Abstract
In the current paper, we report nanosized zeolite beta to be a robust and potent catalyst for tert-butylation of aniline. Nanocrystals of beta zeolite having spherical morphology were prepared via a one-pot strategy that is based on vacuum-concentration coupled hydrothermal method. The catalyst could be used in the as-synthesized form, without any further modifications. In the presence of the as-prepared catalyst, liquid-phase tert-butylation of aniline using tert-butanol as alkylating agent proceeded successfully. Reaction parameters like duration of reaction, temperature, mole ratio of substrates and quantity of catalyst were optimized. Time-dependent data obtained was subjected to kinetic studies. Detailed studies on product selectivity were conducted. The catalyst could selectively direct the formation of C-C bonds and no N-alkylated products were detected. It also demonstrated good selectivity towards mono-substitution. The catalyst could be recovered by a simple work-up plan and could then be re-used. No appreciable loss in activity was detected in consecutive runs. Thus, the nanosized beta mediated route to introduce tert-butyl group on aniline ring can be an environment-friendly alternative to the use of homogeneous catalysts.