One pot synthesis of spiro pyrimidinethiones/spiro pyrimidinones, quinazolinethiones/quinazolinones, and pyrimidopyrimidines

Abstract

Abstract magnified image Condensation of cyclohexane‐1,3‐dione/barbituric acid, thiourea/urea, and aromatic aldehyde in the mole ratio of 1:1:3 in solventless reaction in presence of NiCl2/KI afforded 1,5‐diaryl‐3‐thioxo‐2,4‐ diazaspiro[5.5]undecane‐7,11‐dione/1,5‐diaryl‐2,4‐diazaspiro[5.5]undecane‐3,7,11‐trione analogues and 7,11‐diaryl‐9‐thioxo‐2,4,8,10‐tetraazaspiro[5.5]undecane‐1,3,5,‐trione/7,11‐diaryl‐2,4,8,10‐tetraazaspiro[5.5] undecane‐1,3,5,9‐tetraone analogues, respectively. The similar condensation of cyclohexane‐1,3‐dione/cyclohexanone, thiourea/urea, and aromatic aldehyde/heteroaromatic aldehyde in the mole ratio of 1:1:1 in refluxing methanol afforded 4‐aryl/heteroaryl‐2‐thioxo‐1,2,3,4,5,6,7,8‐octahydroquinazolin‐5‐one, 4‐aryl/heteroaryl‐1,2,3,4,5,6,7,8‐octahydroquinazoline‐2,5‐dione analogues and 4‐aryl/heteroaryl‐1,2,3,4,5, 6,7,8‐octahydroquinazoline‐2‐thione, 4‐aryl/heteroaryl‐1,2,3,4,5,6,7,8‐octahydroquinazolin‐2‐one analogues, respectively. Condensation of heterocyclic active methylene compound, barbituric acid, thiourea/urea, and aromatic aldehydes under similar set of conditions in 1:1:1 mole ratio was carried which afforded 5‐aryl‐7‐thioxo‐1,2,3,4,5,6,7,8‐octahydropyrimido[4,5‐d]pyrimidine‐2,4‐dione/5‐aryl‐1,2,3,4,5, 6,7,8‐octahydropyrimido[4,5‐d]pyrimidine‐2,4,7‐trione analogues. Similar condensation of an active methine compound, 2‐acetylcyclohexanone, thiourea/urea, and aromatic aldehydes in the mole ratio of 1:1:1 produced 5‐aryl‐1‐methyl‐3‐thioxo‐2,4‐diazaspiro[5.5]undec‐1‐en‐7‐one/5‐aryl‐1‐methyl‐2, 4‐diazaspiro[5.5]undec‐1‐ene‐3, 7‐dione analogues, the spiro compounds of entirely different kind. All these identifications and characterizations have been based on the elemental analysis and spectral data. J. Heterocyclic Chem., (2010).