Methanesulfonic Acid, 1,1,1‐Trifluoro‐, Nitro Ester

<jats:p> <jats:chem-struct-wrap> <jats:chem-struct> <jats:graphic xmlns:xlink="http://www.w3.org/1999/xlink" position="anchor" xlink:href="urn:x-wiley:9780470842898:media:rn02441:nrn02441sf.001"> <jats:alt-text>image</jats:alt-text> </jats:graphic> </jats:chem-struct> </jats:chem-struct-wrap> <jats:table-wrap position="anchor"> <jats:table frame="hsides"> <jats:col/> <jats:col/> <jats:col/> <jats:col/> <jats:tbody> <jats:tr> <jats:td> <jats:italic>[42262‐35‐1]</jats:italic> </jats:td> <jats:td> CF <jats:sub>3</jats:sub> NO <jats:sub>5</jats:sub> S </jats:td> <jats:td>Methanesulfonic acid, 1,1,1‐trifluoro‐, nitro ester</jats:td> <jats:td>(MW 195.07)</jats:td> </jats:tr> </jats:tbody> </jats:table> </jats:table-wrap> </jats:p> <jats:p> InChI =  <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="inchi" xlink:href="InChI=1S/CF3NO5S/c2-1(3,4)11(8,9)10-5(6)7">1S/CF3NO5S/c2‐1(3,4)11(8,9)10‐5(6)7</jats:ext-link> </jats:p> <jats:p> InChIKey =  <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="inchi" xlink:href="InChIKey=XTQCVIMYMUTLFT-UHFFFAOYSA-N">XTQCVIMYMUTLFT‐UHFFFAOYSA‐N</jats:ext-link> </jats:p> <jats:p> (reagent for electrophilic nitration, NO <jats:sub>2</jats:sub> transfers to nucleophiles) <jats:list list-type="simple"> <jats:list-item> <jats:p> <jats:italic>Alternative Names:</jats:italic> nitronium trifluoromethanesulfonate, triflyl nitrate, nitronium triflate, NO <jats:sub>2</jats:sub> OTf. </jats:p> </jats:list-item> <jats:list-item> <jats:p> <jats:italic>Physical Data:</jats:italic> mp 208–210 °C. <jats:sup> <jats:bold>1</jats:bold> </jats:sup> </jats:p> </jats:list-item> <jats:list-item> <jats:p> <jats:italic>Form Supplied in:</jats:italic> not commercially available, white solid. </jats:p> </jats:list-item> <jats:list-item> <jats:p> <jats:italic>Solubility:</jats:italic> limited solubility in non‐protonic solvents. </jats:p> </jats:list-item> <jats:list-item> <jats:p> <jats:italic>Analysis of Reagent Purity:</jats:italic> X‐ray crystallographic analysis, IR, Raman spectra, <jats:sup>13</jats:sup> C NMR, <jats:sup>19</jats:sup> F NMR. <jats:sup> <jats:bold>2–4</jats:bold> </jats:sup> </jats:p> </jats:list-item> <jats:list-item> <jats:p> <jats:italic>Preparative Method:</jats:italic> the original procedure by Coon <jats:sup> <jats:bold>2</jats:bold> </jats:sup> <jats:bold>Method A</jats:bold> . – Under an atmosphere of N <jats:sub>2</jats:sub> , a 6.00 g sample (40 mmol) of trifluoromethanesulfonic acid was placed in a 50 mL flask equipped with a mechanical stirrer, N <jats:sub>2</jats:sub> inlet tube, and dropping funnel. To this stirred liquid was added dropwise 1.26 g (20 mmol) of anhydrous nitric acid. As the nitric acid was added, a white, crystalline solid was continually formed. The resulting solid was allowed to stir for 1 h to ensure complete mixing and reaction. The product was shown to contain approximately the original weights of starting material by elemental analysis. <jats:bold>Method B</jats:bold> . – Under an atmosphere of N <jats:sub>2</jats:sub> , 6.00 g (40 mmol) of trifluoromethanesulfonic acid was dissolved in 100 mL of CH <jats:sub>2</jats:sub> Cl <jats:sub>2</jats:sub> in a 200 mL flask equipped with a mechanical stirrer, N <jats:sub>2</jats:sub> inlet tube, thermometer, and addition funnel. To this solution was added dropwise 1.26 g (20 mmol) of anhydrous nitric acid at 25 °C; no exotherm was noted. The solution was stirred for 15 min and then filtered under N <jats:sub>2</jats:sub> to collect a white, crystalline solid. The solid, 6.67 g, was dried under vacuum over P <jats:sub>2</jats:sub> O <jats:sub>5</jats:sub> and NaOH. </jats:p> </jats:list-item> <jats:list-item> <jats:p> Modified preparation by Averina, <jats:sup> <jats:bold>3</jats:bold> </jats:sup> <jats:bold>Method C</jats:bold> . – In a 20 mL glass vessel anhydrous HNO <jats:sub>3</jats:sub> (0.10 mol, 6.301 g) was added to CF <jats:sub>3</jats:sub> SO <jats:sub>3</jats:sub> H (0.05 mol, 7.504 g) and the mixture was placed in a vacuum desiccator with P <jats:sub>2</jats:sub> O <jats:sub>5</jats:sub> (20 g). The desiccator was evacuated and left for 2 weeks. The evacuation procedure was repeated twice a week. A white solid formed after 3–5 days and the liquid phase disappeared completely after two weeks to give NO <jats:sub>2</jats:sub> OTf (9.66 g). For most applied cases, NO <jats:sub>2</jats:sub> OTf could be prepared and used in situ from N <jats:sub>2</jats:sub> O <jats:sub>5</jats:sub> , NO <jats:sub>2</jats:sub> Cl or HNO <jats:sub>3</jats:sub> , and triflic acid or triflic anhydride. </jats:p> </jats:list-item> <jats:list-item> <jats:p> <jats:italic>Handling, Storage, and Precautions:</jats:italic> compound absorbs atmospheric water easily and irreversibly to form a mixture of nitric and triflic acids. Store in a dry bag under inert atmosphere. <jats:sup> <jats:bold>4</jats:bold> </jats:sup> </jats:p> </jats:list-item> </jats:list> </jats:p>