Acetic acid Finasteride

Impinging jets, which consist of a cylindrical chamber with two spray nozzles that enter from opposite sides of the chamber, provide small particles with narrow size distribution. The solution oi the material is fed through one nozzle and the crystallization agent through the second nozzle. Finasteride has been cry.stallized in this way a solution of the material in acetic acid plus some water was fed from one nozzle and water from the other the average crystal size was 10 to 15 pm. 

Patent US 4,377,584, issued Mar. 22,1883, and J. Med. Chem., 29, 2298 (1986)). The resulting slurry was cooled to -5-10°C, and 27.6 mL of t-butylamine was added. A solution of ethylmagnesium bromide in THF (122 mL, 2 M) was added maintaining the temperature of the reaction mixture below 10°C. The reaction mixture was heated at reflux for 12 hours and was added to a cold (10°C) solution of 25% ammonium chloride in water. The mixture was warmed to 25°C and allowed to settle. The THF solution was separated and concentrated by atmospheric distillation to 200 mL and the product was crystallized by adding approximately 600 mL of dilute aqueous HCI. The resulting white solid was isolated by filtration and was dried at 70°C under vacuum to give 21.7 g (97% yield) 2-butyl-l-(4-carboxybenzyl)-4-chloroimidazole-5-acetic acid of finasteride. The finasteride can be purified by conventional procedures, e.g. recrystallization from methylene chloride/ethyl acetate or acetic acid/water, melting point 261°C. 

C2(,H2801 302-97-6) see Finasteride 3-oxo-4-aza-5a-androstane-17 i-carboxylic acid (CH1H29NO3 103335-55-3) see Finasteride 3-oxo-l,2-benzisothiazole-2(37/)-acetic acid ethyl ester 1,1-dioxide... 

Form I of finasteride can be produced by the addition of water to an acetic acid solution of finasteride such that the final weight % of water is equal to or exceeds 84%. If the weight % of water is less than 83%, acetic acid solvates (mono- and di-) of finasteride are obtained that convert to Form II of... 

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