Ethyl Acrylate → ethyl(E)-3-(3-chloro-6-pyridazinyl)-2-propenoate

Participants

Reaction Conditions

Reaction Steps

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.

Provenance & Evidence