Pyrido[2,3-<i style="mso-bidi-font-style:normal">d</i>]pyrimidines: A novel tandem Michael cyclization of 6-aminouracils with arylidenecyanoacetate using BiCl₃

728-7321,3-Dimethyl-2,4,7-trioxo-5-aryl-1,2,3,4,7,8-hexahydropyrido[2,3-d]pyrimidine-6-carbonitriles have been synthesized via tandem Michael-Cyclization of 6-aminouracils with arylidene ethylcyanoacetates employing catalytic amount of BiCl3. Under mild reaction conditions, pyrido[2,3-d]pyrimidines have been obtained in very good yields in one pot