Phosgene → Butyl piperazine-1-carboxylate hydrochloride
Reaction equation
[CH2:1]([O:5][C:6]([N:8]1[CH2:13][CH2:12][NH:11][CH2:10][CH2:9]1)=[O:7])[CH2:2][CH2:3][CH3:4].C(Cl)([Cl:16])=O>C1(C)C=CC=CC=1>[ClH:16].[CH2:1]([O:5][C:6]([N:8]1[CH2:13][CH2:12][NH:11][CH2:10][CH2:9]1)=[O:7])[CH2:2][CH2:3][CH3:4]Participants
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 2 °C
Procedure
4-Chlorocarbonyl-1-t.-butoxycarbonylpiperazine can be prepared by the simultaneous additions of solutions of 1-t.-butoxycarbonylpiperazine (40.8 g.) in anhydrous toluene (200 cc.) and of phosgene (11.2 g.) in anhydrous toluene (150 cc.) to anhydrous toluene (100 cc.), the temperature being kept at about -5° C. during this operation. After stirring for 1 hour at 2° C., the 1-t.-butoxycarbonylpiperazine hydrochloride formed during the reaction is filtered off and washed twice with anhydrous toluene (total 200 cc.). The filtrate is evaporated to dryness under reduced pressure (20 mm.Hg.). 4-Chlorocarbonyl-1-t.-butoxycarbonylpiperazine (24.8 g.), which melts at 98° C., is obtained. After the product has been purified by recrystallisation from diisopropyl ether, it melts at 99° C.
Workup
- custombeing kept at about -5° C. during this operation
Sources & evidence
- ORD record
- ord-f31cc9f138824e28b8bca627ea694832
- Source dataset
- uspto-grants-1980_09
- Patent number
- US04220646
Reaction notes
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