Reaction of N-(benzylideneamino) ephedrine (II) with benzylmagnesium chloride gave N-(1, 2-dimethylethylamino) ephedrine (a mixture of III and IV). On the other hand, reaction of N-[(2-phenylethylidene) amino] ephedrine (VII) with phenyllithium gave IV. Hydrogenolysis of these products gave 1, 2-diphenylethylamine with 40% (S) and 91% (R) optical purity, respectively, and l-ephedrine used as a chiral auxiliary reagent was recovered. Reactions of N-(arylmethylideneamino) ephedrines (VIII and IX) with benzylmagnesium chloride gave chiral hydrazines (X and XI), and reactions with phenyllithium gave XII and XIII.
N-(benzylideneamino) ephedrine (II) 与
苄基氯化镁反应生成 N-(1,2-二甲基乙基
氨基) ephedrine(III 和 IV 的混合物)。另一方面,N-[(2-苯基亚乙基)
氨基]
麻黄碱(VII)与
苯基锂反应生成 IV。氢解这些产物可得到 1,2-二苯基
乙胺,光学纯度分别为 40%(S)和 91%(R),并回收了用作手性辅助试剂的 l-
麻黄碱。N-(芳基亚甲基
氨基)
麻黄碱(VIII 和 IX)与
苄基氯化镁反应生成手性
肼 (X 和 XI),与
苯基锂反应生成 XII 和 XIII。