Dicyclohexylcarbodiimide → HCID 13455629, compound
Reaction equation
O.[C:2]([O:6][C:7]([NH:9][C@H:10]([C:15]([OH:17])=O)[CH2:11][CH:12]([CH3:14])[CH3:13])=[O:8])([CH3:5])([CH3:4])[CH3:3].ON1C(=O)CCC1=O.C1(N=C=NC2CCCCC2)CCCCC1.[C:41]1([CH:47]([C:54]2[CH:59]=[CH:58][CH:57]=[CH:56][CH:55]=2)[N:48]2[CH2:53][CH2:52][NH:51][CH2:50][CH2:49]2)[CH:46]=[CH:45][CH:44]=[CH:43][CH:42]=1>C(Cl)Cl>[C:54]1([CH:47]([C:41]2[CH:46]=[CH:45][CH:44]=[CH:43][CH:42]=2)[N:48]2[CH2:49][CH2:50][N:51]([C:15]([C@@H:10]([NH:9][C:7](=[O:8])[O:6][C:2]([CH3:3])([CH3:4])[CH3:5])[CH2:11][CH:12]([CH3:13])[CH3:14])=[O:17])[CH2:52][CH2:53]2)[CH:55]=[CH:56][CH:57]=[CH:58][CH:59]=1Participants
Procedure
To a methylene chloride solution (100 ml) containing tert-butoxycarbonyl-L-leucine monohydrate (9.96 g) and N-hydroxy succinimide (4.6 g) was added dropwise a methylene chloride solution (50 ml) of N,N'-dicyclohexylcarbodiimide (8.24 g) with a length of time for 1 hour under cooling with ice. After being stirred at room temperature for 4 hours, the reaction mixture was again cooled with ice, and a methylene chloride solution (50 ml) of 1-(diphenylmethyl)piperazine (10.08 g) was added dropwise in 20 minutes. The mixture was stirred overnight at room temperature. Following the removal of the precipitate by filtration, the solvent was removed by distillation under reduced pressure, and ethyl acetate was added. After any insoluble matters were again removed by filtration, the filtrate was washed first with an aqueous sodium bicarbonate solution and then with a saturated sodium chloride solution, dried over magnesium sulfate and distilled under reduced pressure to remove the solvent, whereupon a crude reaction mixture was obtained. This reaction mixture was purified by silica gel column chromatography (developing solvent: chloroform followed by chloroform:methanol=50:1) to yield 16.5 g of tert-butyl (s)-1-(4-diphenylmethylpiperazine-1-yl carbonyl)-3-methylbutylcarbamate as a colorless amorphous substance (yield: 89%).
Workup
- temperatureunder cooling with ice
- temperaturethe reaction mixture was again cooled with ice
- stirringThe mixture was stirred overnight at room temperature
- customthe removal of the precipitate
- filtrationby filtration
- customthe solvent was removed by distillation under reduced pressure, and ethyl acetate
- additionwas added
- customAfter any insoluble matters were again removed by filtration
- washthe filtrate was washed first with an aqueous sodium bicarbonate solution
- dry with materialwith a saturated sodium chloride solution, dried over magnesium sulfate
- distillationdistilled under reduced pressure
- customto remove the solvent
- customwhereupon a crude reaction mixture
- customwas obtained
- customThis reaction mixture was purified by silica gel column chromatography (developing solvent: chloroform followed by chloroform:methanol=50:1)
Sources & evidence
- ORD record
- ord-d7026b958be849e38b9248ff09226625
- Source dataset
- uspto-grants-1986_06
- Patent number
- US04596803
Reaction notes
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