3,4-Dichlorobenzoic acid → 3,4-Dichloro-2-methylbenzoic acid

HRID 1492392Notes

Reaction equation

HRID 1492392 reaction equation
[CH2:1]([Li])CCC.[Cl:6][C:7]1[CH:8]=[C:9]([CH:13]=[CH:14][C:15]=1[Cl:16])[C:10]([OH:12])=[O:11].CI>O1CCCC1>[Cl:6][C:7]1[C:8]([CH3:1])=[C:9]([CH:13]=[CH:14][C:15]=1[Cl:16])[C:10]([OH:12])=[O:11]

Participants

5

Reactant 3

HCID 58173,4-Dichlorobenzoic acidHCID 6328Methyl iodideHCID 178418339Butyllithium

Product 1

HCID 105843563,4-Dichloro-2-methylbenzoic acid

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

n-Butyl lithium (2.5M in hexanes, 180 ml) was added during 1 hour to a stirred solution of 3,4-dichlorobenzoic acid (40.0 g) at -78° C. and stirring maintained at that temperature overnight. A solution of methyl iodide (72 ml) in tetrahydrofuran was then added during 1.5 hours and the mixture kept at -78° C. for 3 hours and allowed to warm to room temperature overnight. The solvent was evaporated and the mixture added to water, acidified (concentrated hydrochloric acid) and extracted (ethyl acetate). The extract was dried (magnesium sulphate), evaporated and triturated (ether) to give 3,4-dichloro-2-methylbenzoic acid (33.3 g) as a white solid, m.p. 177°-178° C.

Workup

  1. temperaturemaintained at that temperature overnight
  2. customThe solvent was evaporated
  3. additionthe mixture added to water
  4. extractionextracted (ethyl acetate)
  5. dry with materialThe extract was dried (magnesium sulphate)
  6. customevaporated
  7. customtriturated (ether)

Sources & evidence

ORD record
ord-dd024062847c4be5855e0e098498a274
Source dataset
uspto-grants-1994_12
Patent number
US05374606

Reaction notes

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