reaction mixture was allowed to warm to 10° C. and acidified (to pH 1) with 3M hydrochloric acid solution, extracted with diethyl ether, dried (anhydrous magnesium sulphate) and concentrated to give a solid that was recrystallised from heptane/ethyl acetate to give 2-chloro-3-fluorobenzoic acid (26 g).

Workup

  1. stirringthe reaction mixture was stirred for two hours at -70° C
  2. extractionextracted with diethyl ether
  3. dry with materialdried (anhydrous magnesium sulphate)
  4. concentrationconcentrated
  5. customto give a solid
  6. customthat was recrystallised from heptane/ethyl acetate

Sources & evidence

ORD record
ord-77d3a553c9e64232af7508bd1c6a9404
Source dataset
uspto-grants-1994_08
Patent number
US05334753

Reaction notes

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