Meesin J.Chotsaeng N.Kuhakarn C.Mahidol University2023-06-182023-06-182022-09-01Synlett Vol.33 No.14 (2022) , 1317-132209365214https://repository.li.mahidol.ac.th/handle/20.500.14594/84171A novel dimerization of 3-chlorooxindoles promoted by potassium ethylxanthate to access isoindigo derivatives is described. The reactions proceeded readily at room temperature in short reaction times. A mechanistic study revealed that the 3-chlorooxindole is initially converted into O-ethyl S-(2-oxo-2,3-dihydro-1H-indol-3-yl) dithiocarbonate, which subsequently undergoes dimerization with elimination of arbon disulfide. In almost all cases, analytically pure isoindigos were isolated in moderate to good yields without a requirement for chromatographic purification.ChemistryArticleSCOPUS10.1055/a-1784-23042-s2.0-8512737815714372096