A variety of heterocyclic systems linked to 1-ethylquinolin-2(1H)-one was prepared from reaction of 3-(nitroacetyl)-1-ethyl-4-hydroxyquinolin-2(1H)-one with some electrophilic and nucleophilic reagents. Besides its cyclization to 5-ethyl-2-(hydroxyimino)-2,3,4,5-tetrahydrofuro[3,2-c]quinoline-3,4-dione, the 3-(nitroacetyl)-1-ethyl-4-hydroxyquinolin-2(1H)-one has been brominated, chlorinated, formylated, acetylated, and condensed with chromone-3-carbonitrile and 2-amino-3-formylchromone. Some new pyrazolo[4,3-c]quinoline, pyrimido[5,4-c]quinoline and quinolino[4,3-b][1,5]benzodiazepine derivatives were also synthesized.
β-ketoacid; 3-nitroacetylquinolinone; pyrazolo[4,3-c]quinolinones; pyrimido[5,4-c]quinolinones; cyclocondensation
