PREPARATION OF CINNOLINE-3,4-DICARBONITRILE AND -DICARBOXYLIC ACID

Article abstract of DOI:10.1016/S0040-4020(01)88907-9

Attempts to prepare cinnoline-3,4-dicarboxylic acid from 3,4-dimethylcinnoline failed owing to the unreactivity of the 3-Me group.Successive treatment of 3-bromo-4-chlorocinnoline with sodium toluene-p-sulphinate and potassium cyanide in dimethylformamide (DMF) gave 4-toluene-p-sulphonylcinnoline-3-carbonitrile and then cinnoline-3,4-dicarbonitrile (82percent).Hydrolysis yielded cinnoline-3,4-dicarboxylic acid (53percent).Cinnoline-3,4-dicarbonitrile undergoes nucleophylic displacement of either the 4- or the 3-cyano group by ammonia or amine to give 4-amino- and 4-benzylaminocinnoline-3-carbonitrile but 3-dimethylamino-cinnoline-4-carbonitrile.