Acetic Acid → N,N'-Dicyclohexylurea

HRID 597485Notes

Reaction equation

HRID 597485 reaction equation
[OH:1][C@@H]1CN2C(=O)[C@@H](NC(=O)CC3C=CC=CC=3)[C@H]2SC1.[CH:21]1([N:27]=[C:28]=[N:29][CH:30]2[CH2:35][CH2:34][CH2:33][CH2:32][CH2:31]2)[CH2:26][CH2:25][CH2:24][CH2:23][CH2:22]1.FC(F)(F)C(O)=O.N1C=CC=CC=1.C(O)(=O)C>CS(C)=O.C(OCC)(=O)C.O>[C:28]([NH:27][CH:21]1[CH2:22][CH2:23][CH2:24][CH2:25][CH2:26]1)([NH:29][CH:30]1[CH2:35][CH2:34][CH2:33][CH2:32][CH2:31]1)=[O:1]

Participants

8

Reactant 4

HCID 176Acetic AcidHCID 10868DicyclohexylcarbodiimideHCID 309472Pyridinium trifluoroacetateHCID 54466737HCID 54466737, compound

Product 1

HCID 4277N,N'-DicyclohexylureaYield 218.3%

Reagents, catalysts & solvents 3

HCID 679Dimethyl SulfoxideSolventHCID 962WaterSolventHCID 8857Ethyl AcetateSolvent

Procedure

A solution of (3R,6R,7R)-3-hydroxy-7-phenylacetamido cepham (6.0 g., 20.5 mmole) and dicyclohexylcarbodiimide (11.65 g., 56.6 mmole) in dimethyl sulphoxide (50 ml.) was treated with pyridine trifluoroacetate (1.37 g., 7.1 mmole) and the mixture was stirred at 26° for 11/2 hours. Acetic acid (6 ml.) and water (2 ml.) were added and the mixture was stirred for 30 minutes before being diluted with ethyl acetate (250 ml.) and filtered to give dicylohexylurea (10.04 g., 79%) as colourless prisms. The filtrate was washed with saturated aqueous sodium hydrogen carbonate (2 × 200 ml.), dried, and evaporated under reduced pressure to give a brown solid (7.65 g.). The solid was refluxed with acetonitrile (100 ml.) for 5 minutes, filtered to give more dicyclohexyl urea (0.4 g., 3.2%) and the filtrate was evaporated under reduced pressure. The resulting brown solid was dissolved by heating under reflux with isopropyl alcohol (150 ml.) for 15 minutes and on cooling, crystals of (6R,7R)-3-keto-7-phenylacetamidocepham (3.6 g., 60.5% in two crops) separated out; m.p. and NMR were in agreement with standards.

Workup

  1. stirringthe mixture was stirred for 30 minutes
  2. filtrationfiltered

Sources & evidence

ORD record
ord-945e1af6fad2444da0802283dcf5b5a4
Source dataset
uspto-grants-1977_03
Patent number
US04014872

Reaction notes

Loading…