1,2,4-Trichlorobenzene → 3,6-Dichlorosalicylic acid

HRID 971919

Reaction equation

HRID 971919 reaction equation
C[O:2][C:3]1[C:11]([Cl:12])=[CH:10][CH:9]=[C:8]([Cl:13])[C:4]=1[C:5]([OH:7])=[O:6].ClC1C=CC(Cl)=CC=1Cl.ClC1C(Cl)=C(Cl)C=CC=1.ClC1C=CC(Cl)=CC=1O.[OH-].[Na+].C1(O)C=CC=CC=1.C(=O)=O>CO>[OH:2][C:3]1[C:11]([Cl:12])=[CH:10][CH:9]=[C:8]([Cl:13])[C:4]=1[C:5]([OH:7])=[O:6]

Participants

9

Reactant 7

HCID 131,2,4-TrichlorobenzeneHCID 662,5-DichlorophenolHCID 280Carbon DioxideHCID 996PhenolHCID 3030Dicamba2×HCID 68951,2,3-TrichlorobenzeneHCID 14798Sodium Hydroxide

Product 1

HCID 188443,6-Dichlorosalicylic acid

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

The compound 2-methoxy-3,6-dichlorobenzoic acid is a valuable herbicide and is used in commerce for the control of a variety of undesirable vegetation. The prior art discloses in U.S. Pat. No. 3,013,054 that the 2-methoxy-3,6-dichlorobenzoic acid is prepared from 1,2,4-trichlorobenzene in a three-stage process. The trichlorobenzene is first converted to 2,5-dichlorophenol with methanol and sodium hydroxide. The phenol is then treated with carbon dioxide under pressure to yield 2-hydroxy-3,6-dichlorobenzoic acid. The hydroxy acid is then methylated with dimethyl sulfate or methyl chloride to yield the desired product.

Sources & evidence

ORD record
ord-46bcb6126a8742e8990ca55f52b9e759
Source dataset
uspto-grants-1979_07
Patent number
US04161611

Linked notes

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