Methanesulfonic Acid → 5-Chloro-2-(2-fluoronitrobenzen-5-yl)benzoxazole

HRID 74282

Reaction equation

HRID 74282 reaction equation
[F:1][C:2]1[CH:10]=[CH:9][C:5]([C:6]([OH:8])=O)=[CH:4][C:3]=1[N+:11]([O-:13])=[O:12].[NH2:14][C:15]1[CH:20]=[C:19]([Cl:21])[CH:18]=[CH:17][C:16]=1O.CCN=C=NCCCN(C)C.CS(O)(=O)=O>O.C(Cl)(Cl)Cl>[Cl:21][C:19]1[CH:18]=[CH:17][C:16]2[O:8][C:6]([C:5]3[CH:9]=[CH:10][C:2]([F:1])=[C:3]([N+:11]([O-:13])=[O:12])[CH:4]=3)=[N:14][C:15]=2[CH:20]=1

Participants

7

Reactant 4

HCID 6395Methanesulfonic AcidHCID 72652-Amino-4-chlorophenolHCID 159081-Ethyl-3-(3'-dimethylaminopropyl)carbodiimideHCID 679874-Fluoro-3-nitrobenzoic acid

Product 1

HCID 674975535-Chloro-2-(2-fluoronitrobenzen-5-yl)benzoxazoleYield 78.5%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6212ChloroformSolvent

Procedure

4-Fluoro-3-nitrobenzoic acid (25.0 g, 135 mmol), 2-amino-4-chlorophenol (21.3 g, 149 mmol), CHCl3 (500 mL), and WSC (28.5 g, 149 mmol) were added together and stirred at room temperature for 2 hours. The reaction mass was concentrated, and then the residue was washed with water and ethanol. To a dioxane (500 mL) solution of the solid obtained was added methanesulfonic acid (81.9 g, 811 mmol), and this was heated to reflux for 18 hours. After the reaction solution was cooled, water was added, and the precipitated crystals were filtered, and after being washed with water were dried to yield the title compound (31.0 g, 78% yield) as reddish-brown crystals.

Workup

  1. concentrationThe reaction mass was concentrated
  2. washthe residue was washed with water and ethanol
  3. customTo a dioxane (500 mL) solution of the solid obtained
  4. temperaturethis was heated
  5. temperatureto reflux for 18 hours
  6. temperatureAfter the reaction solution was cooled
  7. filtrationthe precipitated crystals were filtered
  8. washafter being washed with water
  9. customwere dried

Sources & evidence

ORD record
ord-618b7835bd0d45cfad28533ecc641084
Source dataset
uspto-grants-2014_09
Patent number
US08829035B2

Linked notes

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