DIAPHRAGM-FREE ELECTROSYNTHESIS OF SUBSTITUTED PYRIDO[1,2-a]BENZIMIDAZOLES Russian patent published in 2015 - IPC C07D471/04 

FIELD: chemistry.

SUBSTANCE: invention relates to field of organic chemistry, namely to method of obtaining 7-R-pyrido[1,2-a]benzimidazoles of general formula, , where a) R=CF₃, R'=H; b) R=CN, R'=H; c) R=COOH, R'=H; d) R=COOCH₃, R'=H; e) R=COOC₂H₅, R'=H; f) R=COOPh, R'=H; g) R=CF₃, R'=CH₃; h) R=CN, R'=CH₃, which consists in the fact that reduction of N-(2-nitro-4-R-phenyl)-3,5-R'-pyridinium chlorides is carried out in mixture of alcohol and 4% hydrochloric acid, taken in ratio 1:1, by means of electric current in electrolyser without diaphragm in galvanostatic mode at temperature 40°C on lead cathode, with passing charge in 4 F for 0.5 h, current power 0.4 A through electrolytic cell, with application of platinum anode, target products are extracted by filtration of precipitated sediment after processing reaction mixture with ammonium hydroxide.

EFFECT: method of obtaining derivatives of pyrido[1,2-a]benzimidazoles, which can be applied as semi-products for synthesis of biologically active substances, demonstrating antioxidant activity, which finds application in field of optoelectronics, for example non-linear optics, has been elaborated.

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