4156-16-5

Basic information

• Product Name: 2-Ethyl-5-phenylisoxazolium-3'-sulfonate
• Synonyms: NEPIS;N-ETHYL-5-PHENYLISOXAZOLIUM-3'-SULFONATE;WOODWARDS REAGENT K;WOODWARD'S REAGENT K;3-(2-ETHYL-5-ISOXAZOLIO)BENZENESULFONATE;2-ETHYL-5-PHENYLISOXAZOLIUM-3'-SULFONATE;2-ETHYL-5-PHENYLISOXAZOLIUM-3'-SULPHONATE;3-(2-Ethyl-5-isoxazolio)benzenesulphonate~NEPIS~Woodwards
• CAS NO: 4156-16-5
• Molecular Formula: C₁₁H₁₁NO₄S
• Molecular Weight: 253.27
• EINECS: 223-988-7
• Product Categories: Biochemistry;Condensation & Active Esterification;Coupling Reactions (Peptide Synthesis);Peptide Synthesis;Synthetic Organic Chemistry
• Mol File: 4156-16-5.mol
• Article Data: 0

Chemical Properties

• Melting Point: 216-219 °C (dec.)
• Boiling Point: °Cat760mmHg
• Flash Point: °C
• Appearance: white to pale pink crystals
• Density: 1.3854 (rough estimate)
• Refractive Index: 1.4790 (estimate)
• Storage Temp.: Store at RT.
• Merck: 10050
• BRN: 4149224
• CAS DataBase Reference: 2-Ethyl-5-phenylisoxazolium-3'-sulfonate(CAS DataBase Reference)
• NIST Chemistry Reference: 2-Ethyl-5-phenylisoxazolium-3'-sulfonate(4156-16-5)
• EPA Substance Registry System: 2-Ethyl-5-phenylisoxazolium-3'-sulfonate(4156-16-5)

Safety Data

• Hazard Codes: Xn
• Statements: 22
• WGK Germany: 3
• Hazardous Substances Data: 4156-16-5(Hazardous Substances Data)

Usage

Chemical Properties

white to off-white crystalline powder

Uses

Peptide-bond former.

Purification Methods

Crystallise the reagent from diethyl ether or ethyl acetate/pet ether. [Lamas et al. J Am Chem Soc 108 5543 1986.] It is best purified by dissolving in excess of aqueous N HCl and precipitating with Me2CO to give a white fluffy solid. [Woodward et al. Tetrahedron 22 Suppl 8 321 1966, Fieser & Fieser Reagents for Organic Synthesis 1 385, 2 198.]

Upstream product

• 98-86-2 acetophenone 
• 1006-67-3 5-phenylisoxazole 
• 368-39-8 triethyloxonium fluoroborate 
• 7145-48-4 Benzoylacetaldehyde ω-oxime 

Downstream Products

• 28047-15-6 N-phenylacetylglutamine 
• 72-69-5 3-(10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5-ylidene)-N-methyl-1-propanamine 
• 103383-42-2 3-[(Z)-3-Ethylamino-3-(2-hydroxy-ethylsulfanyl)-acryloyl]-benzenesulfonic acid 
• 103383-40-0 3-((Z)-3-Ethylamino-3-methylamino-acryloyl)-benzenesulfonic acid 
• 103383-39-7 3-(2-Ethylcarbamoyl-acetyl)-benzenesulfonic acid 
• 103383-38-6 3-(3-Ethylimino-acryloyl)-benzenesulfonic acid 
• 103383-43-3 3-{(E)-3-[4-((S)-2-Acetylamino-2-carbamoyl-ethyl)-phenoxy]-3-ethylamino-acryloyl}-benzenesulfonic acid 
• 103383-41-1 3-((Z)-3-Ethylamino-3-imidazol-1-yl-acryloyl)-benzenesulfonic acid