Sodium Hydroxide → HCID 20478031, compound

Participants

Reaction Steps

22.6 g of the 1-[2-[2-(2-chlorophenyl)-2-imidazolin-1-yl]-ethyl]-3-(4-ethoxycarbonyl-phenyl)-urea hydrochloride obtained according to Example 19 are dissolved in 900 ml of 95% alcohol and the base is liberated with 50 ml of 1 N sodium hydroxide solution. After adding 200 ml of 2 N sodium hydroxide solution, the mixture is stirred overnight. It is then neutralised with 200 ml of 2 N hydrochloric acid and slightly acidified with 51 ml of 1 N hydrochloric acid. The resulting mixture is evaporated to dryness in a rotary evaporator and the residue is twice boiled thoroughly with 100 ml of alcohol. The residue consists of sodium chloride; after substantial concentration, the solution yields crystalline 1-[2-[2-(2-chlorophenyl)-2-imidazolin-1-yl]-ethyl]-3-(4-carboxyphenyl)-urea hydrochloride, which is recrystallised from methanol/isopropanol and then melts at 240°-242° with decomposition.

Provenance & Evidence