{"product_id":"tbtu-cas-125700-67-6","title":"TBTU | CAS 125700-67-6 | ≥98%","description":"\u003cp\u003e \u003c\/p\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;\"\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;\"\u003e125700-67-6\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;\"\u003e423-040-4\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;\"\u003eMFCD00077413\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;\"\u003e[B-](F)(F)(F)F.CN(C)C(=[N+](C)C)ON1C2=CC=CC=C2N=N1\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\/C11H16N5O.BF4\/c1-14(2)11(15(3)4)17-16-10-8-6-5-7-9(10)12-13-16;2-1(3,4)5\/h5-8H,1-4H3;\/q+1;-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;\"\u003eInChIKey\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 16px; color: #333; border-bottom: 1px solid #e4e8f0; word-break: break-all;\"\u003eJKEKMBGUVUKMQB-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;\"\u003e2733207\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;\"\u003eC₁₁H₁₆BF₄N₅O\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;\"\u003e321.08 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;\"\u003e195–199 °C (dec.)\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, DMSO; 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≥98%\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 pale cream 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;\"\u003e2933.99\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;\"\u003eCountry of Origin\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 16px; color: #333; border-bottom: 1px solid #e4e8f0;\"\u003eFinland\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, protected from moisture and light\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\u003eTBTU (O-(benzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium tetrafluoroborate) is a benzotriazole-based uronium\/guanidinium coupling reagent for Fmoc and Boc peptide synthesis and general amide-bond formation. It activates carboxylic acids as benzotriazol-1-yl (OBt) active esters under mild, base-promoted conditions, giving high coupling yields with low racemisation.\u003c\/p\u003e\n\u003cdiv style=\"display: flex; justify-content: center; margin: 6px 0 14px 0;\"\u003e\n\u003cdiv style=\"display: flex; align-items: center;\"\u003e\u003csvg role=\"img\" style=\"max-width: 100%; height: auto;\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"250px\" height=\"150px\" viewbox=\"0 0 250 150\"\u003e\u003cpath class=\"bond-0 atom-0 atom-1\" d=\"M 59.4,97.8 L 74.3,91.7\" style=\"fill:none;fill-rule:evenodd;stroke:#000000;stroke-width:1.0px;stroke-linecap:butt;stroke-linejoin:miter;stroke-opacity:1\"\u003e\u003c\/path\u003e\u003cpath class=\"bond-1 atom-1 atom-2\" d=\"M 79.2,84.8 L 81.2,69.7\" style=\"fill:none;fill-rule:evenodd;stroke:#000000;stroke-width:1.0px;stroke-linecap:butt;stroke-linejoin:miter;stroke-opacity:1\"\u003e\u003c\/path\u003e\u003cpath class=\"bond-2 atom-1 atom-3\" d=\"M 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fill=\"#000000\"\u003e\u003c\/path\u003e\u003c\/svg\u003e\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cp\u003e\u003cstrong\u003eFmoc and Boc Solid-Phase Peptide Synthesis\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eTBTU is one of the most widely used coupling reagents for both Fmoc- and Boc-based SPPS. In the activation step, TBTU reacts with the carboxylic acid of the incoming protected amino acid in the presence of a tertiary amine base (DIPEA or NMM) to generate a benzotriazolyl active ester intermediate, which undergoes rapid aminolysis with the resin-bound free amine to form the peptide bond. Like HBTU, TBTU exists as the guanidinium N-oxide (aminium) form in the solid state, and the two reagents behave essentially identically in coupling reactions — differing only in the counterion (BF₄⁻ for TBTU vs PF₆⁻ for HBTU).\u003c\/p\u003e\n\u003cp\u003eKnorr et al. (Tetrahedron Lett. 1989, 30, 1927) introduced TBTU as a highly efficient coupling reagent with low racemisation, and it has since become one of the standard reagents in both academic and industrial peptide synthesis. Hachmann and Lebl (Biopolymers 2006, 84, 340) included TBTU in a systematic comparative study of ten phosphonium and uronium coupling reagents, confirming its reliable performance across a range of peptide sequences.\u003c\/p\u003e\n\u003cdiv style=\"margin: 8px 0 18px 0;\"\u003e\n\u003cdiv style=\"display: flex; flex-wrap: wrap; align-items: center; justify-content: flex-start; gap: 2px;\"\u003e\n\u003cdiv style=\"display: flex; align-items: center;\"\u003e\u003csvg role=\"img\" style=\"max-width: 100%; height: auto;\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"120px\" height=\"95px\" viewbox=\"0 0 120 95\"\u003e\u003cpath class=\"bond-0 atom-0 atom-1\" d=\"M 21.2,77.4 L 54.8,58.1\" style=\"fill:none;fill-rule:evenodd;stroke:#000000;stroke-width:1.0px;stroke-linecap:butt;stroke-linejoin:miter;stroke-opacity:1\"\u003e\u003c\/path\u003e\u003cpath class=\"bond-1 atom-1 atom-2\" d=\"M 58.1,60.0 L 58.1,20.2\" 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81.7 75.9L 81.7 79.8L 86.5 79.8L 86.5 75.9L 87.7 75.9L 87.7 85.1L 86.5 85.1L 86.5 80.8L 81.7 80.8L 81.7 85.1L 80.5 85.1L 80.5 75.9\" fill=\"#000000\"\u003e\u003c\/path\u003e\u003cpath class=\"atom-4\" d=\"M 118.5 56.1L 116.3 52.3L 116.3 52.3L 114.8 52.3L 114.8 56.1L 113.6 56.1L 113.6 46.9L 116.3 46.9Q 117.9 46.9, 118.7 47.6Q 119.4 48.3, 119.4 49.6Q 119.4 50.6, 119.0 51.2Q 118.5 51.9, 117.6 52.1L 119.9 56.1L 118.5 56.1M 114.8 51.3L 116.3 51.3Q 117.2 51.3, 117.7 50.8Q 118.1 50.4, 118.1 49.6Q 118.1 48.8, 117.7 48.4Q 117.2 47.9, 116.3 47.9L 114.8 47.9L 114.8 51.3\" fill=\"#000000\"\u003e\u003c\/path\u003e\u003cpath class=\"atom-4\" d=\"\" fill=\"#000000\"\u003e\u003c\/path\u003e\u003cpath class=\"atom-4\" d=\"\" fill=\"#000000\"\u003e\u003c\/path\u003e\u003cpath class=\"atom-4\" d=\"\" fill=\"#000000\"\u003e\u003c\/path\u003e\u003c\/svg\u003e\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cp style=\"font-size: 12px; margin: 4px 0 0 0;\"\u003e\u003cem\u003eGeneral reaction: TBTU converts the carboxylic acid into a benzotriazol-1-yl (OBt) active ester, releasing tetramethylurea; the active ester is then aminolysed by the amine to give the amide.\u003c\/em\u003e\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cp\u003e\u003cstrong\u003eSolution-Phase Peptide Synthesis and Fragment Condensation\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eTBTU is equally effective in solution-phase peptide synthesis, where its high solubility in polar aprotic solvents — DMF, NMP, and DMSO — facilitates homogeneous reaction conditions. The BF₄⁻ counterion confers slightly higher solubility in some solvent systems compared to the PF₆⁻ salt (HBTU), which can be advantageous when working at high substrate concentrations or with poorly soluble peptide fragments.\u003c\/p\u003e\n\u003cp\u003eIn fragment condensation reactions, TBTU provides efficient coupling between large protected peptide segments with minimal epimerisation, although — like all uronium\/aminium reagents — it should not be used in large excess to avoid the guanidination side reaction that can cap free amino groups.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eSynthesis of 1,2,4-Oxadiazoles\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eBeyond peptide chemistry, TBTU has been employed as an activating agent for the synthesis of 1,2,4-oxadiazoles — five-membered heterocyclic ring systems with broad pharmacological relevance, including antimicrobial, anti-inflammatory, and anticancer activity. Poulain et al. (Tetrahedron Lett. 2001, 42, 1495) demonstrated that TBTU efficiently activates carboxylic acids for cyclodehydration with amidoximes, providing 1,2,4-oxadiazoles in good yields under mild conditions. This application exploits the same carboxylic acid activation mechanism used in peptide synthesis but redirects it towards heterocycle formation.\u003c\/p\u003e\n\u003cdiv style=\"margin: 8px 0 18px 0;\"\u003e\n\u003cdiv style=\"display: flex; flex-wrap: wrap; align-items: center; justify-content: flex-start; gap: 2px;\"\u003e\n\u003cdiv style=\"display: flex; align-items: center;\"\u003e\u003csvg role=\"img\" style=\"max-width: 100%; height: auto;\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"120px\" height=\"95px\" viewbox=\"0 0 120 95\"\u003e\u003cpath class=\"bond-0 atom-0 atom-1\" d=\"M 21.2,77.4 L 54.8,58.1\" style=\"fill:none;fill-rule:evenodd;stroke:#000000;stroke-width:1.0px;stroke-linecap:butt;stroke-linejoin:miter;stroke-opacity:1\"\u003e\u003c\/path\u003e\u003cpath class=\"bond-1 atom-1 atom-2\" d=\"M 58.1,60.0 L 58.1,20.2\" 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line-height: 1.3;\"\u003e\n\u003cdiv\u003eTBTU, base\u003c\/div\u003e\n\u003cdiv style=\"font-size: 30px; line-height: 1;\"\u003e⟶\u003c\/div\u003e\n\u003cdiv\u003evia OBt ester\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"display: flex; align-items: center;\"\u003e\u003csvg role=\"img\" style=\"max-width: 100%; height: auto;\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"240px\" height=\"130px\" viewbox=\"0 0 240 130\"\u003e\u003cpath class=\"bond-0 atom-0 atom-1\" d=\"M 30.1,84.6 L 55.5,62.6\" style=\"fill:none;fill-rule:evenodd;stroke:#000000;stroke-width:1.0px;stroke-linecap:butt;stroke-linejoin:miter;stroke-opacity:1\"\u003e\u003c\/path\u003e\u003cpath class=\"bond-1 atom-1 atom-2\" d=\"M 58.7,63.7 L 52.1,29.4\" style=\"fill:none;fill-rule:evenodd;stroke:#000000;stroke-width:1.0px;stroke-linecap:butt;stroke-linejoin:miter;stroke-opacity:1\"\u003e\u003c\/path\u003e\u003cpath class=\"bond-1 atom-1 atom-2\" d=\"M 52.9,64.9 L 46.3,30.5\" style=\"fill:none;fill-rule:evenodd;stroke:#000000;stroke-width:1.0px;stroke-linecap:butt;stroke-linejoin:miter;stroke-opacity:1\"\u003e\u003c\/path\u003e\u003cpath class=\"bond-2 atom-1 atom-3\" d=\"M 55.5,62.6 L 87.2,73.6\" style=\"fill:none;fill-rule:evenodd;stroke:#000000;stroke-width:1.0px;stroke-linecap:butt;stroke-linejoin:miter;stroke-opacity:1\"\u003e\u003c\/path\u003e\u003cpath class=\"bond-3 atom-3 atom-4\" d=\"M 98.3,70.8 L 117.8,53.9\" style=\"fill:none;fill-rule:evenodd;stroke:#000000;stroke-width:1.0px;stroke-linecap:butt;stroke-linejoin:miter;stroke-opacity:1\"\u003e\u003c\/path\u003e\u003cpath class=\"bond-4 atom-4 atom-5\" d=\"M 127.4,51.4 L 159.9,62.6\" style=\"fill:none;fill-rule:evenodd;stroke:#000000;stroke-width:1.0px;stroke-linecap:butt;stroke-linejoin:miter;stroke-opacity:1\"\u003e\u003c\/path\u003e\u003cpath class=\"bond-4 atom-4 atom-5\" d=\"M 125.5,57.0 L 154.7,67.1\" 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class=\"atom-7\" d=\"\" fill=\"#000000\"\u003e\u003c\/path\u003e\u003cpath class=\"atom-7\" d=\"\" fill=\"#000000\"\u003e\u003c\/path\u003e\u003c\/svg\u003e\u003c\/div\u003e\n\u003cdiv style=\"display: flex; align-items: center;\"\u003e\n\u003cdiv style=\"display: flex; flex-direction: column; align-items: center; justify-content: center; min-width: 120px; max-width: 180px; padding: 0 6px; text-align: center; font-size: 12px; line-height: 1.3;\"\u003e\n\u003cdiv\u003e– H₂O\u003c\/div\u003e\n\u003cdiv style=\"font-size: 30px; line-height: 1;\"\u003e⟶\u003c\/div\u003e\n\u003cdiv\u003ecyclodehydration, Δ\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"display: flex; align-items: center;\"\u003e\u003csvg role=\"img\" style=\"max-width: 100%; height: auto;\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"160px\" height=\"115px\" viewbox=\"0 0 160 115\"\u003e\u003cpath class=\"bond-0 atom-0 atom-1\" d=\"M 19.0,70.6 L 43.4,62.7\" 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48.5 34.1M 52.7 37.8Q 54.1 37.8, 54.9 36.9Q 55.7 36.0, 55.7 34.1Q 55.7 32.3, 54.9 31.4Q 54.1 30.5, 52.7 30.5Q 51.3 30.5, 50.6 31.4Q 49.8 32.3, 49.8 34.1Q 49.8 36.0, 50.6 36.9Q 51.3 37.8, 52.7 37.8\" fill=\"#000000\"\u003e\u003c\/path\u003e\u003c\/svg\u003e\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cp style=\"font-size: 12px; margin: 4px 0 0 0;\"\u003e\u003cem\u003eGeneral reaction: the TBTU-activated acid O-acylates the amidoxime; the O-acylamidoxime then cyclodehydrates to the 3,5-disubstituted 1,2,4-oxadiazole.\u003c\/em\u003e\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cp\u003e\u003cstrong\u003eSelective Esterification and Glycodendrimer Synthesis\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eTBTU enables controllably selective esterification of carboxylic acids with alcohols — a transformation that is typically difficult with standard coupling reagents due to the lower nucleophilicity of alcohols compared to amines. Twibanire and Grindley (Org. Lett. 2011, 13, 2988) demonstrated efficient and selective preparation of esters using TBTU, including the synthesis of acid-based T-antigen glycodendrimers — multivalent carbohydrate-presenting structures used in cancer immunology research. 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90.8 77.4Q 90.0 78.3, 90.0 80.1Q 90.0 82.0, 90.8 82.9Q 91.6 83.9, 93.0 83.9\" fill=\"#000000\"\u003e\u003c\/path\u003e\u003cpath class=\"atom-3\" d=\"M 98.6 75.6L 99.9 75.6L 99.9 79.5L 104.6 79.5L 104.6 75.6L 105.8 75.6L 105.8 84.8L 104.6 84.8L 104.6 80.5L 99.9 80.5L 99.9 84.8L 98.6 84.8L 98.6 75.6\" fill=\"#000000\"\u003e\u003c\/path\u003e\u003c\/svg\u003e\u003c\/div\u003e\n\u003cdiv style=\"display: flex; align-items: center;\"\u003e\n\u003cdiv style=\"display: flex; flex-direction: column; align-items: center; justify-content: center; min-width: 120px; max-width: 180px; padding: 0 6px; text-align: center; font-size: 12px; line-height: 1.3;\"\u003e\n\u003cdiv\u003eTBTU, base\u003c\/div\u003e\n\u003cdiv style=\"font-size: 30px; line-height: 1;\"\u003e⟶\u003c\/div\u003e\n\u003cdiv\u003e\u003cbr\u003e\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"display: flex; align-items: center;\"\u003e\u003csvg role=\"img\" style=\"max-width: 100%; height: auto;\" 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116.6 57.3L 115.1 57.3L 115.1 61.1L 113.9 61.1L 113.9 51.9L 116.6 51.9Q 118.2 51.9, 119.0 52.6Q 119.8 53.3, 119.8 54.6Q 119.8 55.6, 119.3 56.3Q 118.8 56.9, 117.9 57.2L 120.2 61.1L 118.9 61.1M 115.1 56.3L 116.6 56.3Q 117.5 56.3, 118.0 55.9Q 118.5 55.4, 118.5 54.6Q 118.5 53.8, 118.0 53.4Q 117.5 53.0, 116.6 53.0L 115.1 53.0L 115.1 56.3\" fill=\"#000000\"\u003e\u003c\/path\u003e\u003cpath class=\"atom-4\" d=\"\" fill=\"#000000\"\u003e\u003c\/path\u003e\u003cpath class=\"atom-4\" d=\"\" fill=\"#000000\"\u003e\u003c\/path\u003e\u003cpath class=\"atom-4\" d=\"\" fill=\"#000000\"\u003e\u003c\/path\u003e\u003c\/svg\u003e\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cp style=\"font-size: 12px; margin: 4px 0 0 0;\"\u003e\u003cem\u003eGeneral reaction: the same benzotriazol-1-yl active ester is intercepted by an alcohol instead of an amine, giving the ester.\u003c\/em\u003e\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cp\u003e\u003cstrong\u003eCost-Effective HBTU Alternative\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eTBTU is generally less expensive than HBTU due to the lower cost of the tetrafluoroborate counterion compared to hexafluorophosphate. For laboratories and manufacturing facilities where coupling reagent cost is a significant consideration — particularly in large-scale GMP peptide production requiring thousands of coupling cycles per campaign — TBTU offers an economically attractive alternative with no loss of coupling performance. The two reagents can be used interchangeably in virtually all protocols, and TBTU has been validated in the synthesis of numerous therapeutically active peptides including peptaibols, opioid analogues, and trehalose-based glycolipids.\u003c\/p\u003e\n\u003cp\u003eThe only practical distinction is that TBTU is classified as a flammable solid (H228) for transport, requiring appropriate packaging and shipping as dangerous goods — a consideration that may influence procurement logistics but does not affect synthetic performance.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eFurther Reading.\u003c\/strong\u003e For 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 only: 3–7 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\u003eClassified as dangerous goods — shipping restrictions apply outside the EU\/UK.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e","brand":"NorrChemica™","offers":[{"title":"5 g","offer_id":53486796276049,"sku":"NOR-125700676-5g","price":39.9,"currency_code":"EUR","in_stock":true},{"title":"10 g","offer_id":55109875827025,"sku":"NOR-125700676-10g","price":49.2,"currency_code":"EUR","in_stock":true},{"title":"25 g","offer_id":55109875859793,"sku":"NOR-125700676-25g","price":69.2,"currency_code":"EUR","in_stock":true},{"title":"50 g","offer_id":55109875892561,"sku":"NOR-125700676-50g","price":98.2,"currency_code":"EUR","in_stock":true},{"title":"100 g","offer_id":55109875925329,"sku":"NOR-125700676-100g","price":129.2,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0954\/6357\/1793\/files\/NorrChemica_TBTU.png?v=1782683467","url":"https:\/\/www.norrchemica.com\/products\/tbtu-cas-125700-67-6","provider":"NorrChemica","version":"1.0","type":"link"}