{"product_id":"oxyma-pure-cas-3849-21-6","title":"Oxyma | CAS 3849-21-6 | ≥95%","description":"\u003cdiv style=\"margin-bottom: 28px;\"\u003e\n\u003cdiv style=\"background: #002147; padding: 10px 20px; margin-bottom: 0;\"\u003e\n\u003ch3 style=\"margin: 0; font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 0.70em; font-weight: bold; letter-spacing: 0.12em; text-transform: uppercase; color: #fff;\"\u003eTechnical Specifications\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003ctable style=\"width: 100%; border-collapse: collapse; font-size: 0.95em; border: 1px solid #e4e8f0; border-top: none; font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 9px 16px; font-weight: 600; color: #002147; width: 200px; border-bottom: 1px solid #e4e8f0; background: #f7f8fb; font-size: 0.95em; vertical-align: top;\"\u003eCAS Number\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 16px; color: #333; border-bottom: 1px solid #e4e8f0;\"\u003e3849-21-6\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 9px 16px; font-weight: 600; color: #002147; width: 200px; border-bottom: 1px solid #e4e8f0; background: #f7f8fb; font-size: 0.95em; vertical-align: top;\"\u003eEC \/ EINECS Number\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 16px; color: #333; border-bottom: 1px solid #e4e8f0;\"\u003e223-351-3\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 9px 16px; font-weight: 600; color: #002147; width: 200px; border-bottom: 1px solid #e4e8f0; background: #f7f8fb; font-size: 0.95em; vertical-align: top;\"\u003eMDL Number\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 16px; color: #333; border-bottom: 1px solid #e4e8f0;\"\u003eMFCD00002112\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 9px 16px; font-weight: 600; color: #002147; width: 200px; border-bottom: 1px solid #e4e8f0; background: #f7f8fb; font-size: 0.95em; vertical-align: top;\"\u003eSMILES\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 16px; color: #333; border-bottom: 1px solid #e4e8f0; word-break: break-all;\"\u003eCCOC(=O)C(=NO)C#N\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 9px 16px; font-weight: 600; color: #002147; width: 200px; border-bottom: 1px solid #e4e8f0; background: #f7f8fb; font-size: 0.95em; vertical-align: top;\"\u003eInChI\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 16px; color: #333; border-bottom: 1px solid #e4e8f0; word-break: break-all;\"\u003eInChI=1S\/C5H6N2O3\/c1-2-10-5(8)4(3-6)7-9\/h9H,2H2,1H3\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 9px 16px; font-weight: 600; color: #002147; width: 200px; border-bottom: 1px solid #e4e8f0; background: #f7f8fb; font-size: 0.95em; vertical-align: top;\"\u003eInChIKey\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 16px; color: #333; border-bottom: 1px solid #e4e8f0; word-break: break-all;\"\u003eLCFXLZAXGXOXAP-UHFFFAOYSA-N\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 9px 16px; font-weight: 600; color: #002147; width: 200px; border-bottom: 1px solid #e4e8f0; background: #f7f8fb; font-size: 0.95em; vertical-align: top;\"\u003ePubChem CID\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 16px; color: #333; border-bottom: 1px solid #e4e8f0;\"\u003e6399078\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 9px 16px; font-weight: 600; color: #002147; width: 200px; border-bottom: 1px solid #e4e8f0; background: #f7f8fb; font-size: 0.95em; vertical-align: top;\"\u003eMolecular Formula\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 16px; color: #333; border-bottom: 1px solid #e4e8f0;\"\u003eC₅H₆N₂O₃\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 9px 16px; font-weight: 600; color: #002147; width: 200px; border-bottom: 1px solid #e4e8f0; background: #f7f8fb; font-size: 0.95em; vertical-align: top;\"\u003eMolecular Weight\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 16px; color: #333; border-bottom: 1px solid #e4e8f0;\"\u003e142.11 g\/mol\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 9px 16px; font-weight: 600; color: #002147; width: 200px; border-bottom: 1px solid #e4e8f0; background: #f7f8fb; font-size: 0.95em; vertical-align: top;\"\u003eMelting Point\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 16px; color: #333; border-bottom: 1px solid #e4e8f0;\"\u003e130–132 °C (lit.)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 9px 16px; font-weight: 600; color: #002147; width: 200px; border-bottom: 1px solid #e4e8f0; background: #f7f8fb; font-size: 0.95em; vertical-align: top;\"\u003eSolubility\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 16px; color: #333; border-bottom: 1px solid #e4e8f0;\"\u003eSoluble in DMF, NMP, acetonitrile, DCM, and water; partially soluble in toluene\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 9px 16px; font-weight: 600; color: #002147; width: 200px; border-bottom: 1px solid #e4e8f0; background: #f7f8fb; font-size: 0.95em; vertical-align: top;\"\u003ePurity\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 16px; color: #333; border-bottom: 1px solid #e4e8f0;\"\u003e≥95%\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 9px 16px; font-weight: 600; color: #002147; width: 200px; border-bottom: 1px solid #e4e8f0; background: #f7f8fb; font-size: 0.95em; vertical-align: top;\"\u003ePhysical Form\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 16px; color: #333; border-bottom: 1px solid #e4e8f0;\"\u003eWhite to off-white crystalline powder\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 9px 16px; font-weight: 600; color: #002147; width: 200px; border-bottom: 1px solid #e4e8f0; background: #f7f8fb; font-size: 0.95em; vertical-align: top;\"\u003eHS Code\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 16px; color: #333; border-bottom: 1px solid #e4e8f0;\"\u003e2928.00\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 9px 16px; font-weight: 600; color: #002147; width: 200px; border-bottom: 1px solid #e4e8f0; background: #f7f8fb; font-size: 0.95em; vertical-align: top;\"\u003eShelf Life\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 16px; color: #333; border-bottom: 1px solid #e4e8f0;\"\u003eRetest period: 36 months from date of manufacture\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 9px 16px; font-weight: 600; color: #002147; width: 200px; border-bottom: 1px solid #e4e8f0; background: #f7f8fb; font-size: 0.95em; vertical-align: top;\"\u003eStorage Conditions\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 16px; color: #333; border-bottom: 1px solid #e4e8f0;\"\u003eStore refrigerated (2–8 °C) in a tightly sealed container\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"margin-bottom: 28px;\"\u003e\n\u003cdiv style=\"background: #002147; padding: 10px 20px; margin-bottom: 0;\"\u003e\n\u003ch3 style=\"margin: 0; font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 0.70em; font-weight: bold; letter-spacing: 0.12em; text-transform: uppercase; color: #fff;\"\u003eProduct Description \u0026amp; Scientific Applications\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"padding: 16px 20px; border: 1px solid #e4e8f0; border-top: none; font-family: Georgia, 'Times New Roman', serif; font-size: 0.95em; line-height: 1.65; color: #333;\"\u003e\n\u003cp\u003e\u003cstrong\u003eOxyma\u003c\/strong\u003e (Oxyma Pure; ethyl (2Z)-2-cyano-2-(hydroxyimino)acetate; ethyl cyanoglyoxylate-2-oxime; ethyl isonitrosocyanoacetate) is the oxime of ethyl cyanoacetate and a non-benzotriazole coupling additive introduced as an alternative to the benzotriazole additives HOBt and HOAt. As a markedly acidic oxime (pKa ≈ 4.6), it traps the O-acylisourea formed from a carboxylic acid and a carbodiimide as a less racemisation-prone Oxyma active ester, while its acidity tempers the basic conditions that drive racemisation, giving high coupling efficiency with strong epimerisation suppression. Oxyma is used across solution-phase, solid-phase, and microwave-assisted peptide synthesis, and unlike uronium reagents used in excess, it does not cap the resin or growing peptide under standard coupling conditions.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCommon Scientific Applications\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCoupling additive for carbodiimide-mediated synthesis:\u003c\/strong\u003e Used with diisopropylcarbodiimide (DIC), EDC·HCl, or DCC to suppress racemisation and improve yields in amide-bond formation, by diverting the carbodiimide-generated O-acylisourea into a less racemisation-prone Oxyma active ester. Beyond peptides, the same activation strategy is used in broader amide and ester bond formation.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eAutomated and microwave-assisted Fmoc-SPPS:\u003c\/strong\u003e The Oxyma\/DIC combination is widely used in place of HOBt\/DIC on modern automated and microwave-assisted Fmoc solid-phase peptide synthesisers, delivering fast couplings and high crude-peptide purity under matched microwave conditions.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDifficult and sterically hindered couplings:\u003c\/strong\u003e In demanding sequences requiring double coupling, Oxyma\/DIC is competitive with — and in reported cases superior to — uronium systems such as HATU\/sym-collidine, improving the proportion of the target peptide in the crude product.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003epH-modulatory suppression of base-driven side reactions:\u003c\/strong\u003e Oxyma is a low-pKa additive whose buffering capacity tempers the basic conditions that drive several SPPS side reactions. Included in the Fmoc-deprotection step, it suppresses base-catalysed aspartimide formation and the derived piperidide, and it reduces proline-based overcoupling during chain elongation. Because Oxyma is acidic, its use with highly acid-labile supports such as 2-chlorotrityl chloride (2-CTC) resin warrants attention to the risk of premature cleavage; the less acidic potassium salt (K-Oxyma) is an alternative where acidity must be minimised.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eBeyond carbodiimide chemistry:\u003c\/strong\u003e Oxyma's oxime is the active-ester component of standalone third-generation coupling reagents — the uronium-type COMU and the PyOx family of phosphonium salts — and free Oxyma is also used as an additive with fluoroformamidinium reagents such as TFFH.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eGreener-solvent SPPS workflows:\u003c\/strong\u003e Oxyma's high solubility in a broad range of peptide-synthesis solvents supports its use in studies evaluating greener alternatives to DMF for solid-phase peptide synthesis, where solvent polarity, resin swelling, and reagent compatibility are matched to the sequence and resin.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eFurther Reading\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eFor guidance on selecting between carbodiimides, aminium\/uronium salts, phosphonium salts, and other reagent classes for amide and peptide bond formation, see NorrChemica's Lab Journal guide: \u003ca href=\"https:\/\/www.norrchemica.com\/blogs\/lab-journal\/choosing-a-coupling-reagent-for-amide-and-peptide-bond-formation\"\u003eChoosing a Coupling Reagent for Amide and Peptide Bond Formation\u003c\/a\u003e.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"margin-bottom: 28px;\"\u003e\n\u003cdiv style=\"background: #002147; padding: 10px 20px; margin-bottom: 0;\"\u003e\n\u003ch3 style=\"margin: 0; font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 0.70em; font-weight: bold; letter-spacing: 0.12em; text-transform: uppercase; color: #fff;\"\u003eShipping Destinations\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"border: 1px solid #e4e8f0; border-top: none; padding: 12px 16px; font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 0.95em;\"\u003e\n\u003cul style=\"margin: 0; padding: 0; list-style: none;\"\u003e\n\u003cli style=\"padding: 5px 0; border-bottom: 1px solid #f0f0f0;\"\u003e\n\u003cspan style=\"display: inline-block; width: 7px; height: 7px; background: #002147; border-radius: 50%; margin-right: 10px; vertical-align: middle;\"\u003e\u003c\/span\u003eEU \u0026amp; UK: Priority delivery, 2–5 business days.\u003c\/li\u003e\n\u003cli style=\"padding: 5px 0; border-bottom: 1px solid #f0f0f0;\"\u003e\n\u003cspan style=\"display: inline-block; width: 7px; height: 7px; background: #002147; border-radius: 50%; margin-right: 10px; vertical-align: middle;\"\u003e\u003c\/span\u003eUnited States (DDP): 3–7 business days, duties and taxes prepaid.\u003c\/li\u003e\n\u003cli style=\"padding: 5px 0; border-bottom: 1px solid #f0f0f0;\"\u003e\n\u003cspan style=\"display: inline-block; width: 7px; height: 7px; background: #002147; border-radius: 50%; margin-right: 10px; vertical-align: middle;\"\u003e\u003c\/span\u003eEFTA Countries (DDP): 3–7 business days, duties and taxes prepaid.\u003c\/li\u003e\n\u003cli style=\"padding: 5px 0; border-bottom: 1px solid #f0f0f0;\"\u003e\n\u003cspan style=\"display: inline-block; width: 7px; height: 7px; background: #002147; border-radius: 50%; margin-right: 10px; vertical-align: middle;\"\u003e\u003c\/span\u003eWorldwide: 7–14 business days, selected locations.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e","brand":"NorrChemica™","offers":[{"title":"5.0 g","offer_id":53484552094033,"sku":"NOR-3849216-5g","price":21.9,"currency_code":"EUR","in_stock":true},{"title":"10 g","offer_id":53484552126801,"sku":"NOR-3849216-10g","price":24.9,"currency_code":"EUR","in_stock":true},{"title":"25 g","offer_id":53484552159569,"sku":"NOR-3849216-25g","price":29.9,"currency_code":"EUR","in_stock":true},{"title":"50 g","offer_id":53484552192337,"sku":"NOR-3849216-50g","price":42.9,"currency_code":"EUR","in_stock":true},{"title":"100 g","offer_id":53484552225105,"sku":"NOR-3849216-100g","price":59.9,"currency_code":"EUR","in_stock":true},{"title":"250 g","offer_id":53484552257873,"sku":"NOR-3849216-250g","price":119.0,"currency_code":"EUR","in_stock":true},{"title":"500 g","offer_id":53484552290641,"sku":"NOR-3849216-500g","price":179.0,"currency_code":"EUR","in_stock":true},{"title":"1000 g","offer_id":53484552323409,"sku":"NOR-3849216-1000g","price":289.0,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0954\/6357\/1793\/files\/NorrChemica_Oxyma.png?v=1782683428","url":"https:\/\/www.norrchemica.com\/products\/oxyma-pure-cas-3849-21-6","provider":"NorrChemica","version":"1.0","type":"link"}