Unsymmetrically substituted thioureas and ethyl (E)- and (Z)-3-aryl-3-chloro-2-cyano- propenoates (1a) and (1b) gave after nucleophilic vinylic substitution and cyclisation two isomers of 1,3-disubstituted 6-aryl-5-cyano-2-thiouracil derivatives, 3a-3i and 4a-4i. Substituted 1,3-thiazin-4-ones 5a-5d were formed in moderate to good yields when monosubstituted thioureas were allowed to react under similar conditions.
非对称取代硫脲和乙基(E)-和(Z)-3-芳基-3-氯-2-氰基丙烯酸乙酯(1a)和(1b)在亲核乙烯取代和环化后形成了1,3-二取代6-芳基-5-氰基-2-硫脲衍生物的两个异构体,3a-3i和4a-4i。当单取代硫脲在类似条件下反应时,取代的1,3-噻唑-4-酮5a-5d以中等至良好的产率形成。