反应详情

Imidazole (34 g, 0.5 mole), m-bromoanisole (51 mL, 0.4 mole), potassium carbonate (52 g), and cuprous chloride (2.4 g) in 300 ml N-methyl-2-pyrrolidone was heated at reflux for 4 hours. The cooled mixture was diluted with water and 100 ml concentrated ammonium hydroxide. The product was extracted into toluene-ethylacetate (several times until TLC of aqueous layer showed only a trace amount of product). All the organic extracts were combined, filtered, extracted once with water and then three times with a total of 300 ml 48% hydrobromic acid. The hydrobromic acid extracts were combined and heated at reflux for 6 hours and then concentrated. The residue was redissolved in water and basified first with sodium hydroxide and at the end with sodium bicarbonate to get a final pH of 8. Some isopropyl ether was added to cause the product to crystallize out. The solid was filtered, rinsed with water, and dried at 80° C. in a vacuum oven to obtain 50.9 g (79.5% yield). A small portion of this solid was dissolved in absolute ethanol, filtered, concentrated, and recrystallized. The recrystallized material melted at 169°-170° C.

1. temperatureat reflux for 4 hours
2. extractionThe product was extracted into toluene-ethylacetate (several times until TLC of aqueous layer
3. filtrationfiltered
4. extractionextracted once with water
5. temperatureheated
6. temperatureat reflux for 6 hours
7. concentrationconcentrated
8. dissolutionThe residue was redissolved in water and basified first with sodium hydroxide and at the end with sodium bicarbonate
9. customto get a final pH of 8
10. customto crystallize out
11. filtrationThe solid was filtered
12. washrinsed with water
13. customdried at 80° C. in a vacuum oven
14. customto obtain 50.9 g (79.5% yield)
15. filtrationfiltered
16. concentrationconcentrated
17. customrecrystallized