Dicyclohexylcarbodiimide → N,N'-Dicyclohexylurea

HRID 846858Notes

Reaction equation

HRID 846858 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

Conditions

Temperature
0 °C

Procedure

ε-N-2ClZ-L-lysyl-L-prolyl-N-tosyl-L-arginyl-benzyl ester-2-thioamide (2 mmol) was dissolved in anhydrous DMF (0.5 ml) at 0° C. under N2 and α-N-Boc-threonine-O-benzyl ether (2 mmol) was added. HOBt (2 mmol) and DCC (2 mmol) were added portion-wise with stirring at 0° C. and the reaction was allowed to continue overnight. The reaction 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 chromatography on silica gel employing a 1:1 hexane-ethyl acetate solvent mixture as an eluant to afford α-N-Boc-L-threonyl-O-benzyl ether-ε-N-2ClZ-L-lysyl-L-prolyl-N-tosyl-L-arginyl-benzyl ester-3-thioamide in high yield.

Sources & evidence

ORD record
ord-0e5ebb5a4e1c47368c0d5de85cd0a5cd
Source dataset
uspto-grants-1992_08
Patent number
US05138061

Reaction notes

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