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Chemical product profile

HONGKUN / PRODUCT DIRECTORY

5-Bromo-2-chlorobenzoic acid | CAS 21739-92-4

A halogen-patterned aromatic acid used in published dapagliflozin routes, providing the 5-bromo-2-chloro aryl framework while its carboxyl group enables assembly of the downstream diaryl intermediate.

CAS21739-92-4
Molecular formulaC7H4BrClO2
Molecular weight235.46 g/mol

Product overview

Three substituents give 5-bromo-2-chlorobenzoic acid its route-specific identity: carboxyl at position 1, chlorine at position 2 and bromine at position 5. Published dapagliflozin processes use this arrangement to build a diaryl ketone and then a benzyl-substituted aromatic intermediate. The halogens have different roles as the route progresses, so a general halobenzoic-acid assay is not sufficient to qualify the starting material. Buyers should specify positional-isomer control and a chromatographic profile of related aromatic acids. Water and assay basis also matter when the next stage converts the acid to an activated acyl derivative.

Chemical identity

Chemical name
5-Bromo-2-chlorobenzoic acid
CAS number
21739-92-4
Molecular formula
C7H4BrClO2
Molecular weight
235.46 g/mol

Application context

In dapagliflozin process literature, 5-bromo-2-chlorobenzoic acid enters an acyl-activation and aryl-assembly sequence, leading to a 4-ethoxyphenyl-containing ketone and then the corresponding diarylmethane intermediate. Subsequent chemistry uses the brominated aromatic site in construction of the C-aryl glucoside framework. The original substitution pattern is therefore a structural requirement carried through several stages. Raw-material qualification should focus on whether the analytical method resolves alternative bromo/chloro positions and related aromatic acids. Where the material feeds acid-chloride chemistry, coordinate water, assay and any residual solvent criteria with that activation stage.

Chemistry and synthetic role

The molecule combines a carboxylic acid, an ortho aryl chloride and a bromine at C5. Acyl chemistry at the acid and later transformation at the brominated aryl site provide distinct synthetic handles.

Quality review

Resolve halogen positional isomers

Ask for a method that distinguishes the required 5-bromo-2-chloro arrangement from relevant positional analogues.

Distinguish acid and activated derivatives

Confirm the free carboxylic acid and the basis used for assay.

Set activation-stage requirements

Review related aromatic acids, water and residual solvent requirements against the following acyl-activation step.

Preparing a specification

Specify 5-bromo-2-chlorobenzoic acid, structural identity, chromatographic assay and relevant positional-isomer limits. State water and residual-solvent requirements for the next activation stage.

Packaging and storage

Packaging and net weight are agreed for the selected grade, order quantity and destination. Check the actual supplier SDS and label for storage and transport requirements.

Documentation

Request a batch COA, SDS and the analytical methods for the acceptance criteria below. Confirm which supporting chromatograms and identity data are available from the selected manufacturer.

Procurement questions

Does total halogen content confirm the correct intermediate?

No. It does not establish where bromine and chlorine are located on the ring.

Is this 5-bromo-2-chlorobenzoyl chloride?

No. The acid chloride is a separate downstream form with different composition and handling.

Why request the chromatographic impurity profile?

Closely related aromatic starting materials may carry their substitution patterns into downstream intermediates.

Technical sources
  1. PubChem CID 33127NCBI / PubChem
  2. 5-Bromo-2-chlorobenzoic AcidTCI
  3. Method for preparing 5-bromo-2-chlorobenzoic acid as raw material in hypoglycemic drug synthesisEuropean patent EP4389733A1
  4. Process for the preparation of 4-bromo-1-chloro-2-(4-ethoxybenzyl)benzeneWIPO patent WO2015063726A1