METHOD OF OBTAINING 7-R-PYRIDO[1,2-a]BENZIMIDAZOLES Russian patent published in 2014 - IPC C07D471/04 

FIELD: chemistry.

SUBSTANCE: invention relates to a method of obtaining 7-R-pyrido[1,2-a]benzimidazoles of the general formula where R=a) CF₃, b) CN, c) COOH, d) C(O)NH₂, e) COOCH₃, f) COOC₂H₅, consisting in the following: reduction of chlorides of N-(2-nitro-4-R-phenyl)pyridinium is carried out in a mixture of alcohol and 4% hydrochloric acid, taken at a ratio 1:1, by means of electric current in a diaphragm cell in a galvanostatic mode at a temperature of 40-45°C on a lead cathode, with passing through an electrolytic cell 4 F charge for 0.5 h, with current intensity 0.6 A, as an anolyte used is 15% of sulphuric acid, and as an anode - platinum; target products are separated by filtration of a precipitated sediment after processing of a reaction mixture with ammonium hydroxide.

EFFECT: novel reagent-free method, making it possible to reduce synthesis cost and simplify the process of the target product separation, is elaborated.

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