Dicyclohexylcarbodiimide → N,N'-Dicyclohexylurea

HRID 65432Notes

Reaction equation

HRID 65432 reaction equation
N12CCCCC1C=NCCC2.Br[C@@H](CO)C(O)=[O:15].[CH:19]1([N:25]=[C:26]=[N:27][CH:28]2[CH2:33][CH2:32][CH2:31][CH2:30][CH2:29]2)[CH2:24][CH2:23][CH2:22][CH2:21][CH2:20]1.[Cl-].C([NH2+]CSC(C)(C)C)C1C=CC=CC=1>O1CCCC1>[C:26]([NH:25][CH:19]1[CH2:20][CH2:21][CH2:22][CH2:23][CH2:24]1)([NH:27][CH:28]1[CH2:33][CH2:32][CH2:31][CH2:30][CH2:29]1)=[O:15]

Participants

6

Reactant 4

HCID 10868DicyclohexylcarbodiimideHCID 3141121,5-Diazabicyclo(5,4,0)undec-5-eneHCID 13776210(2S)-2-Bromo-3-hydroxypropanoic acidHCID 86741047N-benzyl-N-tert.-butylthiomethylammonium chloride

Product 1

HCID 4277N,N'-Dicyclohexylurea

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

5 ml of a 2M solution of 1,5-diazabicyclo[5.4.0]-undec-5-ene (DBU) in tetrahydrofuran are added while stirring, at room temperature, to a solution of 845 mg (5 mmol) of 2-(S)-bromo-3-hydroxypropionic acid in 10 ml of absolute tetrahydrofuran and the resulting mixture is stirred for a further 2 hours at room temperature. The solvent is subsequently distilled off in vacuo and 25 ml of methylene chloride are added. To this solution containing the DBU salt of (R)-glycidic acid there are added 1.03 g (5 mmol) of dicyclohexyl carbodiimide and, after stirring for one hour, 1.3 g (5 mmol) of N-benzyl-N-tert.-butylthiomethylammonium chloride. After the addition of the last-mentioned reaction component, crystalline dicyclohexylurea is formed. After a reaction time of 3 hours at room temperature, the latter is filtered off with suction and the filtrate is diluted with methylene chloride and washed with phosphate buffer solution having a pH of 8. After concentration of the organic phase by evaporation, the residue is chromatographed over 50 g of silica gel. After a few first fractions have been removed with toluene, the title compound is eluted with a mixture of toluene/ethyl acetate (9:1) in the form of a colourless, viscous oil.

Workup

  1. distillationThe solvent is subsequently distilled off in vacuo and 25 ml of methylene chloride
  2. additionare added
  3. additionTo this solution containing the DBU salt of (R)-glycidic acid
  4. stirringafter stirring for one hour
  5. additionAfter the addition of the last-mentioned reaction component

Sources & evidence

ORD record
ord-49749a1f70e84499b6a50f4755765397
Source dataset
uspto-grants-1986_09
Patent number
US04614614

Reaction notes

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