反应详情

温度

110 °C

4,6-Dichloro-pyridazine-3-carboxylic acid methyl ester (200 mg, 0.966 mmol), p-toluidine (104 mg, 0.966 mmol) and N,N-diisopropylethylamine (0.34 mL, 1.93 mmol) were dissolved in N,N-dimethylacetamide (2.4 mL), then heated at 110° C. for 1 h. The reaction mixture was cooled, then poured into ethyl acetate and water. The aqueous layer was extracted with ethyl acetate, and then the combined organic layers were washed with saturated aqueous sodium chloride solution, dried over sodium sulfate, filtered, and concentrated in vacuo. Purification by chromatography (silica, 0 to 50% ethyl acetate in hexanes) gave 6-chloro-4-p-tolylamino-pyridazine-3-carboxylic acid methyl ester (214 mg, 79%) as an off-white solid. 1H NMR (300 MHz, CHLOROFORM-d) δ ppm 9.61 (br. s., 1H) 7.23-7.32 (m, 2H) 7.13 (d, J=7.9 Hz, 2H) 6.96 (s, 1H) 4.08 (s, 3H) 2.41 (s, 3H); LCMS (EI/CI) m/z: 278 [M+H].

1. temperatureThe reaction mixture was cooled
2. extractionThe aqueous layer was extracted with ethyl acetate
3. washthe combined organic layers were washed with saturated aqueous sodium chloride solution
4. dry with materialdried over sodium sulfate
5. filtrationfiltered
6. concentrationconcentrated in vacuo
7. customPurification by chromatography (silica, 0 to 50% ethyl acetate in hexanes)