p-Toluenesulfonyl Azide

[941-55-9] C7H7N3O2S (MW 197.24) InChI = 1S/C7H7N3O2S/c1-6-2-4-7(5-3-6)13(11,12)10-9-8/h2-5H,1H3 InChIKey = NDLIRBZKZSDGSO-UHFFFAOYSA-N (introduction of azide and diazo groups into organic compounds;2 serves as a source of nitrene and 1,3-azide dipoles for [3 + 2] cycloadditions;3 used for the synthesis of N-tosylphosphinimines,4 -sulfimines, and -sulfoximines5) Alternate Names: tosyl azide. Physical Data: mp 21–22 °C; bp 110–115 °C/0.001 mmHg;6 d25 1.286 g cm−3; 1.55010. Solubility: sol chloroform, diethyl ether, acetone. Form Supplied in: oily colorless liquid. Analysis of Reagent Purity: IR (neat) ν = 2130 (strong, NNN), 1380 and 1180 (strong, SO2) cm−1; 1H NMR (CDCl3) δ = 2.47 (s, CH3), 7.40 (d, J = 8 Hz, m-SO2C6H4), 7.84 (d, J = 8 Hz, o-SO2C6H4).7 Preparative Methods: the simplest synthetic method for tosyl azide is the reaction of p‐Toluenesulfonyl Chloride with Sodium Azide. Tosyl azide prepared in ethanol may contain 7–20% of ethyl p-toluenesulfonate;8 the formation of this byproduct can be avoided by working in aqueous acetone instead of ethanol.9, 10 The 1H NMR spectrum of tosyl azide prepared (99% yield) according to Curphey exhibits signals for traces of dichloromethane (<1%);10 the compound is pure by TLC, while HPLC reveals traces (>1.5%) of an impurity. Polymer-bound tosyl chloride can be transformed to polymer-bound tosyl azide.11 A polymer-bound phase-transfer catalyst may also be employed (94% yield).12 Further methods for the preparation of tosyl azide are the oxidation of p‐Toluenesulfonylhydrazide by Iron(III) Nitrate–K10 Montmorillonite Clay (83% yield),13 by Nitrogen Dioxide in CCl4 (95% yield),14 or by Nitrosonium Tetrafluoroborate (85% yield).15 Handling, Storage, and Precautions: crystallizes to a white solid at −20 °C and can be stored indefinitely at this temperature. Particular care is required for all reactions in which tosyl azide is heated at or above 100 °C. The initial temperature of the explosive decomposition is about 120 °C.16 Severe explosions during the attempted distillation of tosyl azide have been reported.6, 17 Polymer-bound tosyl azide can be stored indefinitely at room temperature and, in contrast to tosyl azide itself, is not sensitive to mechanical shock. Use in a fume hood.