DIHALO PGI2 AND ITS PREPARATION

摘要

NEW MATERIAL:A dihalo PGI2 expressed by formulaI(R<1> is H or 1-10C alkyl; R<2> and R<3> are H or a protecting group of OH; X is Cl or Br; R<4> and R<5> or R<5> and R<6> together represent single bond and the rest is H) or a salt of the acid when R<1> is H. EXAMPLE:5,7-Dichloro PGI2 methyl ester 11,15-bis-tert-butyldimethylsilyl ether. USE:A medicine, stable under neutral - weakly acidic conditions, having improved chemical stability of the PGI2 and further inhibitory action on the blood platelet agglutination, hypotensive action and relaxing action on the smooth muscles, etc. and an intermediate for other compounds. PROCESS:A compound of formula II (R<11> is R<1> except H; R<21> and R<31> are R<2> and R<3> except H) is reacted with a compound of formula III, and if necessary the protecting groups are removed or the resultant compound is hydrolyzed and/ or subjected to the salt forming reaction to afford the compound of formulaIor a salt thereof.