131179-95-8

Basic information

• Product Name: Efaproxiral
• Synonyms: 2-(4-(((3,5-dimethylanilino)carbonyl)methyl)phenoxy)-2-methylpropionic acid;2-[4-(3,5-Dimethylphenylcarbamoylmethyl)phenoxy]-2-methylpropionic acid;Efaproxiral;Efaproxiral free acid;faproxiral;EFAPROXIRALUM
• CAS NO: 131179-95-8
• Molecular Formula: C₂₀H₂₃NO₄
• Molecular Weight: 341.4
• EINECS: 1806241-263-5
• Product Categories: Amines;Aromatics;Intermediates & Fine Chemicals;Pharmaceuticals
• Mol File: 131179-95-8.mol
• Article Data: 4

Chemical Properties

• Melting Point: 48-50°C
• Boiling Point: 554.5 °C at 760 mmHg
• Flash Point: 289.2 °C
• Appearance: /
• Density: 1.202g/cm³
• Vapor Pressure: 3.93E-13mmHg at 25°C
• Refractive Index: 1.597
• Storage Temp.: Refrigerator
• Solubility: DMSO (Slightly), Methanol (Slightly)
• PKA: 3.26±0.10(Predicted)
• CAS DataBase Reference: Efaproxiral(CAS DataBase Reference)
• NIST Chemistry Reference: Efaproxiral(131179-95-8)
• EPA Substance Registry System: Efaproxiral(131179-95-8)

Safety Data

• Hazardous Substances Data: 131179-95-8(Hazardous Substances Data)

Usage

Description

Efaproxiral is an allosteric hemoglobin (Hb) modifier that reduces the affinity of Hb for oxygen, increasing the diffusion of oxygen from blood to tissue. In isolated human whole blood, efaproxiral (1.75 mM) increases the partial pressure of oxygen at which Hb is 50% saturated (p50) from 26.75 to 38.63 mm Hg and decreases the percent oxyhemoglobin (Hb-O2) saturation from 48 to 33.8% at a partial oxygen pressure (pO2) of 26 mm Hg. Efaproxiral (150 mg/kg) increases tumor pO2 from 5.2 to 13.1 mm Hg 30 minutes after administration in a RIF-1 mouse fibrosarcoma flank tumor model. Efaproxiral (100 μM) enhances radiation-induced cytotoxicity in EMT6 mouse breast cancer cells grown under hypoxic conditions and increases radiosensitization and inhibits tumor growth in a hypoxic Lewis lung tumor mouse model when administered at a dose of 100 mg/kg. It also increases the running capacity of normal mice and mice with left coronary artery (LCA) ligation-induced myocardial infarction (MI) when administered at a dose of 150 mg/kg.

Chemical Properties

Off-White to Tan Solid

Uses

Allosteric modifier of hemoglobin (HB). Binds in the central water cavity of the Hb molecule causing a conformational change such that bound oxygen is released more readily. Antineoplastic adjunct (radiosensitizer).

InChI:InChI=1/C20H23NO4/c1-13-9-14(2)11-16(10-13)21-18(22)12-15-5-7-17(8-6-15)25-20(3,4)19(23)24/h5-11H,12H2,1-4H3,(H,21,22)(H,23,24)

Upstream product

• 67-66-3 chloroform 
• 131179-77-6 N-(3,5-dimethylphenyl)-4-hydroxyphenylacetamide 
• 67-64-1 acetone 
• 1019680-83-1 tert-butyl 2-(4-(2-(3,5-dimethylphenylamino)-2-oxoethyl)phenoxy)-2-methylpropanoate 
• 37859-23-7 2-(p-hydroxyphenyl)acetyl chloride 
• 108-69-0 3,5-dimethylaminoaniline 
• 156-38-7 4-hydroxyphenylacetate 
• 2052-01-9 2-bromo-2-methylpropionic acid 

Relevant articles and documents

Trimethylaluminium mediated amide bond formation in a continuous flow microreactor as key to the synthesis of rimonabant and efaproxiral

A safe, functional-group-tolerant and high-throughput version of the trimethylaluminium mediated amide bond formation reaction has been developed in a microreactor system; rimonabant and efaproxiral were prepared to illustrate the utility of the method. The Royal Society of Chemistry.

Mass spectrometric characterization of efaproxiral (RSR13) and its implementation into doping controls using liquid chromatography-atmospheric pressure ionization-tandem mass spectrometry

Efaproxiral (2-[4-[[(3,5-dimethylanilino)carbonyl]methyl]phenoxyl]-2- methylpropionic acid, formerly referred to as RSR13) is prohibited in sports according to the World Anti-Doping Agency (WADA). The drug as well as structurally related compounds and a stable isotope-labeled derivative have been synthesized to elucidate the fragmentation pathway of efaproxiral, using electrospray ionization (ESI) and tandem mass spectrometry by employing a novel linear ion trap - orbitrap hybrid mass spectrometer - in positive and negative ionization modes. The elimination of 2-methyl acrylic acid (-86 u) has been identified as a major fragmentation process in both charge states. Negative ionization and collision-induced dissociation (CID) caused an additional release of carbon dioxide (-44 u), and positive ionization the loss of formic acid (-46 u). Efaproxiral was incorporated into an existing screening procedure for doping controls using solid-phase extraction (SPE) followed by liquid chromatography-tandem mass spectrometry, enabling a limit of detection of 2.5 ng/ml and interday precisions ranging from 7.9 to 13.0%. Copyright