Study On The Synthesis Of 2-Substituted Resorcinols

2-Substituted resorcinols are important intermediates for organic synthesis. In this paper, 2-isopropyl resorcinol was prepared from resorcinol by a three-steps way including di-t-butylation, isopropylation and de-t-butylation.The synthesis of 4,6-di-t-butyl resorcinol was studied with H2SO4 and acidic ion-exchanged resin as the catalysts, respectively. The yields (purity) of 4,6-di-t-butyl resorcinol prepared from resorcinol alkylated by t-butanol were 90.1%(93.96%), 85.8%(98.77%), the yields (purity) of 4,6-di-t-butyl resorcinol prepared from resorcinol alkylated by methyl-t-butyl ether were 62.2%(95.23%), 55.9% (92.66%), respectively. It was evaluated particularly that the factors influencing the yield and purity of 4,6-di-t-butyl resorcinol including the catalyst amount, reaction temperature, reaction time and t-butanol amount etc.The synthesis of 2-isopropyl-4,6-di-t-butyl resorcinol was studied with hexane and aqueous alkali as solvent, the yield (purity) of 2-isopropyl-4,6-di-t-butyl resorcinol was 65.5%(95.70%) with 2-bromic propane added by dropping. It was 66.5% in yield when 2-bromic propane was added directly in the presence of KI. The yield was 61.7% when the reaction was carried without organic solvent. The compound was characterized by 1H NMR. Several kinds of PTC catalysts and surface-active agents were chosen to study further the reaction.The synthesis of 2-isopropyl resorcinol was catalyzed by H2SO4 with nitrobenzene or dichlorictoluene as solvent. The yield (purity) of 2-isopropyl resorcinol was 81.0%(95.54%), 76.7%(96.14%), respectively. The compound was characterized by 1H NMR and element analysis. The purity of product was above 97.0% after recrystallization,Another three 2-substituted resorcinols were prepared by the similar routes including 2-ethyl resorcinol, 2-butyl resorcinol and 2-benzyl resorcinol with the yield (purity) of 98.8% (95.15%), 34.3%(97.07%), 64.1%(95.28%), respectively.