申请人:E. R. Squibb & Sons, Inc.
公开号:US04734508A1
公开(公告)日:1988-03-29
A process is provided for preparing 4-hydroxy-4-phenyl-proline derivatives of the structure ##STR1## wherein R.sub.1 is a nitrogen protecting group such as benzoyl, benzyloxycarbonyl, t-butoxycarbonyl, benzyl, benzhydryl, trityl, acetyl, trifluoromethylacetyl, sulfonamides, and the like and wherein X is OR.sub.2 and R.sub.2 is hydrogen or an acid protecting group such as lower alkyl, aryl-lower alkyl or a metal ion, such as Na or K, or X is NR.sub.3 R.sub.4 wherein R.sub.3 and R.sub.4 may be the same or different and are hydrogen, lower alkyl, aryl or arylalkyl, or R.sub.3 and R.sub.4 together with the nitrogen to which they are attached form a 5-, 6- or 7-membered ring. The process includes the steps of forming triphenylcerium [(C.sub.6 H.sub.5).sub.3 Ce], for example, by reacting cerium trichloride (CeCl.sub.3) with phenyllithium, and reacting the triphenylcerium with the keto acid ##STR2## in the presence of an inert organic solvent such as tetrahydrofuran. The 4-hydroxy-4-phenyl-proline derivatives used in the preparation of 4-substituted proline derivatives which are employed for preparing certain angiotensin-converting enzyme inhibitors.
提供了一种制备4-羟基-4-苯基-脯氨酸衍生物的方法,其结构为##STR1##其中R.sub.1是氮保护基,例如苯甲酰、苄氧羰基、t-叔丁氧羰基、苄基、苯甲基、三苯甲基、乙酰、三氟甲基乙酰、磺酰胺等,其中X为OR.sub.2,R.sub.2为氢或酸保护基,例如较低的烷基、芳基-较低的烷基或金属离子,例如Na或K,或者X为NR.sub.3R.sub.4,其中R.sub.3和R.sub.4可以相同或不同,分别为氢、较低的烷基、芳基或芳基烷基,或R.sub.3和R.sub.4与它们连接的氮一起形成5、6或7元环。该方法包括以下步骤:通过将三苯基铈[(C.sub.6H.sub.5).sub.3Ce]与酮酸##STR2##在惰性有机溶剂(例如四氢呋喃)的存在下反应形成三苯基铈,例如通过将三氯化铈(CeCl.sub.3)与苯基锂反应。用于制备某些血管紧张素转化酶抑制剂的4-羟基-4-苯基-脯氨酸衍生物用于制备4-取代的脯氨酸衍生物。