1H‐Indeno1,2‐d]pyrimidine‐2,5(3H,9bH)‐dione derivatives 2(a‐i) and 2,3‐dihydro‐2‐thioxo‐1H‐indeno1,2‐d]pyrimidine‐5(9bH)‐ones 2(j‐q) were synthesized via an intramolecular Friedel‐Crafts reaction between the aryl and ester group of ethyl 6‐methyl‐4‐aryl‐2‐oxo‐1,2,3,4‐tetrahydropyrimidine‐5‐carboxylates 1a‐i , and their thioxo analogs using AlCl3 and acetyl chloride in nitrobenzene. Yields of the products, after washing with THF, were of the order of 45‐69%. IR and NMR spectroscopy together with elemental analysis were used for identification of these compounds.
