Oseltamivir phosphate

Also known as: Tamiflu, GS-4104/002, Ro 64-0796/002, Ethyl (3R,4R,5S)-4-acetamido-5-amino-3-(pentan-3-yloxy)cyclohex-1-ene-1-carboxylate phosphate, Ethyl (3R,4R,5S)-4-acetamido-5-amino-3-(3-pentanyloxy)-1-cyclohexene-1-carboxylate phosphate (1:1), 1-Cyclohexene-1-carboxylic acid, 4-(acetylamino)-5-amino-3-(1-ethylpropoxy)-, ethyl ester, (3R,4R,5S)-, phosphate (1:1), Oseltamivir phosphate (Tamiflu), Ro-64-0796/002, (3R,4R,5S)-ethyl 4-acetamido-5-amino-3-(pentan-3-yloxy)cyclohex-1-enecarboxylate phosphate, Oseltamivir phosphate (200 mg)

Oseltamivir phosphate (CAS 204255-11-8) is a compound in the Organic Acids category listed in the Jingsj chemical database. It has the molecular formula C16H31N2O8P and a molecular weight of 410.400 g/mol. Key properties include a melting point of 196-198°C, a boiling point of 473.3ºC at 760 mmHg, a density of 1.08g/cm3 and a flash point of 240ºC. No supplier offers are currently listed; request a quote. Record last updated Aug 21, 2026.

CAS No.: 204255-11-8
Jingsj CID: J-1960844-2
Molecular Formula: C₁₆H₃₁N₂O₈P
Molecular Weight: 410.400 g/mol
Category: Organic Acids
Last updated: 8/21/2026

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Physicochemical Properties

Melting Point	196-198°C
Boiling Point	473.3ºC at 760 mmHg
Density	1.08g/cm3
Flash Point	240ºC
Exact Mass	410.181793
PSA	178.22000
LogP	1.44800
Storage Conditions	-20°C Freezer

Activity & Biological Data

Target	Influenza A and B[1]
Additional Information	[1]. Huang H, et al. Transplacental transfer of Oseltamivir phosphate and its metabolite Oseltamivir carboxylate using the ex vivo human placenta perfusion model in Chinese Hans population. J Matern Fetal Neonatal Med. 2016 Aug 8:1-5. [2]. de Oliveira JT, et al. Anti-influenza neuraminidase inhibitor Oseltamivir phosphate induces canine mammary cancer cell aggressiveness. PLoS One. 2015 Apr 7;10(4):e0121590. [3]. Li P, et al. A Simple and Robust Approach for Evaluation of Antivirals Using a Recombinant Influenza Virus Expressing Gaussia Luciferase. Viruses. 2018 Jun 13;10(6). pii: E325.

Target

Influenza A and B[1]

Additional Information

[1]. Huang H, et al. Transplacental transfer of Oseltamivir phosphate and its metabolite Oseltamivir carboxylate using the ex vivo human placenta perfusion model in Chinese Hans population. J Matern Fetal Neonatal Med. 2016 Aug 8:1-5. [2]. de Oliveira JT, et al. Anti-influenza neuraminidase inhibitor Oseltamivir phosphate induces canine mammary cancer cell aggressiveness. PLoS One. 2015 Apr 7;10(4):e0121590. [3]. Li P, et al. A Simple and Robust Approach for Evaluation of Antivirals Using a Recombinant Influenza Virus Expressing Gaussia Luciferase. Viruses. 2018 Jun 13;10(6). pii: E325.

Customs & Trade Information

HS Code	2924299090
Summary	2924299090. other cyclic amides (including cyclic carbamates) and their derivatives; salts thereof. VAT:17.0%. Tax rebate rate:13.0%. . MFN tariff:6.5%. General tariff:30.0%

Frequently Asked Questions

What is the CAS number of Oseltamivir phosphate?

The CAS number of Oseltamivir phosphate is 204255-11-8.

What are the molecular formula and molecular weight of Oseltamivir phosphate?

Oseltamivir phosphate has molecular formula C16H31N2O8P and molecular weight 410.400 g/mol.

What are the upstream and downstream products of Oseltamivir phosphate?

For Oseltamivir phosphate, Upstream Products: Oseltamivir, Ethyl (3R,4R,5S)-4-acetamido-5-azido-3-(1-ethylpropoxy)-1-cyclohexene-1-carboxylate, Phosphoric acid; Downstream Products: Oseltamivir.

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. "Oseltamivir phosphate (CAS 204255-11-8)". Jingsj Chemical Database. https://www.jingsj.com/compound/J-1960844-2 (accessed 2026-11-06).

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