Triaryl methane composition, dye composition for ocular membrane dyeing

Abstract

A composition containing Brilliant Blue G (BBG) or a pharmaceutically acceptable salt thereof, and a positional isomer of Brilliant Blue G (BBG) or a pharmaceutically acceptable salt thereof, the composition containing 90 wt % or more and 100 wt % or less of one or both of Brilliant Blue G (BBG) and the pharmaceutically acceptable salt thereof in the total of the Brilliant Blue G (BBG), the pharmaceutically acceptable salt of Brilliant Blue G (BBG), the positional isomer of Brilliant Blue G (BBG), and the pharmaceutically acceptable salt of the positional isomer of Brilliant Blue G (BBG), a method for producing said composition, and a method of removing the ocular membrane of a human patient.

What is claimed is: 
     
         1 . A method for producing Brilliant Blue G (BBG) or a pharmaceutically acceptable salt thereof comprising:
 (a) making the ethyl-m-tolyl-amine of formula B1 react with a benzylation reagent to which a halogen atom is added, to yield a halogenated compound of formula B2;   (b) replacing the halogen atom of the halogenated compound of formula B2 to yield a benzyl ethyl-m-tolyl-amine derivative of formula B3;   (c) reacting the benzyl ethyl-m-tolyl-amine derivative of formula B3 with alkali to obtain a benzyl ethyl-m-tolyl-amine of formula B4; and   (d) obtaining Brilliant Blue G (BBG) of formula (1) or a pharmaceutically acceptable salt thereof from the benzyl ethyl-m-tolyl-amine derivative of formula B4   
       wherein B1, B2, B3, and B4 are: 
       
         
           
           
               
               
           
         
       
       wherein: X 21  is halogen; X 22  is halogen; and X 23  is hydrogen or a hydroxyl group wherein hydrogen is optionally replaced with an alkali metal or halogen. 
     
     
         2 . The method of  claim 1 , wherein the step of replacing halogen in the halogenated compound of formula B2, and thereby obtaining a benzyl ethyl-m-tolyl-amine derivative of formula B3 comprises:
 (a) making a sulfide act on the halogenated compound of formula B2 to obtain a compound of formula B2-1; and   (b) making an electrophilic reagent SO 2 Cl 2  act on the compound of formula B2-1 to obtain the benzyl ethyl-m-tolyl-amine derivative of formula B3 wherein X 21  is chlorine   
       
         
           
           
               
               
           
         
       
       wherein R 21  is phenyl, benzyl, methyl, ethyl, or hydroxyl, or wherein phenyl or benzyl is replaced by halogen. 
     
     
         3 . The method of  claim 1 , wherein step (b) comprises:
 (a) making a Grignard reagent act on the halogenated compound of formula B2,   (b) making SO 2  act thereon, and   (c) then making a halogen ion act thereon to obtain the benzyl ethyl-m-tolyl-amine derivative of formula B3.