Novel synthesis of cis-nickel(II) 3-alkylimino-3-alkyl(or aryl)thio-1-arylpropenethiolates and their application to the preparation of 5-aryl-3-(arylthio)isothiazoles

Treatment of (E)-3-alkylamino-3-alkylthio-1-(thioaroyl)propenes 2 with Ni(OAc)2.4H2O in EtOH at room temperature gave cis-Ni(II)-3-alkylimino-3-alkylthio-1-arylpropenethiolates 3 in excellent yields. Heating a mixture of 3 and alkyl- or arylthiols in 1,2-dichloroethane gave new ketene S,N-acetals 4 having new alkyl- or arylthio groups depending on the thiols employed. For the first time, 5-aryl-3-(arylthio)isothiazoles were prepared from 2 with an arylthio group according to a known procedure.