2,2‐Bis(trifluoromethyl)‐2‐hydroxyacetic Acid

[662-22-6] C4H2F6O3 (MW 212.05) InChI = 1S/C4H2F6O3/c5-3(6,7)2(13,1(11)12)4(8,9)10/h13H,(H,11,12) InChIKey = CMQUGOHGJUTDGZ-UHFFFAOYSA-N (reagent used for introducing OC(CF3) 2CO2 into a wide array of substituents) Physical Data: mp 82–85 °C; bp 153–156 °C. Solubility: soluble in MeCN, ether. Purification: by distillation. Preparative Methods: the reagent 2,2-bis(trifluoromethyl)-2-hydroxyacetic acid (BTHA) could be synthesized in 39% yield by heating perfluoroisobutylene oxide with silica gel in aqueous acetone for 12 h at 100 °C in a sealed tube (eq 1).1 (1) Alternatively, it can also be prepared by first reacting (CF3)2CO with HCN in the presence of piperidine to generate the cyanohydrin, (CF3)2C(OH)CN, followed by rigorous treatment with H2SO4 to deliver BTHA in 62% yield (eq 2).2 A similar procedure where KCN and hexafluoroacetone react in anhydrous THF and ethyl ether followed by refluxing with H2SO4 to give the reagent in 60% yield is also reported.3 (2)