반응 #1148

반응 방정식

Sodium hydride

3-cyanopropyltriphenylphosphonium bromide

hydrochloric acid

6-(5-Methyl-2-phenyl-4-oxazolylmethoxy)benzofuran-2-carboaldehyde

→

2-(4-cyanobutyl)-6-(5-methyl-2-phenyl-4-oxazolylmethoxy)benzofuran

수율 60.0%

용매

tetrahydrofuran

N,N-dimethylformamide

반응 조건

후처리

1. 1
   workup.STIRRINGby stirring at 70° to 80° C. for 2 hours
2. 2
   추출followed by extraction with ethyl acetate (200 ml)
3. 3
   세척After the ethyl acetate layer was washed with water
4. 4
   건조dried (MgSO4)
5. 5
   workup.DISTILLATIONthe solvent was distilled off
6. 6
   세척From the fraction eluted with ethyl acetate-hexane (1:2
7. 7
   기타v/v), an oily substance was obtained
8. 8
   기타followed by catalytic reduction at room temperature and under an atmospheric pressure of 1 atm
9. 9
   여과The catalyst was filtered off
10. 10
    농축the filtrate was concentrated
11. 11
    세척From the fraction eluted with ethyl acetate-hexane (1:3

실험 절차

Sodium hydride (60%, oily, 0.20 g) was gradually added to a solution of 3-cyanopropyltriphenylphosphonium bromide (2.07 g) in N,N-dimethylformamide (30 ml) at room temperature, followed by stirring for 1 hour. 6-(5-Methyl-2-phenyl-4-oxazolylmethoxy)benzofuran-2-carboaldehyde (1.40 g) was added, followed by stirring at 70° to 80° C. for 2 hours. The reaction mixture was poured over ice water and neutralized with 2N hydrochloric acid, followed by extraction with ethyl acetate (200 ml). After the ethyl acetate layer was washed with water and dried (MgSO4), the solvent was distilled off; the residue was subjected to silica gel column chromatography. From the fraction eluted with ethyl acetate-hexane (1:2, v/v), an oily substance was obtained, which was dissolved in tetrahydrofuran (40 ml). To this solution, palladium-carbon (5%, 0.70 g) was added, followed by catalytic reduction at room temperature and under an atmospheric pressure of 1 atm. The catalyst was filtered off, the filtrate was concentrated; the residue was subjected to silica gel column chromatography. From the fraction eluted with ethyl acetate-hexane (1:3, v/v), crystals of 2-(4-cyanobutyl)-6-(5-methyl-2-phenyl-4-oxazolylmethoxy)benzofuran (0.97 g, 60%) were obtained, which was then recrystallized from diethyl ether-hexane to yield colorless prisms having a melting point of 87° to 88° C.

출처