反应详情

温度

80 °C

To a mixture of 6.5 g (47.7 mmol) of dehydrated zinc chloride and 150 ml of toluene were added 14 ml (180.1 mmol) of N,N-dimethylformamide (DMF) and 10.0 g (44.0 mmol) of 10-ethylphenothiazine (4a). Thereto was gradually added dropwise 27.0 g (176.1 mmol) of phosphorus oxychloride at room temperature to 35° C. The resultant mixture was reacted at 73° to 78° C. for 3 days and then poured into 200 ml of water. This mixture was neutralized with sodium carbonate, stirred at 80° C. for 3 hours, and then subjected to liquid separation. The aqueous layer was extracted with ethyl acetate three times, and the resultant organic layer collected was dried with magnesium sulfate and concentrated. The residue was recrystallized from an isopropanol/ethyl acetate mixed solvent to obtain 4.96 g of 3,7-diformyl-10-ethylphenothiazine (2a). Yield, 58.7%; m.p., 132°-145° C. MS: 284 (M+), 283, 268, 254, 236, 226, 198, 154. 1H-NMR (δ; ppm in CDCl3): 1.50 (t, J=7.0.Hz, 3H), 4.00 (q, J=7.0 Hz, 2H), 6.96 (d, J=8.5 Hz, 2H), 7.58 (s, 2H), 7.65 (d, J=8.5 Hz, 2H), 9.85 (s, 2H).

1. customsubjected to liquid separation
2. extractionThe aqueous layer was extracted with ethyl acetate three times
3. customthe resultant organic layer collected
4. dry with materialwas dried with magnesium sulfate
5. concentrationconcentrated
6. customThe residue was recrystallized from an isopropanol/ethyl acetate mixed solvent