反应详情

Phosphorus oxychloride (POCl3, 3.7 ml, 0.04 mol) (obtained from Aldrich) was added dropwise to 4.4 ml (0.06 mol) of dry dimethylformamide (DMF) at 0° C. under a nitrogen atmosphere. This solution was warmed up slowly to room temperature. Next, a solution of 5 g (0.02 mol) of 10-ethylphenothiazine in dry DMF was added dropwise. The reaction mixture was refluxed at 80° C. for 24 hours and poured into the ice water. This solution was neutralized with potassium hydroxide until the pH reached 6-8. The product was extracted with chloroform. The chloroform extract was dried over anhydrous sodium sulfate, filtered and distilled. The product was recrystallized from methanol. The yield of 10-ethylphenothiazine-3-carbaldehyde (C15H13NOS, FW=255.34) was 3.7 g (66%). The melting point of the product (recrystallized from methanol) was 94-95° C. The 1H-NMR spectrum (100 MHz) of the product in CDCl3 was characterized by the following chemical shifts (δ, ppm): 1.50 (t, J=7.0 Hz, 3H, CH3); 4.02 (q, J=7.0 Hz, 2H, CH2); 6.95-6.39 (m, 5H, Ar); 7.52-7.70 (m, 2H, Ar); 9.83 (s, 1H, CHO).

1. temperatureThe reaction mixture was refluxed at 80° C. for 24 hours
2. extractionThe product was extracted with chloroform
3. extractionThe chloroform extract
4. dry with materialwas dried over anhydrous sodium sulfate
5. filtrationfiltered
6. distillationdistilled
7. customThe product was recrystallized from methanol
8. customThe melting point of the product (recrystallized from methanol)
9. customwas 94-95° C