An I 2011
First stage report
In the first stage was synthesized, according to the literature, benzimidazole through the condensation of the o-phenylen diamine with formic acid.In order to obtain the N-alkylation of the acidic nitrogen of imidazole derivatives (imidazole and benzimidazole) we used a Michael addition to acrylic acid derivatives (methyl or ethyl acrylate, acrylonitryl and acrylamide).
The new imidazol derivatives N1-alkylated were obtained with very good yields (over 90%). The mainly disadvantage of this reactions is the long reaction time (30-40 hours when the reaction solvent is acetonitrile). We have reduced the reaction time at 20-30 hours by changing the reaction solvent to toluene. Also in order to reduce the reaction time we used an unconventional synthetic method – under ultrasound irradiation. Ultrasound irradiation induces a remarkable acceleration for reactions, the reaction times decreases dramatically, from 20-30 hours to 2-3 hours. Also, under ultrasound irradiation the yields are higher by 3–5%.
A new, efficient and general method for the N1-alkylation of the imidazole derivatives using ultrasound irradiation was elaborated. Under ultrasound the reaction time decreases substantially, the yields are high and the reaction conditions are mild.
The structure of the compounds was proven by elemental (C, H, N) and spectral analysis. The following spectroscopic methods were used: IR, MS, 1H NMR, 13C NMR, 15N NMR and two-dimensional experiments 2D-COSY, 2D-HETCOR (HMQC), long range 2D-HETCOR (HMBC). All the elemental and spectral data are in accordance with the proposed structure.
We created also the web page of the project. Here will be published the final activity reports of the project stages.
It follows from the above that all of the objectives set for this step were carried out at 100%.