Ace Inhibitors - The Synthesis Process Of The Fosinopril Study

The development , mechanisms, clinic application and market of the angiotensin-converting enzyme inhibitor agents were briefly reviewedin this paper. Fosinopril is one of the representatives ACEI drug in the third generation, and we focused on the study of its synthesis.Retrosynthetically, fosinopril can be disconnected into two distinct fragments: trans-4-cyclohexyl-L-proline (2), and [R-(R*, S*)]-[2-methyl-l-Pro-pionyloxypropoxy]-(4-phrnylbutyl) phosphinyl] acetic acid (3). The synthetic processes of compound 2 and compound 3 were systemically studied separately. The compound 2 was obtained in an overall yield of 14.4% via seven steps by using trans-4-hydroxy-L-proline as the starting material. The compound 3 was obtained in an overall yield of 2.49% via eight steps by using phenyl chlorine as the starting material. Fosinopril was given by the condensation of compound 2 and compound 3 in a yield of 43%.The whole synthetic route of fosinopril has eighteen steps, involving some special reactions, such as the amino protection and deprotection, Grignard Reagent and its reactions, Birch reduction, organic phosphorus chemistry, chiral synthesis and split and so on. Finally, we were successful in synthesis of fosinopril in an overall yield of 6.2% (based on the synthetic route of compound 2).In conclusion, the synthetic process of fosinopril was studied indetail and was carried out. Most of intermediates and final product were identified by MS, NMR and their physical property. The work will be much benefit to approaching industrial production of fosinopril and synthesis of the fosinopril analogues.