1,1'-Carbonyldiimidazole → Hydrochloric Acid

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Reaction Steps

1.3 g of ethylmercaptoacetic acid are dissolved in 25 ml of N,N-dimethylformamide, and 2.3 g of N,N-carbonyldiimidazole are added. After 15 minutes at RT, the mixture is heated for 5 minutes at 90° ET. Then 3.5 g of 1-[4-(N-methylamino)benzoyl]-4-[2-(4-chlorophenyl)ethyl]piperazine (see European Patent Application No. 489 690, Example 9) are added thereto, and the reaction mixture is kept at 110° ET for 14 hours. The mixture is concentrated by evaporation and the oil is chromatographed over silica gel (eluant: dichloromethane/acetone 8:2). Treatment with alcoholic hydrochloric acid yields 1-{4-[N-methyl-N-ethylmercaptoacetylamino]benzoyl}-4-[2-(4-chlorophenyl)ethyl]piperazine hydrochloride having a melting point of 163°-164°.

Provenance & Evidence