6a-Fluoro-triamcinolone

To a suspension of 500 mg of 6a-fluoro-triamcinolone in 75 ml of acetone is added 0.05 milliliters of 72% perchloric acid and the mixture agitated at room temperature for 3 hours. During this period the crystals gradually dissolve and the clear solution is neutralized with dilute bicarbonate and the acetone removed in vacuo. The resulting crystalline suspension is filtered and the crystals washed with water. The dried material is recrystallized from 95% alcohol to give the pure acetonide. 

A solution of 50 mg of 6a-fluoro-triamcinolone acetonide in 1 ml of pyridine and 1 ml of acetic anhydride is allowed to stand at room temperature for 18 hours. Removal of the reagents in vacuo gives a crystalline residue which after crystallization from acetone-hexane gives the pure 16a,17a-isopropylidene 6o -fluoro-triamcinolone 21 acetate (fluocinonide), as described in U.S. Patent 3,197,469. 

Names synonyms TRIAMCINOLONE ACETONIDE 9 -fluoro- ip,2 dihydroxy-16a. 17a-isopropylidene-dioxy-1.4-pregnadiene-3.20-dione 9a-fluoro-l 6a-hydroxyprednisolone 16.17-acetonide. TRIAMCINOLONE DIACETATE 16a.21 -diacetoxy-9a-fluoro-11 17a-dihydroxy-1.4-pregnadiene 3.20-dione 9a-fluoro-16a-hydroxypredni olone 16.21 -diacetaie. 

Many synthetic corticoids were introduced following the discovery of triamcinolone. These include triamcinolone 16,17-acetonide, 6o -methylprednisolone, 16a -methyl-9o -fluoroprednisolone (dexamethasone), 16 -methyl-9a(-fluoroprednisolone (betamethasone), 6o -fluoro-16a-methylprednisolone (paramethasone), 16-methylene-prednisolone, and 6a, 9a -dlfluoro-16a-hydroxyprednisolone 16,17-acetonide (fluocino-lone acetonide). Microbiology played no essential role in their discovery, although in some cases microbiological technology has been employed to advantage in their manufacture. 

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