Synthesis of Novel Indeno[1,2‐d]pyrimidine‐2,5(3H)‐diones and Their Thioxo Analogs Using Palladium on Charcoal as an Oxidizing Reagent

Treatment of 4‐methyl‐1H‐indeno[1,2‐d]pyrimidine‐2,5(3H, 9bH)‐dione derivatives 1(a–e) or 2,3‐dihydro‐4‐methyl‐2‐thioxo‐1H‐indeno[1,2‐d]pyrimidine‐5(9bH)one 1(f–j) with palladium on charcoal in diphenyl ether gave the dehydrogenated corresponding products 2(a–j), respectively. Yields of the products, after washing with ligroin, were of the order of 50–69%. ¹H‐NMR and ¹³C‐NMR spectroscopy and elemental analysis were used for identification of these compounds.

Keywords:

• pyrimidine
• indeno
• dione
• thioxo