تفاعل #1148

معادلة التفاعل

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

المردود 60.0%

المذيبات

tetrahydrofuran

N,N-dimethylformamide

ظروف التفاعل

المعالجة

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

الإجراء التجريبي

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.

المصدر