Skip to product details

Chemical product profile

HONGKUN / PRODUCT DIRECTORY

6,7-Difluoro-8-methoxyquinolone carboxylic acid | CAS 112811-72-0

A free-acid quinolone building block in gatifloxacin synthesis, carrying N-cyclopropyl and 8-methoxy groups before installation of the amine-containing fragment; acid content and residual ester guide selection for the receiving step.

CAS112811-72-0
Molecular formulaC14H11F2NO4
Molecular weight295.24 g/mol

Product overview

The free carboxylic acid distinguishes this quinolone nucleus from the companion ethyl ester, CAS 112811-71-9. It already contains N-cyclopropyl, 6,7-difluoro and 8-methoxy substitution and is used in published gatifloxacin preparation before installation of the later amine-containing fragment. The name Q-acid should be accompanied by CAS 112811-72-0 and the complete structure to specify this stage precisely. Qualification should establish acid content and resolve residual ester and relevant ring-related compounds. Acid-base assay and HPLC composition provide complementary information. State the quantitative reporting basis and any water or solvent correction used for charging, together with the identity and related-substances methods required by the receiving process.

Chemical identity

Chemical name
1-Cyclopropyl-6,7-difluoro-8-methoxy-4-oxo-1,4-dihydroquinoline-3-carboxylic acid
CAS number
112811-72-0
Molecular formula
C14H11F2NO4
Molecular weight
295.24 g/mol

Application context

In published gatifloxacin preparation, this free acid supplies the preassembled quinolone nucleus for installation of the later amine-containing fragment. The 6,7-difluoro and 8-methoxy pattern must remain explicit alongside the acid designation. Qualification should resolve residual ethyl ester and relevant ring-related compounds, and distinguish acid assay from chromatographic area purity. State any water or solvent correction used to calculate the quantity charged into the next step.

Chemistry and synthetic role

The molecule contains both a 3-carboxylic acid and a 4-oxo quinolone unit. Its C7 fluorinated site participates in the substitution logic of the documented drug route; the complete nucleus is required to define that role.

Quality review

Verify free-acid form

Differentiate the acid from its ethyl ester and any counterion-containing form proposed under a shorthand name.

Retain the full fluorination pattern

Confirm 6,7-difluoro and 8-methoxy identity rather than using total fluorine as a substitute for structure.

Compare assay methods correctly

Titration and HPLC answer different questions. Agree an acid-content basis and the separation of relevant ester or substituted quinolone species.

Preparing a specification

Request the free acid under CAS 112811-72-0 with a specified assay basis and chromatographic related-substances method. State whether residual ethyl ester, water or residual solvents need individual limits for your route.

Packaging and storage

Confirm packaging format, net weight and transport arrangements for the selected grade, order quantity and destination. Request the applicable SDS and label to establish storage and handling conditions.

Documentation

Request the proposed specification, batch COA and current SDS. Confirm availability of the analytical methods and batch evidence relevant to the intended process. Ask for the acid-content calculation and chromatographic discrimination from the companion ester.

Procurement questions

Is Q-acid already gatifloxacin?

No. The later amine-bearing substitution is absent from this precursor.

Can the ethyl ester be supplied against this CAS?

No. The ethyl ester is a separate compound with CAS 112811-71-9.

Does titration replace related-substances testing?

No. Acid content does not by itself establish the identity and proportions of related organic compounds.

Technical sources
  1. PubChem CID 7019465: identity properties and CAS synonymsNCBI / PubChem
  2. C4205: 1-Cyclopropyl-6,7-difluoro-8-methoxy-4-oxoquinoline-3-carboxylic acidTokyo Chemical Industry
  3. WO2005047262A1: Crystalline form of gatifloxacinWIPO publication via Google Patents