Microwave heating is used for the preparation of 1,4-dihydropyridines and then, in conjunction with UV irradiation, is used for the efficient oxidation of the 1,4-dihydropyridines to pyridines. The oxidation reactions are performed in a sealed vessel using oxygen as the oxidant and an electrodeless discharge lamp as the irradiation source.
A simple method for the oxidative aromatization of Hantzsch 1,4-dihydropyridines to the corresponding pyridines is reported using urea-hydrogen peroxide/maleic anhydride in acetonitrile.
报道了一种简单的方法,利用乙腈中的尿素-过氧化氢/马来酸酐,将Hantzsch 1,4-二氢吡啶氧化芳香化为相应的吡啶。