反应 #1148

反应方程式

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

收率 60.0%

溶剂

tetrahydrofuran

N,N-dimethylformamide

反应条件

后处理

1. 1
   workup.STIRRINGby stirring at 70° to 80° C. for 2 hours
2. 2
   萃取followed by extraction with ethyl acetate (200 ml)
3. 3
   洗涤After the ethyl acetate layer was washed with water
4. 4
   干燥dried (MgSO4)
5. 5
   workup.DISTILLATIONthe solvent was distilled off
6. 6
   洗涤From the fraction eluted with ethyl acetate-hexane (1:2
7. 7
   其他v/v), an oily substance was obtained
8. 8
   其他followed by catalytic reduction at room temperature and under an atmospheric pressure of 1 atm
9. 9
   过滤The catalyst was filtered off
10. 10
    浓缩the filtrate was concentrated
11. 11
    洗涤From the fraction eluted with ethyl acetate-hexane (1:3

实验过程

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.

来源