Abstract
Treatment of cyanoacetanilide derivative 1 with tetracyanoethylene (2) in dioxane/triethylamine furnished 2-pyridone derivative 6. Aminopyridine 9 was obtained by cyclization of compound 1 with ketene dithioacetal 7/EtONa. Cyclocondensation of 1 with malononitrile and/or acetylacetone (1: 1 Mratio) gave pyridine derivatives 11 and 13. Ternary condensation of compound 1, aliphatic aldehydes and malononitrile (1: 1: 1 M ratio) yielded the 2-pyridones 20a and b. Bipyridines 22a-c were prepared by refluxing of compound 21 with active methylene reagents. Cyclization of chromene derivatives 24 and 28 with malononitrile produced the novel chromeno[3,4-c]pyridine 26 and pyrano[30,20: 6,7] chromeno[3,4-c] pyridine 29. (C) 2013 King Saud University. Production and hosting by Elsevier B. V. All rights reserved.