USE OF TIAMULIN FOR PREPARING A DRUG FOR USE AS A CANCER MULTIDRUG RESISTANCE REVERSION AGENT

摘要

(57) Abstract(I) a compound represented by the following formula II: And the following formula III: Of an acrylonitrile derivative from a first organic solvent (1) forming an azeotrope with water or a lower alcohol and a second polar organic solvent (2) having a boiling point lower than the boiling point of the solvent (1) In the presence of a quaternary ammonium hydroxide catalyst, (ii) removing the second solvent (2) by distillation, (iii) allowing the reaction medium to solidify Adding water and / or lower alcohol in an amount sufficient for azeotropically distilling all of the solvent (1), and then distilling out all of the solvent (1), and (iv) obtaining Hydrolyzing the suspension obtained by adding a strong base or a strong acid to the reaction medium and optionally converting the carboxylate salt of the formula I obtained into the corresponding carboxylic acid, (Where X, i, j, R₁, R₂, R₃And R₄Is as defined in claim 1).