{"product_id":"pyoxim-cas-153433-21-7","title":"PyOxim | CAS 153433-21-7 | ≥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;\"\u003e153433-21-7\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;\"\u003e663-448-1\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;\"\u003eMFCD18643381\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(=N\/O[P+](N1CCCC1)(N2CCCC2)N3CCCC3)\/C#N.F[P-](F)(F)(F)(F)F\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\/C17H29N5O3P.F6P\/c1-2-24-17(23)16(15-18)19-25-26(20-9-3-4-10-20,21-11-5-6-12-21)22-13-7-8-14-22;1-7(2,3,4,5)6\/h2-14H2,1H3;\/q+1;-1\/b19-16+;\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;\"\u003eRDWDVLFMPFUBDV-PXMDEAMVSA-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;\"\u003e46910530\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;\"\u003eC₁₇H₂₉F₆N₅O₃P₂\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;\"\u003e527.38 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;\"\u003e172 °C\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, DCM, NMP; insoluble in water, diethyl ether\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 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;\"\u003e2926.90\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 under inert atmosphere, protected from moisture\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\u003ePyOxim\u003c\/strong\u003e ([ethyl cyano(hydroxyimino)acetato-O²]tri-1-pyrrolidinylphosphonium hexafluorophosphate) is a phosphonium-type peptide coupling reagent that pairs the Oxyma leaving group (ethyl 2-cyano-2-(hydroxyimino)acetate) with a tripyrrolidinophosphonium cation and a hexafluorophosphate counterion. It belongs to the non-benzotriazole, Oxyma-based family of coupling reagents. In the presence of a tertiary-amine base such as DIPEA it activates a carboxylic acid as the corresponding Oxyma-based active ester, which then acylates the amine to form the amide bond. Its coupling efficiency is comparable to COMU; in demanding model couplings it outperformed the benzotriazole-based phosphonium reagents PyBOP, PyAOP and PyClock, with low racemisation. Because it carries a phosphonium rather than an aminium centre, PyOxim cannot guanidinylate the free amine of the growing chain — a chain-terminating side reaction associated with aminium reagents such as HATU and HBTU. It dissolves readily in DMF and is used in solid- and solution-phase peptide synthesis.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCommon Scientific Applications\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eSolid- and solution-phase peptide synthesis:\u003c\/strong\u003e PyOxim is a phosphonium coupling reagent for solid- and solution-phase peptide-bond formation, activating protected amino acids with high coupling efficiency and low racemisation across short to demanding sequences.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCyclic peptide synthesis and fragment condensation:\u003c\/strong\u003e Because it forms no guanidinated by-products, PyOxim preserves the free N-terminus during convergent fragment (segment) condensation and peptide cyclisation. In cyclisation models it delivered a higher proportion of cyclic product than other established phosphonium salts, supporting its use in cyclic-peptide work.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eSterically hindered and configurationally labile couplings:\u003c\/strong\u003e The Oxyma-based activation couples demanding residues — including consecutive α-aminoisobutyric acid (Aib) and other hindered amino acids — with low epimerisation, in model couplings where benzotriazole-based phosphonium reagents give lower conversion.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eStable reagent solutions:\u003c\/strong\u003e PyOxim combines high solubility in DMF with good stability in solution, so activator solutions prepared in advance remain usable longer than those of less stable reagents — useful wherever reagent solutions stand before use, including automated multi-cycle synthesis.\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":"1.0 g","offer_id":53493548122449,"sku":"NOR-153433217-1g","price":24.0,"currency_code":"EUR","in_stock":true},{"title":"5.0 g","offer_id":53493548155217,"sku":"NOR-153433217-5g","price":40.0,"currency_code":"EUR","in_stock":true},{"title":"10 g","offer_id":53493548187985,"sku":"NOR-153433217-10g","price":65.0,"currency_code":"EUR","in_stock":true},{"title":"25 g","offer_id":53493548220753,"sku":"NOR-153433217-25g","price":105.0,"currency_code":"EUR","in_stock":true},{"title":"50 g","offer_id":53493548253521,"sku":"NOR-153433217-50g","price":174.0,"currency_code":"EUR","in_stock":true},{"title":"100 g","offer_id":53493548286289,"sku":"NOR-153433217-100g","price":298.0,"currency_code":"EUR","in_stock":true},{"title":"250 g","offer_id":53493548319057,"sku":"NOR-153433217-250g","price":598.0,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0954\/6357\/1793\/files\/NorrChemica_PyOxim.png?v=1782683428","url":"https:\/\/www.norrchemica.com\/products\/pyoxim-cas-153433-21-7","provider":"NorrChemica","version":"1.0","type":"link"}