Studies on the Synthesis of 5-Trifluoromethylpiperonal

Trifluoromethylpiperonal was obtained by iodination, demethylation, methylene etherification and trifluoro- methyl reaction of vanillin in a satisfied yield. The chemical structure of the product was identified by 1 H NMR, 13 C NMR, 19 F NMR and HRMS. The optimal reaction conditions were investigated, including trifluoromethylation reagents, solvents, cata- lyst amounts, reaction temperature and reaction time. Meanwhile, three hydroxy substituted derivatives of 3,4-dihydroxy- 5-iodo-benzaldehyde were acquired by trifluoromethylation reaction with this method. Keywords 5-trifluoromethylpiperonal; trifluoromethylation reaction; synthesis