3,6-Dichloropyridazine → 3-Chloro-6-(thiophen-2-yl)pyridazine

Participants

Reaction Conditions

Reaction Steps

A mixture of tri-n-butylstannylthiophene (6.26 g, 16.78 mmol), 3,6-dichloropyridazine (5.00 g, 33.56 mmol), tetrakis(triphenylphosphine)palladium(0) (0.20 g, 0.17 mmol) and few crystals of 1,2-ditert-butyl of 2,6-di-tert-butyl-4-methylphenolo in dry DMF (50 mL) was deareated twice with nitrogen. The reaction mixture was heated at 80° C. for 6 hours and, after cooling, poured onto water (100 mL). A white precipitate was collected, washed several times with water and dried under vacuum. This solid was taken up with ether (25 mL) and filtered to afford 3.01 g of almost pure product. Finally, this solid was crystallized from MeOH—H2O to give the pure target compound as white crystals (1.56 g, 7.90 mmol, 47.3% yield). Mp 155° C.; 1H NMR (CDCl3) δ 7.75 (1H, d, 2J=11.0), 7.68 (1H, d, 2J=3.6), 7.54 (1H, d, 2J=5.0), 7.51 (1H, d), 7.18 (1H, dd).

Provenance & Evidence