Abstract
Grinding a mixture of 6-aminopyrimidine-2,4(1H,3H)-dione 1a or 6-amino-2-thioxo-2,3-dihydropyrimidine-4(1H)-one 1 b or ethyl 7-amino-5-oxo-1-aryl-1,5-dihydro[1,2,4]-triazolo[4,3-a]pyrimidine-3-carboxylate derivatives 5a-c with 1,2-diphenylethanone 2 and aromatic aldehydes 3a-j in the presence of aluminate sulfonic acid nanoparticles (ASA NPs) in a one pot solvent-free conditions, afforded the pyrido[2,3-d]pyrimidinone derivatives 4a-o and ethyl 5-oxo-1-aryl-6,7,8-triphenyl-1,5,6,9-tetrahydropyrido[2,3-d][1,2,4]triazolo[4,3-a]pyrimidine-3-carboxylate derivatives 6a-c, respectively. High yields, short reaction time, easy workup, inexpensive, and reusability of the catalyst are advantages of this method. All structures were elucidated by spectral and elemental analyses. Structures of 6a-c were further proved by alternative synthesis of 6a.