KMITL

Permanent URI for this communityhttps://dspace.kmitl.ac.th/handle/123456789/1

Browse

Settings

Subject: search.filters.subject.isoindigos

Search Results

Now showing 1 - 2 of 2
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    DBU-Mediated Dimerization: Facile Access to 9,9′-Bifluorenylidenes and Isoindigos
    (2023-11-14)
    Purahong, Nitchakan
    ;
    Hongthong, Sakchai
    ;
    Chotsaeng, Nawasit
    ;
    Kuhakarn, Chutima
    ;
    Meesin, Jatuporn
    The present work describes the 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU)-promoted self-dimerization of 9-chlorofluorenes and 3-chlorooxindoles for the preparation of the corresponding 9,9 -bifluorenylidene and isoindigo derivatives in moderate to good yields of 29 97%. The reactions proceed readily in a short reaction time under mild and metal-free conditions. Scale-up syntheses (5.0 mmol) of selected 9,9 -bifluorenylidene derivatives proceed in decent yields, highlighting the synthetic utility of the reported protocol.
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    Dimerization of 3-Chlorooxindoles Mediated by Potassium Ethyl­xanthate: Synthesis of Isoindigos
    (2022-08-17)
    Meesin, Jatuporn
    ;
    Chotsaeng, Nawasit
    ;
    Kuhakarn, Chutima
    A 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.