New methods of synthesis, structure and aminomethylation of 4-imino-2-(dicyanomethylene)-3-azaspiro[5.5]undecane-1,5-dicarbonitrile

Abstract

Sequential reaction of cyclohexanone with malononitrile and2-aminopropene-1,1,3-tricarbonitrile in the presence of potassium hydroxide orsodium ethylate in ethanol gave4-imino-2-(dicyanomethylene)-3-azaspiro[5.5]undecane-1,5-dicarbonitrile. Thelatter reacted with primary amines and an excess of formaldehyde to form new2-(dicyanomethylene)-3,7-diazaspiro[bicyclo[3.3.1]non-3-ene-9,1′-cyclohexane]-1.5-dicarbonitrilederivatives. Contrary to the literature data, the reaction of cyclohexanone with2-aminopropene-1,1,3-tricarbonitrile in benzene in the presence of piperidineand glacial acetic acid led to the formation of2,4-diamino-5,6,7,8-tetrahydronaphthalene-1,3-dicarbonitrile