Ketotifen

Also known as: 4,9-Dihydro-4-(1-methyl-4-piperidinylidene)-10H-benzo[4,5]cyclohepta[1,2-b]thiophen-10-one, HC 20-511, Ketotifene, Ketotifeno, Ketotifenum, Zaditen

Ketotifen (CAS 34580-13-7) is a compound in the Ketones category listed in the Jingsj chemical database. It has the molecular formula C19H19NOS and a molecular weight of 309.42500 g/mol. Key properties include a melting point of 152-153ºC, a boiling point of 488.9ºC at 760mmHg, a density of 1.236g/cm3 and a flash point of 249.5ºC. No supplier offers are currently listed; request a quote. Record last updated Aug 21, 2026.

CAS No.: 34580-13-7
Jingsj CID: J-1958797-4
Molecular Formula: C₁₉H₁₉NOS
Molecular Weight: 309.42500 g/mol
Category: Ketones
Last updated: 8/21/2026

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Physicochemical Properties

Melting Point	152-153ºC
Boiling Point	488.9ºC at 760mmHg
Density	1.236g/cm3
Flash Point	249.5ºC
Exact Mass	309.11900
PSA	48.55000
LogP	3.95230

Activity & Biological Data

Target	Histamine 1, SARS-CoV-2, Influenza virus[1][3][4]
Additional Information	[1]. Klooker TK, et al. The mast cell stabiliser ketotifen decreases visceral hypersensitivity and improves intestinal symptoms in patients with irritable bowel syndrome. Gut. 2010 Sep;59(9):1213-21. [2]. Zhang H, et al. Advances in the discovery of exosome inhibitors in cancer. J Enzyme Inhib Med Chem. 2020;35(1):1322-1330. [3]. Kiani P, et al. In Vitro Assessment of the Antiviral Activity of Ketotifen, Indomethacin and Naproxen, Alone and in Combination, against SARS-CoV-2. Viruses. 2021 Mar 26;13(4):558. [4]. Enkirch T, et al. Identification and in vivo Efficacy Assessment of Approved Orally Bioavailable Human Host Protein-Targeting Drugs With Broad Anti-influenza A Activity. Front Immunol. 2019 Jun 5;10:1097. [5]. Pinke KH, et al. Calming Down Mast Cells with Ketotifen: A Potential Strategy for Multiple Sclerosis Therapy? Neurotherapeutics. 2020 Jan;17(1):218-234.

Target

Histamine 1, SARS-CoV-2, Influenza virus[1][3][4]

Additional Information

[1]. Klooker TK, et al. The mast cell stabiliser ketotifen decreases visceral hypersensitivity and improves intestinal symptoms in patients with irritable bowel syndrome. Gut. 2010 Sep;59(9):1213-21. [2]. Zhang H, et al. Advances in the discovery of exosome inhibitors in cancer. J Enzyme Inhib Med Chem. 2020;35(1):1322-1330. [3]. Kiani P, et al. In Vitro Assessment of the Antiviral Activity of Ketotifen, Indomethacin and Naproxen, Alone and in Combination, against SARS-CoV-2. Viruses. 2021 Mar 26;13(4):558. [4]. Enkirch T, et al. Identification and in vivo Efficacy Assessment of Approved Orally Bioavailable Human Host Protein-Targeting Drugs With Broad Anti-influenza A Activity. Front Immunol. 2019 Jun 5;10:1097. [5]. Pinke KH, et al. Calming Down Mast Cells with Ketotifen: A Potential Strategy for Multiple Sclerosis Therapy? Neurotherapeutics. 2020 Jan;17(1):218-234.

Frequently Asked Questions

What is the CAS number of Ketotifen?

The CAS number of Ketotifen is 34580-13-7.

What are the molecular formula and molecular weight of Ketotifen?

Ketotifen has molecular formula C19H19NOS and molecular weight 309.42500 g/mol.

What are the upstream and downstream products of Ketotifen?

For Ketotifen, Upstream Products: 10-methoxy-4-(1-methylpiperidin-4-yl)-4H-benzo[4,5]cyclohepta[1,2-b]thiophene-4-ol, 10-Methoxy-4H-benzo[4,5]cyclohepta[1,2-b]thiophen-4-one, 4-Chloro-1-methylpiperidine.

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. "Ketotifen (CAS 34580-13-7)". Jingsj Chemical Database. https://www.jingsj.com/compound/J-1958797-4 (accessed 2026-11-09).

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