Phenylacetyl chloride → 2-Benzylbenzoxazole-4-carboxylic acid

HRID 2059680Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 2059680
Br.[NH2:2][C:3]1[C:11]([OH:12])=[CH:10][CH:9]=[CH:8][C:4]=1[C:5]([OH:7])=[O:6].C(N(CC)CC)C.[C:20]1([CH2:26][C:27](Cl)=O)[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=1.O.C1(C)C=CC(S(O)(=O)=O)=CC=1>ClCCl.O>[CH2:26]([C:27]1[O:12][C:11]2[C:3](=[C:4]([C:5]([OH:7])=[O:6])[CH:8]=[CH:9][CH:10]=2)[N:2]=1)[C:20]1[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=1

Komponenten

7

Edukt 4

HCID 7679Phenylacetyl chlorideHCID 8471TriethylamineHCID 521998p-Toluenesulfonic acid monohydrateHCID 668807402-Amino-3-hydroxybenzoic acid hydrobromide

Produkt 1

HCID 689956662-Benzylbenzoxazole-4-carboxylic acidAusbeute 51,1 %

Reagenzien, Katalysatoren, Lösungsmittel 2

HCID 962WaterLösungsmittelHCID 6344DichloromethaneLösungsmittel2×

Versuchsvorschrift

To a mixture of 2-amino-3-hydroxybenzoic acid hydrobromide (0.5 g, 2.14 mmol) and triethylamine (0.90 mL, 6.42 mmol) in dichloromethane (15 mL) was added phenylacetyl chloride (0.28 mL, 2.14 mmol) dropwise, then the reaction mixture was stirred at room temperature overnight. The reaction mixture was diluted with dichloromethane, and then washed with 2 N HCl. The aqueous layer was extracted with dichloromethane. The combined organic layers were washed with brine, dried (Na2SO4), filtered and concentrated. The crude product was dissolved in toluene (8 mL) and the solution was treated with p-toluenesulfonic acid monohydrate (537 mg, 2.83 mmol). The reaction mixture was then heated to reflux for 5 h. The reaction was cooled to room temperature, poured into water and extracted with ethyl acetate. The organic layer was separated, then washed with water (3×100 mL), brine, dried (Na2SO4), filtered and concentrated to afford 2-benzylbenzoxazole-4-carboxylic acid (277 mg, 51%) as a white solid: 1H NMR (500 MHz, DMSO-d6) δ 13.08 (br s, 1H), 7.91 (dd, J=7.1, 1.0 Hz, 1H), 7.85 (dd, J=7.7, 1.0 Hz, 1H), 7.44 (t, J=7.9 Hz, 1H), 7.40-7.34 (m, 4H), 7.31-7.27 (m, 1H), 4.40 (s, 2H); MS (ESI+) m/z 254 (M+H).

Aufarbeitung

  1. washwashed with 2 N HCl
  2. extractionThe aqueous layer was extracted with dichloromethane
  3. washThe combined organic layers were washed with brine
  4. dry with materialdried (Na2SO4)
  5. filtrationfiltered
  6. concentrationconcentrated
  7. dissolutionThe crude product was dissolved in toluene (8 mL)
  8. temperatureThe reaction mixture was then heated
  9. temperatureto reflux for 5 h
  10. temperatureThe reaction was cooled to room temperature
  11. extractionextracted with ethyl acetate
  12. customThe organic layer was separated
  13. washwashed with water (3×100 mL), brine
  14. dry with materialdried (Na2SO4)
  15. filtrationfiltered
  16. concentrationconcentrated

Quellen und Nachweise

ORD-Eintrag
ord-ce31240e201e44efa00b9e4ae9fb2b46
Quelldatensatz
uspto-grants-2012_10
Patentnummer
US08278301B2

Notizen zur Reaktion

Wird geladen…