Dimethylformamide → 2-(4-Hexyloxyphenyl)-5-ethoxycarbonylbenzoxazole

HRID 1872405Notes

Reaction equation

HRID 1872405 reaction equation
[CH2:1]([O:7][C:8]1[CH:16]=[CH:15][C:11]([C:12](O)=O)=[CH:10][CH:9]=1)[CH2:2][CH2:3][CH2:4][CH2:5][CH3:6].CN(C)C=O.[NH2:22][C:23]1[CH:24]=[C:25]([CH:31]=[CH:32][C:33]=1[OH:34])[C:26]([O:28][CH2:29][CH3:30])=[O:27].C(OC1C=CC(C(Cl)=O)=CC=1)CCCCC>C(Cl)(=O)C(Cl)=O.ClCCl.CN(C)C1C=CN=CC=1.C(N(CC)CC)C>[CH2:1]([O:7][C:8]1[CH:16]=[CH:15][C:11]([C:12]2[O:34][C:33]3[CH:32]=[CH:31][C:25]([C:26]([O:28][CH2:29][CH3:30])=[O:27])=[CH:24][C:23]=3[N:22]=2)=[CH:10][CH:9]=1)[CH2:2][CH2:3][CH2:4][CH2:5][CH3:6]

Participants

9

Reactant 4

HCID 6228DimethylformamideHCID 708344-(Hexyloxy)benzoic acidHCID 170235Benzoyl chloride, 4-(hexyloxy)-HCID 12208891Ethyl 3-amino-4-hydroxybenzoate

Product 1

HCID 211824882-(4-Hexyloxyphenyl)-5-ethoxycarbonylbenzoxazole

Reagents, catalysts & solvents 4

HCID 142844-(Dimethylamino)pyridineCatalystHCID 6344DichloromethaneSolvent4×HCID 8471TriethylamineSolventHCID 65578Oxalyl chlorideSolvent

Procedure

To a suspension of 4-hexyloxybenzoic acid in oxalyl chloride (10 ml) and dichloromethane (10 ml) was added N,N-dimethylformamide (0.1 ml). The mixture was stirred at room temperature for 2 hours. The solvent was removed under reduced pressure to give crude 4-hexyloxybenzoyl chloride. To a suspension of Ethyl 3-amino-4-hydroxybenzoate (733 mg) and triethylamine (1.38 ml) and 4-dimethylaminopyridine (DMAP, 10 mg) in methylene chloride (10 ml) was added the solution of 4-hexyloxybenzoyl chloride obtained above in dichloromethane (5 ml) dropwise at 10° C. The reaction mixture was stirred at 10° C. for 1.5 hours and diluted with dichloromethane (20 ml). The solution was washed with H2O (20 ml), 1 N HCl aq. (20 ml×2), H2O (20 ml) and brine (20 ml) successively. The organic layer was dried over MgSO4 and the solvent was removed under reduced pressure. To the residue was added toluene (15 ml) and p-toluenesulfonic acid (10 mg). The mixture was refluxed for 6 hours and the solvent was removed under reduced pressure. The residue was triturated with acetonitrile, and precipitate was collected with filtration and dried over PO5 to give 2-(4-Hexyloxyphenyl)-5-ethoxycarbonylbenzoxazole (0.60 g).

Workup

  1. customThe solvent was removed under reduced pressure
  2. customto give crude 4-hexyloxybenzoyl chloride
  3. stirringThe reaction mixture was stirred at 10° C. for 1.5 hours
  4. washThe solution was washed with H2O (20 ml), 1 N HCl aq. (20 ml×2), H2O (20 ml) and brine (20 ml) successively
  5. dry with materialThe organic layer was dried over MgSO4
  6. customthe solvent was removed under reduced pressure
  7. additionTo the residue was added toluene (15 ml) and p-toluenesulfonic acid (10 mg)
  8. temperatureThe mixture was refluxed for 6 hours
  9. customthe solvent was removed under reduced pressure
  10. customThe residue was triturated with acetonitrile, and precipitate
  11. filtrationwas collected with filtration
  12. customdried over PO5

Sources & evidence

ORD record
ord-63a8de7594c54c63950d64fa47bad2b0
Source dataset
uspto-grants-2000_08
Patent number
US06107458

Reaction notes

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