Hydrogen Peroxide → 2-[6-Fluoro-2-methyl-3-[(4-methylsulfonylphenyl)methylidene]inden-1-yl]acetic acid

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

5-fluoro-2-methyl-1-(ρ-methylsulfonylbenzylidene)-3-indenyl acetic acid is prepared by adding sodium methoxide (4.4M in MeOH, 68.5 ml, 0.3 mol) dropwise to a stirred cooled mixture of 5-fluoro-2-methyl-1-(ρ-methylsulfinylbenzylidene)-3-indenyl acetic acid (100 g, 0.281 mol) in methanol (250 ml) and acetonitrile (500 ml). Sodium bicarbonate (0.56 mol) and hydrogen peroxide (30% in water, 0.56 mol) are added and allowed to react for 18 hours at -10° C. Excess sodium bicarbonate is filtered off, and cooled filtrate (0° C.) neutralized dropwise to pH 7 with 1M hydrochloric acid (350 ml). The resulting product is then filtered and washed with methanol. A thin layer chromatography system to check for purity utilizes chloroform:methyl isobutyl ketone (8:2); the Rf value is 0.21. A tetrahydrofuran/diisopropyl ether combination can be used for product recrystallization. Reaction yield is 89%. The product has a mp of 205°-206° C. (R1 =hydrogen; R2 =CH3 ; R3 =5-fluoro; R4 =hydrogen; R5 =CH3SO2 --)

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