ethyl N-piperazin-1-ylcarbamate

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 17.0 g of 1-benzoyl-4-bromobutane, 13.4 g of 1-(ethoxycarbonylamino)piperazine and 17.8 g of sodium hydrogen carbonate were heated under reflux in ethanol for 6 hours with stirring. The insoluble materials were removed from the reaction mixture by filtration. The solvent was distilled off, and water was added to the residue. The mixture was extracted with benzene. The extract was recrystallized from benzene-hexane to give 21.4 g of 4-(4-benzoylbutyl)-1-(ethoxycarbonylamino)-piperazine having a melting point of 105° to 106° C. The insoluble materials were removed from the reaction mixture by filtration The solvent was distilled off water was added to the residue The mixture was extracted with benzene The extract was recrystallized from benzene-hexane

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 17.0 g of 1-benzoyl-4-bromobutane, 13.4 g of 1-(ethoxycarbonylamino)piperazine and 17.8 g of sodium hydrogen carbonate were heated under reflux in ethanol for 6 hours with stirring. The insoluble materials were removed from the reaction mixture by filtration. The solvent was distilled off, and water was added to the residue. The mixture was extracted with benzene. The extract was recrystallized from benzene-hexane to give 21.4 g of 4-(4-benzoylbutyl)-1-(ethoxycarbonylamino)-piperazine having a melting point of 105° to 106° C. The insoluble materials were removed from the reaction mixture by filtration The solvent was distilled off water was added to the residue The mixture was extracted with benzene The extract was recrystallized from benzene-hexane

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 29.2 g of 5-bromovalerophenone and 23 g of 1-(ethoxycarbonylamino)piperazine were dissolved in 250 ml of ethanol. 30.5 g of sodium hydrogen carbonate was added, and the mixture was heated under reflux for 6 hours. Ethanol was evaporated from the reaction mixture. After addition of water, the residue was extracted with benzene. The extract was recrystallized from benzene-hexane to give 36.2 g of the title compound having a melting point of 105° to 106° C. the mixture was heated under reflux for 6 hours Ethanol was evaporated from the reaction mixture After addition of water the residue was extracted with benzene The extract was recrystallized from benzene-hexane

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 17.0 g of 1-benzoyl-4-bromobutane, 13.4 g of 1-(ethoxycarbonylamino)piperazine and 17.8 g of sodium hydrogen carbonate were heated under reflux in ethanol for 6 hours with stirring. The insoluble materials were removed from the reaction mixture by filtration. The solvent was distilled off, and water was added to the residue. The mixture was extracted with benzene. The extract was recrystallized from benzene-hexane to give 21.4 g of 4-(4-benzoylbutyl)-1-(ethoxycarbonylamino)-piperazine having a melting point of 105° to 106° C. The insoluble materials were removed from the reaction mixture by filtration The solvent was distilled off water was added to the residue The mixture was extracted with benzene The extract was recrystallized from benzene-hexane