Abstract
Nanocrystalline magnesium oxide (NAP-MgO) was found to be an effective heterogeneous, solid base catalyst for the direct aza-Henry reaction of nitroalkanes and various N-arylidene-4-methylbenzenesulfonamides to afford the corresponding β-nitroamines in excellent yields under mild conditions. The catalyst was recovered by simple centrifugation and reused for three cycles with consistent activity.
ACKNOWLEDGMENTS
We thank the Council of Scientific and Industrial Research (CSIR) for financial support under the Task Force Project CMM-0005. L. C. P. thanks the CSIR, India, for providing a senior research fellowship.
Notes
a Conditions: catalyst (10 mg), N-(4-chlorobenzylidene)-4-methylbenzene-sulfonamide (0.25 mmol), nitromethane (10 equiv.).
b Isolated yields.
a Conditions: NAP-MgO (10 mg), N-(4-chlorobenzylidene)-4-methyl-benzenesulfonamide (0.25 mmol), nitromethane (10 equiv.), solvent (2 mL).
b Isolated yield.
a Conditions: Catalyst (10 mg), N-arylidene-4-methylbenzene sulfonamide (0.25 mmol), nitroalkane (10 equiv.), DMF (2 mL).
b Isolated yields.
c Yield after third cycle.