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ChemicalBook CAS DataBase List Triamcinolone
124-94-7

Triamcinolone synthesis

9synthesis methods
Triamcinolone, 9a-fluoro-11b,16a,17,21-tetrahydroxypregna-1, 4-dien-3,20-dione (27.1.61), differs from dexamethsone in terms of chemical structure in that the a methyl group at C16 is replaced with a hydroxyl group. It is synthesized from the 21-O-acetate of hydrocortisone 27.1.17. In the first stage, both carbonyl groups of this compound undergo ketalization by ethylene glycol. Next, the hydroxyl group in the resulting diketal 27.1.53 is replaced with chlorine using thionyl chloride, and the product undergoes dehydrochlorination using an alkaline, during which the 21-O-acetyl group also is hydrolyzed. Acetylating the hydroxyl group once again with acetic anhydride gives a triene 27.1.54. Reacting this with osmium tetroxide gives the vicinal diol 27.1.55. The secondary hydroxyl group at C16 of this product undergoes acetylation by acetic anhydride in pyridine, which forms the diacetate 27.1.56. Treating the product with N-bromoacetamide in chloric acid gives a bromohydrin (27.1.57), which upon reaction with potassium acetate is transformed to an epoxide (27.1.58). Opening of the epoxide ring, using hydrofluoric acid, gives the corresponding 9-fluoro-11-hydroxy derivative 27.1.59. Upon microbiological dehydrogenation, the C1–C2 bond is oxidized to a double bond, forming triamcinolone acetate (27.1.60), the acetyl group of which is hydrolyzed, forming the desired triamcinolone (27.1.61).

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Yield:124-94-7 85.29%

Reaction Conditions:

with sodium hydroxide in methanol;dichloromethane at -7 - -3;Inert atmosphere;

Steps:

7.IV Stage - IV (Preparation of Triamcinololne from Stage -III)
24gm of stage-Ill (0.055mol) was dissolved in 240ml of methanol (lOvolume) and 240ml of methylene chloride (lOvolume) mixture under argon bubbling. Cool to -5°C+2°C and added 0.48gm of sodium hydroxide (0.012mol) solution in 24ml of methanol (Olvolume) at - 5°C+2°C. Reaction was maintaining at -5°C (+2°C) for 03hours. In-process check by TLC against stage-Ill, it should be nil. Adjust pH neutral by adding 0.70ml of acetic acid at -5°C (+2°C). Reaction mass distilled at below 40°C under vacuum till 04-05 volume of input. Cooled to 0°C+5°Cand stir for one hour than filtered and washed with minimum precooled methanol. Wet material was dried at 45°C to 50°C till moisture content less than 0.50%. Yield=18.50gm, (85.29%), HPLC Purity=98.60%.

References:

CORAL DRUGS PVT. LTD.;TRIPATHI, Vinayak;KUMAR, Rajesh;BHUWANIA, Rohit;BHUWANIA, Binay Kumar WO2016/120891, 2016, A1 Location in patent:Page/Page column 26

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