Open Vessel and Cooling while Heating Microwave-Assisted Synthesis of Pyridinyl N-Aryl Hydrazones

We reported the first example of open vessel and cooling while heating microwave-assisted synthesis of pyridinyl N-aryl hydrazones. Compounds were prepared in excellent isolated yields (88-98%) in only 5 min, by reacting 4- and 2,4-(di) substituted phenylhydrazines, bearing both electron-donating (4-CH3, 4-OCH3) and -withdrawing (4-Cl, 4-Br, 4CF(3), 4-NO2, 2,4-Cl-2) groups with 2-, 3-, and 4-acetylpyridine. The method was successfully extended to other carbonyl compounds.