Rapid, Efficient, and Room Temperature Synthesis of Nitrones in Excellent Yields over MgO under Solvent-Free Conditions

A large variety of C-aryl and C-alkyl nitrones were synthesized within 0.5-15 min via the condensation of aldehydes with N-(methyl, phenyl, or t-butyl)hydroxylamines over MgO by hand-grinding with an agate mortar. These reactions were investigated under different conditions and over different solid supports including basic alumina, montemorillonite, MgO, and molecular sieves (pore size 3 angstrom). In the more interesting cases, nitrones were prepared over MgO without heating and any catalyst. In this procedure, nitrones were prepared in a very short time, excellent yields, and good purity without using harmful solvents in the workup. (C) 2009 Wiley Periodicals, Inc. Heteroatom Chem 20:177-181, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20527