| abstract |
This invention relates to a group of compounds derived from 3,3-bis-(4-hydroxyphenyl)-2-indolinone having an effective laxative activity. The process for their preparation comprises reacting a substituted 3,3-bis-(4-hydroxyphenyl)-2-indolinone with a compound of the group comprising ethyl chloroformiate, chloracetyl chloride, acetyl chloride, acetyl anhydride, propionyl chloride, propionyl anhydride and chlorosulphonic acid (in pyridine). |