33 35'(a) R'NH2, EtOH, room temperature;(b) NaH in dioxane or K2 C03 in acetone, or NBulF in THF;(c) NaOH, H20;(d) piperazine, fluoroaroyl)-3-ethoxyacrylate 29 with a slight excess of an appropriate amine in ethanol at room temperature gives the corresponding enamino keto ester 30, usually as a crystalline product. Cyclization of 30 (X= CH), by heating with sodium hydride in dioxane, gives ethyl 1, 4-dihydro-4-oxoquinoline-3-carboxylate. ...