C-Substituted maleimides 2, 4, 6 are thiated with the reagent 1 in toluene or xylene. Monothiation at the nonequivalent carbonyl groups occurs in a regiospecific way. Maleimides 2, 4 with 4-methylphenyl or dialkylamino groups are attacked on the carbonyl function which is far from the C-substituent and give the monothiocompounds 3 and 5. The thiation of maleimides 6a-6b with NH-groups on the double bond primary occurs on the ...
