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Chemical product profile

HONGKUN / PRODUCT DIRECTORY

3-Methoxy-2-methylbenzoic acid | CAS 55289-06-0

An aromatic acyl building block with adjacent methyl and methoxy substituents, appearing in pharmaceutical and agrochemical intermediate chemistry with hydroxyl and ester-related impurities worth distinguishing.

CAS55289-06-0
Molecular formulaC9H10O3
Molecular weight166.17 g/mol

Product overview

The benzoic acid group in this molecule is flanked by a methyl substituent at position 2, with methoxy at position 3. The 1,2,3 arrangement determines the aromatic fragment delivered to subsequent acyl chemistry. Material identity should therefore distinguish positional isomers as well as the corresponding hydroxy acid and methyl ester. These related structures may require separate chromatographic attention even when total acid content is satisfactory.

Chemical identity

Chemical name
3-Methoxy-2-methylbenzoic acid
CAS number
55289-06-0
Molecular formula
C9H10O3
Molecular weight
166.17 g/mol

Application context

Process patents describe 3-methoxy-2-methylbenzoic acid as an intermediate in pharmaceutical and agrochemical synthesis and demonstrate conversion to its benzoyl chloride. That conversion supplies the same substituted aromatic acyl fragment for subsequent elaboration. Purchasing priorities include free-acid content and control of hydroxy or ester-related species that do not provide the same protected aromatic functionality. Use the intended downstream derivative and analytical method to set acceptance criteria for the actual route.

Chemistry and synthetic role

The methoxy group is an aryl ether; the free carboxylic acid is the site used for acyl-derivative formation. The ring methyl group remains a separate substituent.

Quality review

Substitution pattern

Confirm 2-methyl/3-methoxy identity rather than another methoxymethylbenzoic acid isomer.

Hydroxy analogue

Include 3-hydroxy-2-methylbenzoic acid in route-specific impurity review where relevant.

Ester versus free acid

Distinguish methyl ester carryover from free-acid assay and define the water basis.

Preparing a specification

Specify the 2-methyl/3-methoxy acid, quantitative assay and positional-isomer, hydroxy-analogue and ester criteria relevant to the acylation route.

Packaging and storage

Confirm container compatibility, closure and net weight for the selected grade and destination. Follow the actual supplier SDS and batch label for storage and transport.

Documentation

Request the batch COA, SDS and analytical methods covering the agreed purchasing specification. Confirm which supporting chromatograms and application-specific records are available from the selected manufacturer.

Procurement questions

Does methoxy mean that the carboxyl group is methyl-esterified?

No. Methoxy is attached to the aromatic ring; the carboxyl remains a free acid.

Why review the hydroxy analogue?

Replacing methoxy with hydroxyl changes the aromatic functionality transferred downstream.

Can it supply the corresponding benzoyl fragment?

Published process chemistry converts it to 3-methoxy-2-methylbenzoyl chloride.

Technical sources
  1. PubChem CAS identity lookupNCBI / PubChem
  2. 3-Methoxy-2-methylbenzoic AcidTCI
  3. Preparation of 3-alkoxy-2-methylbenzoic acidsPatent applicants / Google Patents