| abstract |
Preparation procedure for (11β, 16α) -9-fluoro-11-hydroxy-16,17- [1-methyl-ethylidenebis (oxy)] - 21- [1-oxo- [4- (nitroxymethyl) benzoxy]] pregna-1,4-dien-3,20-dione.n n n The present invention relates to a new method of preparing the (11?, 16? -9-fluoro-11-hydroxy-16, 17- [1-methyl-ethylidenebis (oxy)] - 21- [1-oxo- [4- (nitroxymethyl) benzoxy]] pregna-1,4-dien-3,20-dione, comprising the steps of (i) reacting triamcinolone acetonide with 4- (nitroxymethyl) benzoic, 4-dimethylaminopyridine and N, N'-diisopropylcarbodiimide, ( ii) crystallization, and (iii) controlled precipitation. |