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MedKoo CAT#: 326872

CAS#: 51234-28-7

Description: Benoxaprofen, also known as Benoxaphen, is a non-steroidal anti-inflammatory drug developed by Eli Lilly and Company. Lilly suspended sales of Oraflex in 1982 after reports from the British government and the U.S. Food and Drug Administration (FDA) of adverse effects and deaths linked to the drug.

Price and Availability

Size Price Shipping out time Quantity
Inquire bulk and customized quantity

Pricing updated 2020-09-27. Prices are subject to change without notice.

Benoxaprofen is not in stock, may be available through custom synthesis. For cost-effective reason, minimum 1 gram order is requested. The product will be characterized by NMR, HPLC and MS analysis. Purity (HPLC) is usually >98%. CoA, QC data, MSDS will be provided when product is successfully made. The estimated lead time is 2-3 months. Please send email to to inquire quote.

Chemical Structure


Theoretical Analysis

MedKoo Cat#: 326872
Name: Benoxaprofen
CAS#: 51234-28-7
Chemical Formula: C16H12ClNO3
Exact Mass: 301.0506
Molecular Weight: 301.726
Elemental Analysis: C, 63.69; H, 4.01; Cl, 11.75; N, 4.64; O, 15.91

Synonym: Benoxaprofen; Benoxaphen. Compound 90459; LY-90459; NSC 299582; brand name Oraflex.

IUPAC/Chemical Name: 2-(2-(4-chlorophenyl)benzo[d]oxazol-5-yl)propanoic acid


InChi Code: InChI=1S/C16H12ClNO3/c1-9(16(19)20)11-4-7-14-13(8-11)18-15(21-14)10-2-5-12(17)6-3-10/h2-9H,1H3,(H,19,20)

SMILES Code: O=C(O)C(C)C1=CC=C(OC(C2=CC=C(Cl)C=C2)=N3)C3=C1

Technical Data

Solid powder

>98% (or refer to the Certificate of Analysis)

Shipping Condition:
Shipped under ambient temperature as non-hazardous chemical. This product is stable enough for a few weeks during ordinary shipping and time spent in Customs.

Storage Condition:
Dry, dark and at 0 - 4 C for short term (days to weeks) or -20 C for long term (months to years).

Soluble in DMSO

Shelf Life:
>2 years if stored properly

Drug Formulation:
This drug may be formulated in DMSO

Stock Solution Storage:
0 - 4 C for short term (days to weeks), or -20 C for long term (months).

HS Tariff Code:


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2: Okada K, Kanoh H, Mohri K. Effects of clofibric acid on the biliary excretion of benoxaprofen glucuronide and taurine conjugate in rats. Pharmazie. 2011 Oct;66(10):777-83. PubMed PMID: 22026160.

3: Dong JQ, Smith PC. Glucuronidation and covalent protein binding of benoxaprofen and flunoxaprofen in sandwich-cultured rat and human hepatocytes. Drug Metab Dispos. 2009 Dec;37(12):2314-22. doi: 10.1124/dmd.109.028944. Epub 2009 Sep 22. PubMed PMID: 19773537; PubMed Central PMCID: PMC2784705.

4: Dong JQ, Liu J, Smith PC. Role of benoxaprofen and flunoxaprofen acyl glucuronides in covalent binding to rat plasma and liver proteins in vivo. Biochem Pharmacol. 2005 Sep 15;70(6):937-48. PubMed PMID: 16046212.

5: Mohri K, Okada K, Benet LZ. Stereoselective taurine conjugation of (R)-benoxaprofen enantiomer in rats: in vivo and in vitro studies using rat hepatic mitochondria and microsomes. Pharm Res. 2005 Jan;22(1):79-85. PubMed PMID: 15771233.

6: Dong JQ, Etheridge AS, Smith PC. Effect of selective phase II enzyme inducers on glucuronidation of benoxaprofen in rats. Drug Metab Dispos. 1999 Dec;27(12):1423-8. PubMed PMID: 10570023.

7: Mohri K, Okada K, Benet LZ. Stereoselective metabolism of benoxaprofen in rats. Biliary excretion of benoxaprofen taurine conjugate and glucuronide. Drug Metab Dispos. 1998 Apr;26(4):332-7. PubMed PMID: 9531520.

8: Qiu Y, Burlingame AL, Benet LZ. Mechanisms for covalent binding of benoxaprofen glucuronide to human serum albumin. Studies By tandem mass spectrometry. Drug Metab Dispos. 1998 Mar;26(3):246-56. PubMed PMID: 9492388.

9: Dahms M, Spahn-Langguth H. Covalent binding of acidic drugs via reactive intermediates: detection of benoxaprofen and flunoxaprofen protein adducts in biological material. Pharmazie. 1996 Nov;51(11):874-81. PubMed PMID: 8985978.

10: Van Rensburg AJ, Theron AJ, Anderson R. Comparison of the pro-oxidative interactions of flunoxaprofen and benoxaprofen with human polymorphonuclear leucocytes in vitro. Agents Actions. 1991 Jul;33(3-4):292-9. PubMed PMID: 1950816.

11: Ayrton AD, Ioannides C, Parke DV. Induction of the cytochrome P450 I and IV families and peroxisomal proliferation in the liver of rats treated with benoxaprofen. Possible implications in its hepatotoxicity. Biochem Pharmacol. 1991 Jun 21;42(1):109-15. PubMed PMID: 2069584.

12: Brahams D. Late benoxaprofen claims. Lancet. 1991 Feb 23;337(8739):483-4. PubMed PMID: 1671484.

13: Lewis DF, Ioannides C, Parke DV. A retrospective study of the molecular toxicology of benoxaprofen. Toxicology. 1990 Dec 17;65(1-2):33-47. PubMed PMID: 2274968.

14: Becker RS, Chakravorti S, Yoon M. Photochemical and photophysical properties of piroxicam and benoxaprofen in various solvents. Photochem Photobiol. 1990 Feb;51(2):151-4. PubMed PMID: 2333332.

15: Artuso T, Bernadou J, Meunier B, Paillous N. DNA strand breaks photosensitized by benoxaprofen and other non steroidal antiinflammatory agents. Biochem Pharmacol. 1990 Feb 1;39(3):407-13. PubMed PMID: 2137692.

16: Frain-Bell W. A study of persistent photosensitivity as a sequel of the prior administration of the drug benoxaprofen. Br J Dermatol. 1989 Nov;121(5):551-62. PubMed PMID: 2532037.

17: Bradow G, Kan LS, Fenselau C. Studies of intramolecular rearrangements of acyl-linked glucuronides using salicylic acid, flufenamic acid, and (S)- and (R)-benoxaprofen and confirmation of isomerization in acyl-linked delta 9-11-carboxytetrahydrocannabinol glucuronide. Chem Res Toxicol. 1989 Sep-Oct;2(5):316-24. PubMed PMID: 2562425.

18: Brown KA, Ferrie J, Wilbourn B, Dumonde DC. Benoxaprofen inhibits the adhesion of human monocytes to cultured vascular endothelium. Agents Actions. 1989 Aug;28(1-2):115-20. PubMed PMID: 2782221.

19: Spahn H, Iwakawa S, Lin ET, Benet LZ. Procedures to characterize in vivo and in vitro enantioselective glucuronidation properly: studies with benoxaprofen glucuronides. Pharm Res. 1989 Feb;6(2):125-32. PubMed PMID: 2762212.

20: Ramakrishnan S, Macleod P, Tyrrell CJ. Acute radiation skin reaction and persistent photosensitivity after benoxaprofen. Lancet. 1988 Oct 15;2(8616):913. PubMed PMID: 2902367.