Unexpected efficient reactions of nitrogen nucleophiles with α,β-unsaturated nitriles / esters
Keywords:Knoevenagel condensation,α,βunsaturated nitrile, azine derivative, hydrogenation of C=C, hydrazinium sulphate, o-phenylenediamine
α,β-Unsaturated compounds containing aldehyde, ketone, nitrile and ester functional groups are versatile precursor for the synthesis of novel organic molecules. All these compounds undergo Michael addition of carbon and other nucleophiles at b-carbon atom of the a,b-unsaturated system. Different carbo- and hetero-cyclic compounds can be synthesized by varying the conditions of cyclisation of the Michael adducts. In this context, it is planned to synthesize pyrazole derivatives and diazepine derivatives by reacting a,b-unsaturated compounds with different Nitrogen nucleophiles such as, o-phenylenediamine etc. The present investigation reports the unexpected hydrogenation of C=C in a,b-unsaturated nitriles and the unexpected synthesis of azine derivatives from a,b-unsaturated nitrileand hydrazinium sulphate.