A Rapid and Convenient Method for the Synthesis of Aldoximes under Microwave Irradiation Using in situ Generated Ionic Liquids

Oximes are highly crystalline materials and oximation is very efficient method for characterization and purification of carbonyl compounds. These compounds not only represent a useful series of derivatives of carbonyl compounds but also may be used as intermediates for the preparation of amides by the Beckmann rearrangement [1], nitrones [2], hydroximinoyl chlorides, nitrile oxide [3] and chi al α-sulfinyl oximes [4]. The usual method for preparation of oximes [5,6] involves treatment of carbonyl compounds with hydroxylamine hydrochlorides in a basic aqueous medium with adjusted pH. Application of microwave heating technique has been currently under intensive investigation [7] and has been recently reviewed [8]. The advantages of using microwave irradiation are: (a) decrease in the reaction time and (b) cleaner reaction with straightforward work-up. The coupling of microwave irradiation with ionic liquids enhance reaction rates due to the ionic character of ionic liquids which make them microwave active solvents with easier work-up and