Regioselectivity in the multicomponent reaction of 5-aminopyrazoles, cyclic 1,3-diketones and dimethylformamide dimethylacetal under controlled microwave heating

Kamal Usef Sadek; Ramadan Ahmed Mekheimer; Tahany Mahmoud Mohamed; Moustafa Sherief Moustafa; Mohamed Hilmy Elnagdi

doi:10.3762/bjoc.8.3

Regioselectivity in the multicomponent reaction of 5-aminopyrazoles, cyclic 1,3-diketones and dimethylformamide dimethylacetal under controlled microwave heating

Beilstein J Org Chem. 2012:8:18-24. doi: 10.3762/bjoc.8.3. Epub 2012 Jan 4.

Authors

Kamal Usef Sadek¹, Ramadan Ahmed Mekheimer, Tahany Mahmoud Mohamed, Moustafa Sherief Moustafa, Mohamed Hilmy Elnagdi

Affiliation

¹ Chemistry Department, Faculty of Science, El-Minia University, El-Minia 61519, Egypt.

Abstract

The multicomponent reaction of 5-aminopyrazole derivatives with cyclic 1,3-dicarbonyl compounds and dimethylformamide dimethylacetal (DMFDMA) in DMF at 150 °C under controlled microwave heating afforded regioselectively 8,9-dihydropyrazolo[1,5-a]quinazolin-6(7H)-ones 6 rather than the corresponding dihydropyrazolo[5,1-b]quinazolin-8(5H)-ones 4.

Keywords: DMFDMA; aminopyrazoles; dimedone; regioselectivity.