Dichloromethane → Piperidine, 1,1'-carbonyldi-

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Reaction Steps

Phosgene was passed for 17 minutes, at the rate of 3 grams per minute, through a mixture of 84 grams (1 mole) of piperidine, 500 ml. of methylene chloride and 100 ml. of water. The pH was maintained in the range of 8-11 by the addition of 50% aqueous sodium hydroxide solution during the latter portion of the phosgene passage. An exothermic reaction occurred which caused refluxing of the mixture. After phosgenation was complete, additional base was added until the pH remained constant at 11 for 5 minutes, after which 200 ml. of water was added and the organic layer was removed, washed twice with aqueous hydrochloric acid solution and filtered. Upon vacuum stripping, the desired bis(pentamethylene)urea was obtained in 96% yield. Its structure was confirmed by proton nuclear magnetic resonance spectroscopy.

Provenance & Evidence