Hydrochloric Acid → 2-{4-[2-(4-Chlorocinnamoylamino)-ethyl]-phenoxy}-2-methyl-propionic acid

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Reaction Steps

A solution of 119.1 g. (0.407 mol) ethyl 2-[4-(2-acetaminoethyl)-phenoxy]-2-methylpropionate in 750 ml. ethanol is mixed with a solution of 224.4 g. (4.00 mol) potassium hydroxide in 800 ml. water and heated under reflux for 8 hours. While cooling, there are then added exactly 4.00 mol hydrogen chloride (for example, in the form of 2 N hydrochloric acid), cooling is intensified and, after some time, the crystals which separate out are filtered off with suction. These are washed with water and dried; there are obtained 48.4 g. of product (53% of theory) which melts, with decomposition, at 274° C. From the mother liquor there are obtained, after distilling off the ethanol and cooling, a further 32.5 g. (36% of theory) of product with a melting point of 263°-270° C. The crude 2-[4-(2-aminoethyl)-phenoxy]-2-methylpropionic acid obtained is recrystallised from ethanol and water (4:1 v/v) and then has a melting point of 284° C. The corresponding hydrochloride has a melting point of 187°-189° C.

Provenance & Evidence