3-Hydroxyanthranilic Acid → 2-Phenylbenzoxazole-4-carboxylic acid

HRID 506215노트

반응식

HRID 506215 반응식
[OH:1][C:2]1[CH:10]=[CH:9][CH:8]=[C:4]([C:5]([OH:7])=[O:6])[C:3]=1[NH2:11].[C:12](Cl)(=O)[C:13]1[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=1.N1C=CC=CC=1.Cl.C1(C)C=CC(S(O)(=O)=O)=CC=1>C1(C)C=CC=CC=1.C(OCC)(=O)C.O>[C:13]1([C:12]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:18]=[CH:17][CH:16]=[CH:15][CH:14]=1

참가 물질

9

반응물 5

HCID 863-Hydroxyanthranilic AcidHCID 313Hydrochloric AcidHCID 1049PyridineHCID 6101p-Toluenesulfonic acidHCID 7412Benzoyl chloride

생성물 1

HCID 108683692-Phenylbenzoxazole-4-carboxylic acid수율 88%

시약·촉매·용매 3

HCID 962Water용매HCID 1140Toluene용매HCID 8857Ethyl Acetate용매2회

실험 절차

To a suspension of 3-hydroxyanthranilic acid (0.300 g, 1.96 mmol) in toluene (10 mL) was added benzoyl chloride (0.830 g, 5.90 mmol) followed by pyridine (0.545 g, 6.92 mmol) at room temperature. The resulting mixture was stirred at room temperature for 30 min 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 (50 mL). Subsequent separation of the layers, drying the organic over MgSO4 and filtration afforded an orange solution. This solution was concentrated to an orange solid which was directly re-dissolved in xylenes (20 mL) and the solution treated with p-toluenesulfonic acid (0.800 g, 4.20 mmol). The reaction mixture was then heated to reflux for 6 hrs. After this time the reaction was cooled and poured into water (50 mL), the organic layer separated then washed with water (3×50 mL). The organic was dried over MgSO4, filtered and concentrated to an orange/brown solid. Re-crystallization of this solid from ethyl acetate afforded 0.412 g (88% yield) of 2-phenylbenzoxazole-4-carboxylic acid as a light yellow solid: 1H NMR (300 MHz, CD3OD) δ 11.58 (br s, 1H), 8.30 (m, 2H), 8.17 (dd, J=7.8, 0.8 Hz, 1H), 7.83 (dd, J=8.2, 0.8 Hz, 1H), 7.69-7.45 (m, 4H); MS (APCI) m/z 240 [M+H]+.

후처리

  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 MgSO4 and filtration
  6. customafforded an orange solution
  7. concentrationThis solution was concentrated to an orange solid which
  8. dissolutionwas directly re-dissolved in xylenes (20 mL)
  9. temperatureThe reaction mixture was then heated
  10. temperatureto reflux for 6 hrs
  11. temperatureAfter this time the reaction was cooled
  12. customthe organic layer separated
  13. washthen washed with water (3×50 mL)
  14. dry with materialThe organic was dried over MgSO4
  15. filtrationfiltered
  16. concentrationconcentrated to an orange/brown solid

출처 및 근거

ORD 기록
ord-af56dc3c7a984f9e8a784467f448e326
출처 데이터셋
uspto-grants-2010_08
특허 번호
US07781430B2

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