反应详情

温度

111 °C

A suspension of 3-chloro-6-iodopyridazine (2.4 g, 10 mmol), ethyl acrylate (4.4 mL, 40 mmol), palladium(II) acetate (90 mg, 0.40 mmol) and tri(o-tolyl)phosphine (366 mg, 1.20 mmol) in DMF (10 mL) and diisopropylethyl amine (5 mL) was stirred with heating (111° C. oil-bath) for 3.5 h, cooled to room temperature, diluted with H2O (50 mL) and extracted with EtOAc (300 mL). The extract was washed (brine) and dried. After solvent removal at reduced pressure, the residue was chromatographed (14% to 20% EtOAc/hexane) to give 174 mg (8%) of ethyl(E)-3-(3-chloro-6-pyridazinyl)-2-propenoate as a brown solid, mp 106-110° C. IR 2928, 1715, 1186 cm−1; 1H NMR (CDCl3) δ 1.38 (t, J=7.5 Hz, 3H, CH2CH3), 4.33 (q, J=7.5 Hz, 2H, CH2CH3), 7.98 (d, J=16.2 Hz, 1H, CH═CHCO), 7.57 (d, J=8.4 Hz, 1H, 4-ArH), 7.63 (d, J=8.4 Hz, 1H, 5-ArH), 7.86 ppm (d, J=16.2 Hz, 1H, CH═CHCO). HRMS calcd C9H9ClN2O2 [M+H]+ 213.0425. found 213.0431.

1. temperaturecooled to room temperature
2. extractionextracted with EtOAc (300 mL)
3. washThe extract was washed (brine)
4. customdried
5. customAfter solvent removal at reduced pressure
6. customthe residue was chromatographed (14% to 20% EtOAc/hexane)