Dicyclohexylcarbodiimide → Benzyl 6-hydroxy-6-(4,4-dimethyl-2,6-dioxocyclohexylidene)-hexanoate

HRID 1368569Notes

Reaction equation

HRID 1368569 reaction equation
[C:1]([O:10][CH2:11][C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1)(=[O:9])[CH2:2][CH2:3][CH2:4][CH2:5][C:6]([O-:8])=O.[CH3:18][C:19]1([CH3:27])[CH2:24][C:23](=[O:25])[CH2:22][C:21](=[O:26])[CH2:20]1.C1(N=C=NC2CCCCC2)CCCCC1.CCOC(C)=O.CCCCCC>C(Cl)Cl.CN(C)C1C=CN=CC=1>[OH:8][C:6](=[C:22]1[C:23](=[O:25])[CH2:24][C:19]([CH3:27])([CH3:18])[CH2:20][C:21]1=[O:26])[CH2:5][CH2:4][CH2:3][CH2:2][C:1]([O:10][CH2:11][C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1)=[O:9]

Participants

7

Reactant 4

HCID 10868DicyclohexylcarbodiimideHCID 31358DimedoneHCID 19019622Benzyl adipateHCID 21226206Ethyl acetate hexane

Product 1

HCID 22728382Benzyl 6-hydroxy-6-(4,4-dimethyl-2,6-dioxocyclohexylidene)-hexanoateYield 84%

Reagents, catalysts & solvents 2

HCID 142844-(Dimethylamino)pyridineCatalystHCID 6344DichloromethaneSolvent

Procedure

To a stirred solution of mono-benzyl adipate (2.36g, 10 mmol) in dry CH2Cl2 (50 ml) was added 5,5-dimethyl-1,3-cyclohexanedione (1.4 g, 10 mmol), N,N′-dicyclohexylcarbodiimide (2.1 g, 10.1 mmol) and 4-dimethylaminopyridine (1.22 g, 10 mmol). The resulting solution was allowed to stir at room temperature for 18 h. The solution was cooled and filtered to remove the precipitated N,N′-dicyclohexylurea. The filtrate was evaporated and the residue redissolved in EtOAc (50 ml) and washed with 1 M KHSO4. The organic extract was washed with brine (92×10 ml), dried (MgSO4) and evaporated to yield a white/yellow amorphous powder. Flash silica chromatography (EtOAc/hexane 1:2 v/v) afforded benzyl 6-hydroxy-6-(4,4-dimethyl-2,6-dioxocyclohexylidene)-hexanoate (3.00 g, 84%) as a white crystalline solid. 1H NMR (CDCl3) δ 18.10 (s, 1H, OH), 7.30 (s, 5H, 5Ar—H), 5.06 (s, 2H, CH2Ar), 3.00 (t, 2H, CH2), 2.47 (s, 2H, Dde CH2), 2.35 (t, 2H, CH2CO2), 2.29 (s, 2H, Dde CH2), 1.65 (m, 4H, 2 CH2), 1.01 (s, 6H, 2 CH3); FAB MS C21H26O5 (358.18) m/z (%) 359 [M+H]+ (100), 267 (40); HRMS (FAB) Found: m/z 359.1858 Calcd for C21H27O5: (M+H), 359.1850.

Workup

  1. temperatureThe solution was cooled
  2. filtrationfiltered
  3. customto remove the precipitated N,N′-dicyclohexylurea
  4. customThe filtrate was evaporated
  5. dissolutionthe residue redissolved in EtOAc (50 ml)
  6. washwashed with 1 M KHSO4
  7. extractionThe organic extract
  8. washwas washed with brine (92×10 ml)
  9. dry with materialdried (MgSO4)
  10. customevaporated
  11. customto yield a white/yellow amorphous powder

Sources & evidence

ORD record
ord-333bbeb807f44ba48d214b4a9b01fd49
Source dataset
uspto-grants-2003_06
Patent number
US06573337B1

Reaction notes

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