Hydrochloric Acid → HCID 70194376, compound

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Reaction Steps

13.6 g of powdered anhydrous calcium chloride are added to a solution of 3-ethoxycarbonyl-4-(4-fluorophenyl)-4-(4-methanesulphonylphenyl)-3-butenoic acid, prepared in Example 43, in 500 ml of ethanol. The mixture is stirred at room temperature and a solution of 7.5 g of sodium borohydride in a mixture composed of 1.5 g of potassium hydroxide, 10 ml of water and 10 ml of ethanol is added dropwise while cooling with an ice bath. After 4 hours at room temperature, the reaction medium is cooled to 0° C. and 6 N hydrochloric acid solution is added dropwise. After extraction with dichloromethane, the organic phase is dried over magnesium sulphate and evaporated under vacuum and the residue is crystallised from isopropyl ether. The crystals obtained are recrystallized from methanol to give 5 g of 4-[1-(4-fluorophenyl)-1-(4-methanesulphonylphenyl)methylidene]-dihydrofuran-2-one in the form of a mixture (50/50) of the two isomers, (E) and (Z), which are crystals melting at 160-164° C.

Provenance & Evidence