反应详情

A mixture of 28 g of 3-chloro-2',5'-difluoro-2-hydroxy-4-methoxybenzophenone and 26 g of hydroxylamine HCl in 250 ml pyridine is refluxed for three hours. Pyridine is evaporated and the residue partitioned between ethyl acetate and 5% HCl. The ethyl acetate extract is washed with water, dried over Na2SO4 and evaporated to give a solid product as a mixture of isomers. The solid is heated at 200°-210° C. for approximately 30-45 minutes and recrystallized from toluene giving E-3-chloro-2',5'-difluro-2-hydroxy-4-methoxybenzophenone oxime, mp 209°-210° C.

1. temperatureis refluxed for three hours
2. customPyridine is evaporated
3. customthe residue partitioned between ethyl acetate and 5% HCl
4. extractionThe ethyl acetate extract
5. washis washed with water
6. dry with materialdried over Na2SO4
7. customevaporated
8. customto give a solid product
9. additionas a mixture of isomers
10. temperatureThe solid is heated at 200°-210° C. for approximately 30-45 minutes
11. customrecrystallized from toluene