| Synthesis of imines, widely spread in the nature and of high importance for many industries, often require complex procedures, long reaction times, use of large quantities of organic solvents, and acid catalysts in the liquid phase. We have developed a new process for the synthesis of imines without the use of any carbonyl compound, utilizing a safe and environmentally friendly K-10 montmorillonite solid acid catalyst along with Microwave-Assisted Organic Synthesis (MAOS). The catalyst was the medium for the reaction thus no additional organic solvent was used. As an additional advantage the initial oxidation of amines occurred in a catalytic manner using air as oxidant. The yields we obtained varied between 78 and 98 % in most of the cases.;The newly developed method involves the use of only different substituted benzylamines, benzylamine itself, and amines, consisting of aniline, substituted anilines, and some aliphatic amines as starting materials. No additional reagents, oxidizing agents were necessary.;The synthesis method described in this work provides significant improvements over the currently available methods for the synthesis of imines. It is simple, efficient, and green. The safety to personnel and environment is highly improved, by replacing hazardous reagents such as liquid acids with a safe and recyclable K-10 solid acid and conducting the reactions solvent-free avoiding fire-hazard during heating. Conventional heating is replaced by microwave heating, due to the more efficient internal heating energy is saved. Eliminating the need of the preliminary preparation of a carbonyl compounds is an inherent advantage on its own. |
