反应详情

To a solution of 6.5 g of 5-bromo-2-methoxypyridine-3-carboxaldehyde in 30 ml of tetrahydrofuran under nitrogen was added 200 ml of methanol followed by 4.6 g of 4-chloroacetophenone. Then, a solution of 6.6 g of 85% potassium hydroxide in 15 ml of water was added. The mixture warmed, became yellow, and deposited a thick precipitate. It was then stirred mechanically for about 1.5 hours until the temperature fell back to about 25° C. It was then further cooled in an ice bath and neutralized by the addition of 20 ml of aqueous 5M hydrochloric aid in small portions. The resulting pasty mixture was poured into 400 ml of water, acidified to a pH of 1 with aqueous 1N hydrochloric acid and then filtered. The moist product was boiled with 2-propanol/ethyl acetate (3:1), cooled and filtered. The filter cake was dried under reduced pressure to give (E)-3-(5-bromo-2-methoxy-3-pyridinyl)-1-(4-chlorophenyl)-2-propen-1-one as a pale yellow solid melting at about 168.5°-171.5° C.

1. temperatureThe mixture warmed
2. customfell back to about 25° C
3. temperatureIt was then further cooled in an ice bath
4. additionneutralized by the addition of 20 ml of aqueous 5M hydrochloric aid in small portions
5. filtrationfiltered
6. temperaturecooled
7. filtrationfiltered
8. customThe filter cake was dried under reduced pressure