Mercury(II) p‐toluenesulfonamidate

[55538-99-3] C14H16HgN2O4S2 (MW 540.59) InChI = 1S/2C7H8NO2S.Hg/c2*1-6-2-4-7(5-3-6)11(8,9)10;/h2*2-5H,1H3,(H-,8,9,10);/q2*-1;+2 InChIKey = QYNLZRPCCATAIJ-UHFFFAOYSA-N (regioselective hydration of terminal alkynes, hydration of internal alkynes) Alternate name: mercuric p-toluenesulfonamidate. Physical Data: m.p.: 249.8–250.7 °C. (Determined in a closed capillary tube, previously purged with Ar). Solubility: MeOH: 0.34 mg/mL; EtOH: 0.10 mg/mL; ACN: 1.12 mg/mL; MeOH:H2O (85:15):0.59 mg/mL; EtOH:H2O (85:15):0.30 mg/mL; ACN:H2O (85:15): 0.84 mg/mL. Insoluble in water and alkanes. Spectroscopic data: IR(KBr): 3307, 3036–3024, 2978, 1910–1652, 1276, 1139, 945, 812 cm−1. 1H-NMR (300 MHz, DMSO-d6) δ, ppm: 7.66 (d, J = 7 Hz, 2H), 7.34 (d, J = 7 Hz, 2H), 2.35 (s, 3H). 13C-NMR (100 MHz, DMSO-d6) δ, ppm: 20.7, 125.5, 129.0, 129.1, 141.67. Form Supplied in: not commercially available. Preparation Method: mercury(II) p-toluenesulfonamidate can be prepared from mercury(II) oxide and p-toluenesulfonamide, according to the following procedure p-Toluenesulfonamide (29.66 g, 173.2 mmol) and HgO (18.28 g, 83.1 mmol) are ground together in a mortar to a very fine, homogeneous powder. The mixture is placed in a crucible and warmed up to 200 °C in an oven for 1.5 h. The mixture is stirred with a glass rod every 15 min. Once the orange color of HgO disappears the reaction is complete. The crucible is cooled down to room temperature and the solid transferred to a round-bottomed flask fitted with a reflux condenser. EtOH (150 mL) is added and the solution is refluxed for 30 min to dissolve excess unreacted p-toluenesulfonamide, then, the mixture is filtered hot. After lixiviation the resulting residue is dried in a desiccator containing phosphorus pentoxide for 1 d to obtain pure product as a white solid (36.12 g, 89%). Purification: if prepared according to the described procedure, further purification is not necessary. Handling, Storage, and Precautions: The reagent is stable for years under normal operating conditions. It is highly toxic and is absorbed through the skin. Ingestion and exposure of eyes and mucoses to all mercury compounds should be strictly avoided. The reagent releases toxic Hg fumes when heated to decomposition. Protect from light. Use in a fume hood and wear protective gloves when handling. Residue processing: Mercury(II) may be made inert in the form of HgS (see the following hydration protocol) and separated by filtration or centrifugation. The HgS residues should be stored in appropriate containers for heavy metals and send to specialized companies for adequate disposal. In any case, this reagent is used in tiny catalytic amounts (0.01–0.2 molar ratios), so the amount of residual mercury generated in the hydration reactions is very small. In some cases and for some type of substrates, this reagent can be recovered, recycled, and reused.