Dicyclohexylcarbodiimide → N,N'-Dicyclohexylurea

HRID 846854Notes

Reaction equation

HRID 846854 reaction equation
C1C=CC2N([OH:10])N=NC=2C=1.[CH2:11]1[CH2:16][CH2:15][CH:14]([N:17]=[C:18]=[N:19][CH:20]2[CH2:25][CH2:24][CH2:23][CH2:22][CH2:21]2)[CH2:13][CH2:12]1>CN(C=O)C.C(OCC)(=O)C>[CH:20]1([NH:19][C:18]([NH:17][CH:14]2[CH2:13][CH2:12][CH2:11][CH2:16][CH2:15]2)=[O:10])[CH2:25][CH2:24][CH2:23][CH2:22][CH2:21]1

Participants

5

Reactant 2

HCID 10868DicyclohexylcarbodiimideHCID 757711-Hydroxybenzotriazole

Product 1

HCID 4277N,N'-Dicyclohexylurea

Reagents, catalysts & solvents 2

HCID 6228DimethylformamideSolventHCID 8857Ethyl AcetateSolvent

Procedure

L-valyl-L-tyrosyl-O-benzyl-thioamide (2 mmol) was dissolved in anhydrous DMF (0.5 ml) at 0° C. under N2 and α-N-Boc-L-aspartyl-β-benzyl ester (2 mmol) was added to the solution with stirring. HOBt (2 mmol) and DCC (2 mmol) were added slowly at 0° C. and stirring was allowed to continue overnight. The mixture was diluted with 8 volumes of ethyl acetate and the N,N'-dicyclohexylurea so formed was filtered away from the solution. The filtrate was transferred to a separatory funnel and washed successively with 5% aqueous sodium bicarbonate, 5% aqueous citric acid, and saturated brine. The organic phase was collected and dried over MgSO4, filtered and concentrated in vacuo. The residue was purified by flash chromotography on silica gel employing a 1:1 hexane-ethyl acetate solvent mixture as an eluant to afford the α-N-Boo-L-aspartyl-β-benzyl ester-L-valyl-L-tyrosyl-O-benzyl ether-benzyl ester-3-thioamide in good yield (74%). The following physical characteristics were recorded for the compound: Melting point 112°-114° C. and UV (CHCl3) lambdamax 271.

Workup

  1. stirringstirring

Sources & evidence

ORD record
ord-7210a5adeab640fd8db40bda58767c2a
Source dataset
uspto-grants-1992_08
Patent number
US05138061

Reaction notes

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