Abstract
The condensation reaction of 3-heteroaromatic-3-oxopropanenitriles 3, 4 and 7 with dimethylformamide-dimethylacetal (DMF-DMA) gave the corresponding enaminones 8, 9 and 10, respectively. Nucleophilic substitution of 8 and 9 with different amines resulted in a new derivatives of enaminones 11-18. The reactivity of enaminones 8 and 9 toward some nitrogen nucleo-philes was investigated with a view to synthesize new heterocyclic systems. Thus, treatment of compounds 8 and 9 with phenylhydrazine afforded the pyrazole derivatives 19 and 20, respectively. On the other hand, reacting 8 and 9 with guanidine gave the pyrimidines 21 and 22, respectively. Treatment of compound 9 with hydroxylamine hydrochloride afforded the aminoisoxazoles 23. The foregoing reactions were carried out with conventional heating and under green conditions [ultrasound (US) irradiations or ionic liquids (ILs)] and a comparative study was employed. All the new structures are fully characterized. (C) 2013 King Saud University. Production and hosting by Elsevier B.V.