反应详情

温度

55 °C

Methyl 3-(3-bromo-4-hydroxy-6-methyl-2-oxopyridin-1(2H)-yl)-4-methylbenzoate (4) (1.9 kg, 5.4 moles), N,N-dimethylformamide (4.8 L) and powdered K2CO3 (1.1 kg, 8.1 moles) were mixed together and heated to 55° C. under nitrogen. 2,4-difluorobenzyl chloride (964 g, 5.9 moles) was added at a rate such that the temperature was maintained below 65° C. After the addition, the mixture was heated at 65° C. for 3.5 hours. After 3 hours the reaction was complete and the reaction mixture was cooled to 20-25° C. with the addition of 19 L water. The solid was filtered and washed with 15 L water. The crude product was then purified by trituration in refluxing methanol (4 L). The mixture was cooled and the solid filtered to yield 2.32 kg (90%) product. 1H NMR (300 MHz, CDCl3) δ 1.90 (s, 3H), 2.11 (s, 3H), 3.87 (s, 3H), 5.25 (s, 2H), 6.11 (s, 1H), 6.88 (dt, J=4.8, 1.8 Hz, 1H), 6.96 (t, J=4.8 Hz, 1H), 7.42 (d, J=6 Hz, 1H), 7.59 (q, J=4.8 Hz, 1H), 7.74 (s, 1H), 8.02 (d, J=6 Hz, 1H). Anal. Cald. for C22H18BrF2NO4: C, 55.25; H, 3.79; N, 2.93. Found: C, 55.34; H, 3.83; N, 3.14.

1. temperaturewas maintained below 65° C
2. additionAfter the addition
3. temperaturethe mixture was heated at 65° C. for 3.5 hours
4. filtrationThe solid was filtered
5. washwashed with 15 L water
6. customThe crude product was then purified by trituration
7. temperaturein refluxing methanol (4 L)
8. temperatureThe mixture was cooled
9. filtrationthe solid filtered