Description

Besifloxacin (3S)-Isomer CAS NO 141388-77-4 is the optically pure (S)-enantiomer of the broad-spectrum fluoroquinolone antibiotic besifloxacin. This specific stereoisomer is of critical importance for pharmaceutical research and development, particularly in the formulation of novel ophthalmic solutions targeting bacterial conjunctivitis. It is primarily required by pharmaceutical manufacturers, advanced research institutions, and fine chemical suppliers focused on developing enantiomerically pure active pharmaceutical ingredients (APIs).

Application

• Active Pharmaceutical Ingredient (API) Synthesis: As the key chiral building block for the production of besifloxacin hydrochloride, the active component in prescription ophthalmic suspensions.
• Ophthalmic Drug Development: Primary raw material for R&D and manufacturing of sterile eye drops and solutions designed to treat bacterial eye infections.
• Microbiological Research: Used as a reference standard in studies investigating the mechanism of action, resistance, and spectrum of activity of fluoroquinolone antibiotics.
• Chiral Chemistry Studies: Serves as a model compound in research focused on stereoselective synthesis, chiral separation techniques, and enantiomer-specific biological activity.
• Pharmaceutical Intermediates: Employed in the synthesis of more complex drug molecules where the besifloxacin pharmacophore is incorporated.
• Quality Control & Analytical Standards: Utilized as a high-purity certified reference material (CRM) for HPLC, LC-MS, and other analytical methods in pharmaceutical QC laboratories.

Basic Information

Item	Detail
Product Name	Besifloxacin (3S)-Isomer
CAS No.	141388-77-4
Molecular Formula	C19H21ClFN3O3
Molecular Weight	393.84 g/mol
Synonyms	(3S)-7-[(3R)-3-Amino-2,3,4,5,6,7-hexahydro-1H-azepin-1-yl]-8-chloro-1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-3-quinolinecarboxylic Acid; (S)-Besifloxacin; Besifloxacin S-Isomer; (3S)-Besifloxacin; 8-Chloro-1-cyclopropyl-7-((3R,11aS)-3-amino-1,2,3,4,5,6,7,11a-octahydroazepino[1,2-a]quinolin-9-yl)-6-fluoro-4-oxo-1,4-dihydroquinoline-3-carboxylic Acid (S-enantiomer)
EINECS	Contact for details

Quality Control

Our Besifloxacin (3S)-Isomer is manufactured under strict quality management systems. Each batch undergoes comprehensive analytical testing, including chiral purity assay by HPLC, to ensure it meets stringent specifications for pharmaceutical R&D use. A detailed Certificate of Analysis (COA) is provided with every shipment, documenting identity, purity, and impurity profiles.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry place at a controlled room temperature (15-25°C). Due to its hygroscopic nature, the container must be kept tightly sealed in a dry environment to prevent moisture absorption. For long-term storage, consider desiccants or inert atmosphere packaging.

Specification

Item	Specification
Appearance	White to off-white powder
Identification (IR)	Conforms to reference spectrum
Identification (HPLC)	Retention time matches reference standard
Assay (HPLC)	≥98.5%
Chiral Purity (Enantiomeric Excess)	≥99.0%
Related Substances (HPLC)	Total impurities ≤1.5% Any single impurity ≤0.5%
Residual Solvents (GC)	Complies with ICH Q3C guidelines
Water Content (KF)	≤1.0%
Heavy Metals	≤20 ppm

Note: Specifications can be tailored. Please contact us for the detailed technical data sheet of a specific grade.