PROCESS FOR PRODUCING 5,6,7-TRINOR-4,8-INTER-M-PHENYLENE PGI2 DERIVATIVES

摘要

The present invention provides a process for preparing 5,6,7-trinor-4,8-inter-m-phenylene PGI2 derivative ¢VII! using 3a,8b-cis-dihydro-3H-5,7-dibromocyclopenta¢b!benzofuran (1) as a starting material, as well as compounds of the formulae (8) and (11) which are intermediates for the preparation of the compound of the formula (1). (see fig. I) The processes of the present invention are useful for producing m-phenylene PGI2 derivatives on an industrial scale, which are useful as pharmaceuticals. The process of the present invention has higher yield and the operations (especially purification) are easier than conventional processes.