3-chloro-6-(1-ethoxyethenyl)Pyridazine synthesis

Yield:479628-47-2 41.5%

Reaction Conditions:

with trans-bis(triphenylphosphine)palladium dichloride;triethylamine in N,N-dimethyl-formamide at 100; for 16 h;

Steps:

19.1 Step 1. 3-Chloro-6-(l-ethoxyvinyl)pyridazine

A mixture of 3,6-dichloropyridazine (1.00 g, 6.71 mmol), tributyl(l- ethoxyvinyl)stannane (2.322 mL, 7.05 mmol), bis(triphenylphosphine)palladium(II) chloride (0.141 g, 0.201 mmol), triethylamine (1.029 mL, 7.38 mmol) in DMF (25 mL) was heated at 100 °C for 16 hr. The solvent was removed under vacuum. The residue was diluted with ethyl acetate (150 mL), washed with water (3 x 40 mL) and brine (40 mL), and dried over anhydrous MgSCri. The desired product, 3-chloro-6-(l- ethoxyvinyl)pyridazine (0.514 g, 2.78 mmol, 41.5 % yield) was isolated as a white solid by ISCO chromatography (80 g silica gel, solid loading, 5-20% ethyl acetate/hexane). LCMS m/z = 185.0 (M + H)⁺.

References:

WO2021/222153,2021,A1 Location in patent:Page/Page column 49-50