ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Methyltrioxorhenium-catalysed oxidation of secondary amines to nitrones in ionic liquids

Mária Mečiarová, Melinda Mojzesová, and Radovan Šebesta

Department of Organic Chemistry, Faculty of Natural Sciences, Comenius University, Mlynská dolina CH-2, 842 15 Bratislava, Slovakia

E-mail: radovan.sebesta@fns.uniba.sk

Abstract: Nitrones serve as starting materials for the synthesis of many heterocycles. Oxidation of secondary amines using hydrogen peroxide and the catalytic amount of methyltrioxorhenium in ionic liquids is a useful method for the preparation of nitrones. Ultrasonic irradiation and ionic liquids have a positive influence on the reaction. The nitrones required were isolated in good yields. Corresponding hydroxylamines, which can be easily oxidised to nitrones, often accompanied the main products. Methyltrioxorhenium in ionic liquids was re-used in several reaction cycles without any deteriorating effect on the course of the reaction.

Keywords: nitrone – amine – methyltrioxorhenium – oxidation – ionic liquid

Full paper is available at www.springerlink.com.

DOI: 10.2478/s11696-012-0208-5

Chemical Papers 67 (1) 51–58 (2013)