Facile microwave-assisted preparation of an ester-based cationic gemini surfactant for the improved micellar synthesis of aminocyanopyridines

Abstract

In this work, a diester cationic gemini surfactant (DCGS) was prepared from the reaction of N,N-dimethyldodecylamine with the microwave (MW)-assisted synthesized spacer ethane-1,2-diyl bis(2-chloroacetate) (EDBC) by the three-component reaction of ethylene glycol with chloroacetic acid (2 equiv.) under MW-irradiation. The structure of the spacer EDBC and surfactant DCGS were evaluated by 1H NMR, FT-IR, melting point, surface tension (γ), pendant drop, and critical micelle concentration (CMC) analysis and also cleavability test for DCGS. The γ and CMC for DCGS were 36.8 (∼50% γ H2O) and 1.62 × 10−5 mol L−1 and lower than simple GSs. The catalytic performance of DCGS was evaluated in the synthesis of aminocyanopyridines by the four-component reaction of acetophenone, malononitrile, (NH4)2CO3, and aldehydes in water. Thermal stability, easy separation and highest ever reported turnover number (TON) and turnover frequency (TOF) for synthesis of products are advantages of DCCGS.