Study On Synthesis Process Of3-tert-butyl-2,5-dihydroxybenzaldehyde

3-tert-Butyl-2,5-dihydroxybenzaldehyde was an important intermediate to synthesize some chiral Salen complexes. Chiral Salen complexes serve as asymmetric catalysts widely used in asymmetric epoxides reactions, enantioselective epoxides ring-opening reactions, asymmetric silylcyanation, selective hydrogenation reactions, hydrolytic kinetic resolution of racemic terminal epoxides and other areas.A process to synthesize3-ter/-butyl-2,5-dihydroxybenzaldehyde has been designed and optimized in this paper.3-tert-Butyl-2,5-dihydroxybenzaldehyde was prepared by protection of4-hydroxy group of2-tert-butylhydroquinone with benzyl chloride, catalytic formylation with paraformaldehyde and cleavage of benzyl group. Protection of4-hydroxy group by benzyl chloride was carried by potassium carbonate as a base, and potassium iodide as an initiator. Formylation by paraformaldehyde was catalyzed by tin tetrachloride and triethylamine as a deacid reagent. Cleavage of protecting group was worked in acetic acid/hydrochloric acid, and the total yield of above three steps was41.7%. The product was purified by ethyl acetate/methylene chloride, and the purity of3-tert-butyl-2,5-dihydroxy-benzaldehyde was98.5%. The intermediates and target compound was determined by1H-NMR.