Treatment of methyl 2-cyano-3-methylthio-4-nitrocrotonate with conc. sulfuric acid gave 2-carbamoyl-3-methylthio-2-buten-4-olide (II) in a good yield. This compound (II) was formed easily by the replacement reaction between methylthio group and nucleophilic reagents such as amines or active methylene compounds. Condensation reaction of II as a nucleophilic reagent with various reagents having a formyl or ketone group gave corresponding condensation products. Reaction of II with quinoline 1-oxide gave 2-carbamoyl-3-methylthio-4, 4-bis (2-quinolyl)-2-buten-4-olide (X).
                                    用浓
硫酸处理 2-
氰基-3-甲
硫基-4-硝基
巴豆酸甲酯,可以得到 2-
氨基甲酰基-3-甲
硫基-
2-丁烯-4-内酯(II),收率很高。这种化合物(II)很容易通过甲
硫基和亲核试剂(如胺或活性亚甲基化合物)之间的置换反应生成。II 作为亲核试剂与各种具有甲酰基或酮基的试剂发生缩合反应,可得到相应的缩合产物。II 与
喹啉 1-氧化物反应生成 2-
氨基甲酰基-3-甲
硫基-4,4-双(2-
喹啉基)-
2-丁烯-4-内酯(X)。