A study on the mechanism of reductive alkylation for preparing 3-(beta-hydroxy-ethyl-sulfonyl) N-ethyl aniline with HPLC/MS]
液相色谱/质谱联机研究还原烷基化合成3-(β-羟乙基砜基)N-乙基苯胺的反应历程

Hydrogenating 3-(beta-hydroxy-ethyl-sulfonyl)-aniline and acetaldehyde in the presence of Raney Nickel as a catalyst, 3-(beta-hydroxy-ethyl-sulfonyl)-N-ethyl-aniline was obtained with 98% conversion and 95% monoalkylation selectivity under optimum conditions. By using high performance liquid chromatography/mass selective detection technique to characterize the structures of the products, the mechanism of reductive alkylation is proposed. From the intermediates determined, it is shown that the reaction mechanism would go via an unstable N-alpha-hydroxyethylaniline derivative and Schiff base stage. After hydrogenation of Schiff base, finally the product 3-(beta-hydroxyethyl-sulfonyl)-N-ethyl aniline was formed.