3-(3,4-dichlorophenyl)-3-hydroxy-2H-isoindol-1-one; (3RS)-3-(3,4-dichlorophenyl)-3-hydroxy-2,3-dihydro-1H-isoindol-1-one; Chlorthalidone Dichloro Impurity; 3-(3,4-Dichlorophenyl)-3-hydroxyisoindolin-1-one; Chlorthalidone Dichloro Impurity; 3-hydroxyisoindolin-1-one, 3-(3,4-dichlorophenyl)-;(3RS)-3-(3,4-Dichlorophenyl)-3hydroxy-2,3-dihydro-1H-isoindol-1-one