Cloxacillin

Also known as: Cloxacillin, BRL 1621, Orbenin, Tegopen, Cloxacilline, MCIPC, (2S,5R,6R)-6-[[[3-(2-Chlorophenyl)-5-methyl-4-isoxazolyl]carbonyl]amino]-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylic acid, 6-[3-(o-Chlorophenyl)-5-methyl-4-isoxazolecarboxamido]-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylic acid, Methocillins, Syntarpen, BRN 0157438, EINECS 200-514-7, Cloxacillin (base and/or unspecified salts)

Cloxacillin (CAS 61-72-3) is a compound in the Organohalogen Compounds category listed in the Jingsj chemical database. It has the molecular formula C19H18ClN3O5S and a molecular weight of 435.881 g/mol. Key properties include a boiling point of 689.7±55.0 °C at 760 mmHg, a density of 1.6±0.1 g/cm3 and a flash point of 370.9±31.5 °C. No supplier offers are currently listed; request a quote. Record last updated Aug 21, 2026.

CAS No.: 61-72-3
Jingsj CID: J-49142-0
Molecular Formula: C₁₉H₁₈ClN₃O₅S
Molecular Weight: 435.881 g/mol
Category: Organohalogen Compounds
Last updated: 8/21/2026

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Physicochemical Properties

Boiling Point	689.7±55.0 °C at 760 mmHg
Density	1.6±0.1 g/cm3
Flash Point	370.9±31.5 °C
Exact Mass	435.065582
PSA	138.04000
LogP	2.53
Vapor Pressure	0.0±2.3 mmHg at 25°C
Refractive Index	1.685

Activity & Biological Data

Target	IC50: 0.04 µM (β-lactamase from wild type A.caviae), 0.3 µM (β-lactamase from mutant A.caviae)[3].
Additional Information	[1]. Zhou H, et al. The combination of cloxacillin, thioridazine and tetracycline protects mice against Staphylococcus aureus peritonitis by inhibiting α-Hemolysin-induced MAPK/NF-κB/NLRP3 activation. Int J Biol Macromol. 2022 Feb 15;198:1-10. [2]. Bergmann B, et al. Antibiotics with Interleukin-15 Inhibition Reduce Joint Inflammation and Bone Erosions but Not Cartilage Destruction in Staphylococcus aureus-Induced Arthritis. Infect Immun. 2018 Apr 23;86(5):e00960-17. [3]. Lupiola-Gómez PA, et al. Group 1 beta-lactamases of Aeromonas caviae and their resistance to beta-lactam antibiotics. Can J Microbiol. 2003 Mar;49(3):207-15.

Target

IC50: 0.04 µM (β-lactamase from wild type A.caviae), 0.3 µM (β-lactamase from mutant A.caviae)[3].

Additional Information

[1]. Zhou H, et al. The combination of cloxacillin, thioridazine and tetracycline protects mice against Staphylococcus aureus peritonitis by inhibiting α-Hemolysin-induced MAPK/NF-κB/NLRP3 activation. Int J Biol Macromol. 2022 Feb 15;198:1-10. [2]. Bergmann B, et al. Antibiotics with Interleukin-15 Inhibition Reduce Joint Inflammation and Bone Erosions but Not Cartilage Destruction in Staphylococcus aureus-Induced Arthritis. Infect Immun. 2018 Apr 23;86(5):e00960-17. [3]. Lupiola-Gómez PA, et al. Group 1 beta-lactamases of Aeromonas caviae and their resistance to beta-lactam antibiotics. Can J Microbiol. 2003 Mar;49(3):207-15.

Frequently Asked Questions

What is the CAS number of Cloxacillin?

The CAS number of Cloxacillin is 61-72-3.

What are the molecular formula and molecular weight of Cloxacillin?

Cloxacillin has molecular formula C19H18ClN3O5S and molecular weight 435.881 g/mol.

What are the upstream and downstream products of Cloxacillin?

For Cloxacillin, Upstream Products: 2-Chlorobenzaldehyde oxime, methyl 3-(2-chlorophenyl)-5-methylisoxazole-4-carboxylate, alpha,2-Dichlorobenzaldoxime.

Data compiled from public chemical databases such as PubChem and supplier catalogs; supplier offers are provided by suppliers.

Last updated: 8/21/2026

How to cite: Jingsj. "Cloxacillin (CAS 61-72-3)". Jingsj Chemical Database. https://www.jingsj.com/compound/J-49142-0 (accessed 2026-11-07).

Data for reference only; verify product details with suppliers before purchase.