1-Piperazinecarboxylic acid, ethyl ester → HCID 54134626, compound
Reaction equation
[CH3:1][S:2][C:3]1[CH:8]=[CH:7][C:6]([CH2:9][CH2:10]Cl)=[CH:5][CH:4]=1.[CH2:12]([O:14][C:15]([N:17]1[CH2:22][CH2:21][NH:20][CH2:19][CH2:18]1)=[O:16])[CH3:13].[OH-].[Na+]>>[CH3:1][S:2][C:3]1[CH:8]=[CH:7][C:6]([CH2:9][CH2:10][N:20]2[CH2:19][CH2:18][N:17]([C:15]([O:14][CH2:12][CH3:13])=[O:16])[CH2:22][CH2:21]2)=[CH:5][CH:4]=1Participants
Procedure
Under nitrogen, 59.6 g of 4-methylmercaptophenylethyl chloride are heated with 75.7 g of 1-ethoxycarbonylpiperazine for 1.5 hours at 130°. A further 25.2 g of 1-ethoxycarbonylpiperazine are added thereto, and after 1.5 hours a further 25.2 g of 1-ethoxycarbonylpiperazine are added. After a total of 4.5 hours, the solution is poured onto ice-water, rendered strongly alkaline with concentrated NaOH and extracted with ether. Concentration by evaporation yields a mobile oil, which is purified by chromatography over silica gel (eluant: dichloromethane and dichloromethane/acetone 8:2). 90 g of the 1-[(4-methylmercaptophenyl)ethyl]-4-ethoxycarbonylpiperazine so obtained are boiled under reflux for 17 hours with 700 ml of concentrated HCl. The solution is diluted with ice-water, rendered alkaline with concentrated NaOH, extracted with ethyl acetate, concentrated by evaporation and recrystallised from ether/petroleum ether. The 1-[2-(4-methylmercaptophenyl)ethyl]piperazine melts at 52°-54°.
Workup
- additionAfter a total of 4.5 hours, the solution is poured onto ice-water
- extractionextracted with ether
- concentrationConcentration
- customby evaporation
- customyields a mobile oil, which
- customis purified by chromatography over silica gel (eluant: dichloromethane and dichloromethane/acetone 8:2)
Sources & evidence
- ORD record
- ord-06c87d20cee844c7a70b0c0af371c8a2
- Source dataset
- uspto-grants-1994_02
- Patent number
- US05286728
Reaction notes
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