| abstract |
This invention relates to a new process for preparing (11 β, 16α)-9-fluoro-11 - hydroxy-16,17-[1 -methyl -ethyl idenebis(oxy)]-21 -[1 -oxo-[4- (nitrooxymethyl)benzoxy]]pregna-1,4-dien-3,20-dione, comprising the steps of (i) reaction of triamcinolone acetonide with 4-(nitrooxymethyl)benzoic, 4- dimethylaminopyridine and N-N'-diisopropylcarbodiimide, (ii) crystallisation, and (iii) controlled precipitation. |