3-Hydroxyanthranilic Acid → Acetate

HRID 415192Notes

Reaction equation

HRID 415192 reaction equation
[OH:1][C:2]1[CH:10]=[CH:9][CH:8]=[C:4]([C:5]([OH:7])=[O:6])[C:3]=1[NH2:11].[Cl:12][C:13]1[CH:21]=[CH:20][C:16]([C:17](Cl)=O)=[CH:15][CH:14]=1.N1C=CC=CC=1.Cl.CC1C=CC(S(O)(=O)=O)=CC=1>C1(C)C=CC=CC=1.O.C(OCC)(=O)C>[C:5]([O-:7])(=[O:6])[CH3:4].[Cl:12][C:13]1[CH:21]=[CH:20][C:16]([C:17]2[O:1][C:2]3[C:3](=[C:4]([C:5]([OH:7])=[O:6])[CH:8]=[CH:9][CH:10]=3)[N:11]=2)=[CH:15][CH:14]=1

Participants

10

Reactant 5

HCID 863-Hydroxyanthranilic AcidHCID 313Hydrochloric AcidHCID 1049PyridineHCID 6101p-Toluenesulfonic acidHCID 85014-Chlorobenzoyl chloride

Product 2

HCID 175AcetateHCID 596258542-(4-Chlorophenyl)benzoxazole-4-carboxylic acid

Reagents, catalysts & solvents 3

HCID 962WaterSolventHCID 1140TolueneSolventHCID 8857Ethyl AcetateSolvent

Procedure

To a suspension of 3-hydroxyanthranilic acid (0.153 g, 1.0 mmol) in toluene (10 mL) was added 4-chlorobenzoyl chloride (0.525 g, 3.0 mmol) followed by pyridine (0.275 g, 3.5 mmol) at room temperature. The resulting mixture was stirred at room temperature for 30 minutes then heated to 80° C. for 1 hr. After this time the reaction was cooled and poured into a mixture of ethyl acetate (50 mL) and 5% aqueous hydrochloric acid (20 mL). Subsequent separation of the layers, drying the organic over anhydrous magnesium sulfate and filtration afforded a solution. After removal of the solvent, the residue was dissolved in toluene (20 mL) and the solution treated with 4-methylbenzenesulfonic acid (0.4 g, 2.1 mmol). The reaction mixture was then heated to reflux overnight. After this time the reaction was cooled and poured into water (100 mL), the organic layer separated then washed with water (100 mL). The organic was dried over anhydrous magnesium sulfate, filtered and concentrated to a solid. Re-crystallization of this solid from acetate gave 2-(4-chlorophenyl)benzo[d]oxazole-4-carboxylic acid as a white solid product (0.068 g, 24.9% yield). MS (ESI) m/z 274 [M+1]+.

Workup

  1. temperaturethen heated to 80° C. for 1 hr
  2. temperatureAfter this time the reaction was cooled
  3. customSubsequent separation of the layers
  4. customdrying the
  5. filtrationorganic over anhydrous magnesium sulfate and filtration
  6. customafforded a solution
  7. customAfter removal of the solvent
  8. dissolutionthe residue was dissolved in toluene (20 mL)
  9. temperatureThe reaction mixture was then heated
  10. temperatureto reflux overnight
  11. temperatureAfter this time the reaction was cooled
  12. customthe organic layer separated
  13. washthen washed with water (100 mL)
  14. dry with materialThe organic was dried over anhydrous magnesium sulfate
  15. filtrationfiltered
  16. concentrationconcentrated to a solid

Sources & evidence

ORD record
ord-34752b288173461ba4102232789121aa
Source dataset
uspto-grants-2012_01
Patent number
US08088760B2

Reaction notes

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