4-甲基-4-氮杂-21E-苯亚甲基-5-孕烯-3,20-二酮类化合物的合成

Synthesis of 4-Methyl-4-aza-21E-benzylidene-5-pregnene-3,20-dione

报道了一种以KF/Al_2O_3催化合成4-甲基-4-氮杂-21E-苯亚甲基-5-孕烯-3,20-二酮类化合物的方法。以黄体酮为原料,经NaIO_4/KMnO_4氧化裂解、胺解关环得到重要中间体4-甲基-4-氮杂-5-孕烯-3,20-二酮,后者在KF/Al_2O_3催化下经克莱森缩合得到目标产物。考察了不同的催化剂、反应温度、催化剂用量对目标产物的影响。条件优化的结果为:n(3)∶n(KF/Al_2O_3)=1∶1,回流状态下反应4 h,产率为56%~68%。此方法适用性好,为4-氮杂甾体苯亚甲基衍生物的合成提供了一种方便而有效的方法。

The method of synthesis of 4-methyl-4-aza-21E-benzylidene-5-pregnene-3,20-dione catalyzed by KF/Al2O3was reported. 4-Methyl-4-aza-5-pregnene-3,20-dione, as a key intermediate, was synthesized by cleavage.of A-ring and ring-closure from progesterone and which was then converted to the target product through Claisen condensation catalyzed by KF/Al2O3. The effects of different catalysts, reaction temperature and catalyst dosage were investigated. 56% - 68% yields are obtained under optimal conditions ：n （3）：n （KF/ Al2O3 ） = 1 ： 1, reaction time 4 h under reflux. This study provides a simple and efficient approach to the synthesis of 4-aza-steroidal benzylidene derivatives.