反应详情

温度

60 °C

A suspension of 1007 g of 6-methoxy-3-quinolinediazonium fluoroborate taken in 9 l of toluene is heated to 60° C. in 85 minutes. A release of gas is observed at 60° C. The reaction medium is then gradually heated further for 90 minutes to 70-72° C. After having been kept at 72° C. for 90 minutes, the medium is then gradually heated again to 85° C. After cooling and stirring overnight, 4 l of ice-cold water are added to the suspension. After having stirred for 15 minutes, 2.5 l of ethyl acetate are added. After having stirred for 45 minutes, the pH is adjusted to pH=7-7.5 by adding 47% sodium hydroxide (250 ml). The medium is stirred for 30 minutes and then separated by settling out for 1 hour. The lower aqueous phase is re-extracted with ethyl acetate. The organic phases are combined together and washed with water. The solution is filtered and then concentrated under reduced pressure so as to give 655 g of crude 3-fluoro-6-methoxyquinoline. The crude product is distilled under reduced pressure. The distillation fractions (bp 103-110° C. under 1 mbar) containing the expected product are combined together. 498.9 g of 3-fluoro-6-methoxyquinoline (76%) are thus obtained in the form of a white solid which melts at 51-53° C.

1. customis observed at 60° C
2. temperatureThe reaction medium is then gradually heated further for 90 minutes to 70-72° C
3. temperaturethe medium is then gradually heated again to 85° C
4. temperatureAfter cooling
5. stirringAfter having stirred for 15 minutes
6. stirringAfter having stirred for 45 minutes
7. stirringThe medium is stirred for 30 minutes
8. customseparated
9. waitby settling out for 1 hour
10. extractionThe lower aqueous phase is re-extracted with ethyl acetate
11. washwashed with water
12. filtrationThe solution is filtered
13. concentrationconcentrated under reduced pressure so as