REACTION OF UNSATURATED AZLACTONES WITH SULFUR NUCLEOPHILES : SOME OBSERVATIONS

Unsaturated azlactones undergo thiolysis with toluene-α-thiol, but 2-substituted (Z)-4-o-acetoxybenzylidene-4,5-dihydrooxazol-5-ones form 3-acylaminocoumarins in the presence of triethylamine. Sodium sulfide in ethanol brings about ethanolysis of the 1,5 bond and deacetylation of an acetoxy group. (Z)-4-Benzylidene-4,5-dihydrooxazol-5-one reacts with potassium thiocyanate to give (E)-4(5)-benzylidene-2-thiohydantoin.