Zn(Proline)2-catalyzed Knoevenagel condensation under solvent-free/aqueous conditions and biological evaluation of products
作者:Zeba N. Siddiqui、T. N. Mohammed Musthafa、Shagufta Praveen、Farheen Farooq
DOI:10.1007/s00044-010-9376-4
日期:2011.12
A novel approach was adopted for the synthesis of series of Knoevenagel condensation products from 5-chloro-3-methyl-1-phenylpyrazole-4-carboxaldehyde with different cyclic active methylene compounds, using water soluble and recyclable Zn(Proline)(2) as a Lewis acid catalyst both under solvent-free condition and using water as a reaction medium in good yields. In each conversion, the catalyst was successfully recovered and recycled without significant loss in yield and selectivity. The compounds were screened for their antimicrobial activity.
P2O5/SiO2 as an efficient heterogeneous catalyst for the synthesis of heterocyclic alkene derivatives under thermal solvent-free conditions
作者:Zeba N. Siddiqui、Tabassum Khan
DOI:10.1039/c3cy00095h
日期:——
A highly efficient methodology is developed for the synthesis of a series of heterocyclic alkene derivatives 3a–k from 5-chloro-3-methyl-1-phenylpyrazole-4-carboxaldehyde 1 and active methylene compounds 2a–k, in the presence of P2O5/SiO2, under thermal solvent-free conditions, in high yields, within a short reaction time. The catalyst is characterized for the first time by using X-ray diffraction