반응 #6524

반응 방정식

sodium acetate

5-(pyrrol-2-yl)oxazole

dimethylformamide

phosphorus oxychloride

→

5-(5-formylpyrrol-2-yl)oxazole

수율 80.0%

용매

chloroform

1,2-dichloroethane

반응 조건

후처리

1. 1
   workup.STIRRINGThe mixture was stirred 20 minutes
2. 2
   온도while cooling in an ice bath
3. 3
   온도The reaction mixture was then heated
4. 4
   온도under reflux for 20 minutes
5. 5
   온도After heating
6. 6
   온도under reflux for 20 minutes
7. 7
   온도the mixture was cooled to room temperature
8. 8
   기타the organic layer separated
9. 9
   세척washed with aqueous sodium carbonate
10. 10
    건조dried over anhydrous sodium sulfate
11. 11
    기타evaporation of the solvent at reduced pressure
12. 12
    기타the crude product was purified by column chromatography with chloroform elution

실험 절차

To an ice cooled 1 mL dimethylformamide was added 0.82 g (5.4 mmol) of phosphorus oxychloride while stirring under a nitrogen atmosphere. The mixture was stirred 20 minutes and then was added a solution of 0.60 g (4.5 mmol) of 5-(pyrrol-2-yl)oxazole in 15 mL of 1,2-dichloroethane while cooling in an ice bath. The reaction mixture was then heated under reflux for 20 minutes. After cooling to room temperature, 50 mL of chloroform was added followed by 60 mL of saturated aqueous sodium acetate. After heating under reflux for 20 minutes, the mixture was cooled to room temperature and the organic layer separated, washed with aqueous sodium carbonate and dried over anhydrous sodium sulfate. Following evaporation of the solvent at reduced pressure, the crude product was purified by column chromatography with chloroform elution to give 0.58 g (80%) of 5-(5-formylpyrrol-2-yl)oxazole as a white solid, m.p. 152°-153° C.; 1H-NMR (Acetone-d6) δ 6.68 (d, 1H, ArH), 7.09 (d, 1H, ArH), 7.61 (S, 1H, ArH), 8,22 (s, 1H, ArH), 9.57 (s, 1H, CHO).

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