反应详情

Tetrabutylammonium chloride (hydrate, 17.8 g) was dried by azeotroping with benzene (250 mL round bottom flask equipped with a Dean-Stark apparatus). The benzene was removed in vacuo affording anhydrous tetrabutylammonium chloride (17.0 g, 61.2 mmol). To this flask under argon were added triphenylphosphine (820 mg, 3.13 mmol), palladium acetate (703 mg, 3.13 mmol), 4-bromobenzonitrile (16.9 g, 92.8 mmol), potassium acetate (36.8g, 375 mmol) and 100 mL of degassed anhydrous dimethylformamide (degassed by bubbling argon through for 10 min, dried over molecular sieves). A solution of 4-pentenoic acid (6.27 g, 62.6 mmol) and degassed anhydrous DMF (35 mL) was then added to the rapidly stirring reaction mixture at 23° C. After 21 hours at 23° C., the reaction mixture was poured slowly into a sodium carbonate solution (3%, 400 mL) and extracted with ethyl acetate (500 mL). The aqueous layer was treated with decolorizing carbon and filtered. Then, the aqueous layer was acidified to a pH of 2 with 10% HCl which afforded the title compound as a white solid (6.82 g, 54%): m.p. 150°-167° C. The above procedure affords the title compound in sufficient purity to take on to the next step without complications. An analytical sample was obtained by submitting the sample to further purification by flash chromatography (ethyl acetate:methylene chloride:acetic acid, 1:4:0.05) and recrystallization from ethyl acetate (2 times). The resulting product had the following properties: m.p. 154°-156° C.

1. dry with materialTetrabutylammonium chloride (hydrate, 17.8 g) was dried
2. customby azeotroping with benzene (250 mL round bottom flask
3. customequipped with a Dean-Stark apparatus)
4. customThe benzene was removed in vacuo
5. additionwas then added to the
6. customreaction mixture at 23° C
7. extractionextracted with ethyl acetate (500 mL)
8. additionThe aqueous layer was treated with decolorizing carbon
9. filtrationfiltered