Stent coated by a compound

Abstract

A stent coated by a compound represented by the general formula (1) below which is produced by reaction between rapamycin and alkyl triflate in an organic solvent which is a chlorine-containing organic solvent, wherein said reaction is carried out in the presence of trialkylamine, where R denotes alkyl, arylalkyl, hydroxyalkyl, alkoxyalkyl, acyloxyalkyl, aminoalkyl, alkylaminoalkyl, alkoxycarbonylaminoalkyl, acylaminoalkyl, or aryl.

1 . A stent coated by a compound represented by the general formula (1) below which is produced by reaction between rapamycin and alkyl triflate in an organic solvent which is a chlorine-containing organic solvent, wherein said reaction is carried out in the presence of trialkylamine,  
     
       
         
         
             
             
         
       
     
     where R denotes alkyl, arylalkyl, hydroxyalkyl, alkoxyalkyl, acyloxyalkyl, aminoalkyl, alkylaminoalkyl, alkoxycarbonylaminoalkyl, acylaminoalkyl, or aryl.  
   
   
       2 . The stent as defined in  claim 1 , wherein the trialkylamine is used in an amount not less than 30 mol per mol of rapamycin.  
   
   
       3 . The stent as defined in  claim 1 , wherein the trialkylamine is N,N-diisopropylethylamine.  
   
   
       4 . The stent as defined in  claim 1 , wherein the chlorine-containing organic solvent is methylene chloride or chloroform.  
   
   
       5 . The stent as defined in  claim 1 , wherein the organic solvent is used in an amount of 2 to 6 parts by weight for 1 part by weight of rapamycin.  
   
   
       6 . The stent as defined in  claim 1 , wherein the alkyl triflate is used in an amount of 5 to 20 mol per mol of the compound represented by formula (1).  
   
   
       7 . The stent as defined in  claim 1 , wherein the alkyl triflate is 2-ethoxyethyl triflate.  
   
   
       8 . The stent as defined in  claim 1 , wherein the compound is produced by an additional step for purification in which the compound represented by formula (1) is placed in a mixed solvent comprising water and at least one water-miscible solvent or placed in water or a water-containing mixed solvent after dissolution in at least one water-miscible solvent, and subsequently allowed to precipitate out.  
   
   
       9 . The stent as defined in  claim 8 , wherein the water-miscible solvent is used in an amount of 2 to 10 parts by weight for 1 part by weight of the compound represented by formula (1).  
   
   
       10 . The stent as defined in  claim 8 , wherein the water is used in an amount not less than 10 parts by weight for 1 part by weight of the compound represented by formula (1).  
   
   
       11 . The stent as defined in  claim 8 , wherein the water-miscible solvent is an alcohol.  
   
   
       12 . The stent as defined in  claim 11 , wherein the alcohol is methanol.  
   
   
       13 . The stent as defined in  claim 8 , wherein the step of precipitation is carried out such that the compound represented by formula (1) is dissolved in a solvent containing at least one water-miscible solvent and subsequently the resulting solution is placed in water or a mixed solvent comprising water and at least one water-miscible solvent.