Efficient continuous flow-synthesis of novel spiro-naphthalene-1,2'-[1,3,4]oxadiazol-4-ones

The highly efficient cycloaddition reaction of hydrazonyl chlorides with 2,3-dichloro-1,4-naphthoquinone yielded pharmaceutically important spiro-naphthalene-1,2'-[1,3,4]oxadiazol-4-ones with moderate to good yields under batch and flow synthesis methods. The obtained products were elucidated by IR, 1 H NMR, 13 C NMR, HRMS and single crystal X-ray diffraction technique (only for 6h ). The synthesized molecules have been subjected to theoretical analysis by quantum chemical calculations at B3LYP/6-31G(d,p) level, which provided supporting data for the experimental findings.