反应详情

4.7 g (0.0195 mol) of 3,6-dimethoxyfluoren-9-one and 2.7 g (0.039 mol) of hydroxylammonium chloride are heated at 90° C. in a mixture of 50 ml of ethanol and 20 ml of water. After five hours the solution is poured into ice/water and ethyl acetate is added. The resulting suspension is filtered and the product that has been filtered off is washed with water and dried in vacuo. 4.25 g (86%) of 9-hydroxyimino-3,6-dimethoxyfluorene are obtained in the form of a yellow solid having a melting point of 230-240° C. According to 1H-NMR, that crude product still contains amounts of 3,6-dimethoxyfluoren-9-one. The crude product is, however, used in the subsequent step without being further purified and 3,6-dimethoxyfluoren-9-one is not removed until the end product is purified. Elemental analysis: C15H13NO3 (255.27)

1. additionis added
2. filtrationThe resulting suspension is filtered
3. filtrationthe product that has been filtered off
4. washis washed with water
5. customdried in vacuo