AbstractThe reactions of ethyl (1,4‐dihydro‐4‐oxoquinazolin‐2‐yl)acetate4and 2‐aminoquinazolin‐4(1H)‐one5with diethyl ethoxymethylenemalonate (EMME), (ethoxymethylene)malononitrile (EMMN) and ethyl (ethoxymethylene)cyanoacetate (EMCA) are reported, and rather different results are obtained to those previously found with quinoline analogs. Reaction of 4 with EMME gives a pyrido[1,2‐a]quinazoline, while with EMMN and EMCA ethyl 2‐(pyridin‐2‐yl)aminobenzoates are formed, presumably by ring‐opening of intermediate pyrido[2,1‐b]quinazolines. Reaction of 5 with EMME likewise results in ultimate cyclization onto N‐1 of the quinazoline, while the EMMN and EMCA reactions give isolable pyrimido[2,1‐b]quinazolines. These are readil