Phosgene → HCID 23347353, compound

Participants

Reaction Steps

With vigorous stirring, 630 ml of a 20% solution of phosgene in toluene are added dropwise at a reaction temperature of 5° to 10° C in the course of 13/4 hours to an emulsion of 56 g of 1-[2-hydroxy-3-(2-methoxyphenyloxy)-propyl]-4-[2-(4-chloroanilino)-ethylamino]-piperidine in 340 ml of toluene and 200 ml of a 3N potassium hydroxide solution. Thereafter 193 ml of a 6N aqueous potassium hydroxide solution are added dropwise at the same reaction temperature in the course of half an hour. The reaction mixture is further stirred for 1 hour at 5° to 10° C and for 20 hours at room temperature and then concentrated. The residue is made alkaline with a 2N aqueous sodium hydroxide solution and extracted with five 100 ml portions of methylene chloride. The extracts are dried over sodium sulphate and concentrated under reduced pressure. The residue is dissolved in methanol and boiled for 30 minutes with the addition of activated charcoal. The batch is filtered and the filtrate is concentrated under reduced pressure. The residue is treated with toluene and recrystallised from isopropanol to yield 1-{1-[2-hydroxy-3-(2-methoxyphenyloxy)-propyl]-4-piperidyl}-3-(4-chlorophenyl)-imidazolidin-2-one with a melting point of 136°-137° C.

Provenance & Evidence