1,4-Dioxane → Ethyl 1-[(6-chloropyridin-3-yl)methyl]-4-thioxo-1,4-dihydropyrido[2,3-c]pyridazine-3-carboxylate

Participants

Reaction Conditions

Reaction Steps

Ethyl 1-[(6-chloropyridin-3-yl)methyl]-4-oxo-1,4-dihydropyrido[2,3-c]pyridazine-3-carboxylate (490 mg, 1.42 mmol) was suspended in toluene (5 mL) and dioxane (5 mL) and placed into a preheated oil bath at 110° C. The mixture was treated with Lawesson's Reagent (316 mg, 0.782 mmol, 0.55 equiv) portionwise over 45 minutes and stirred for an addition 30 minutes at 110° C. The mixture was cooled to ambient temperature and concentrated in vacuo. The residue was purified by silica gel gradient chromatography (100:0 to 50:50; hexanes:ethyl acetate), providing the titled compound as a brown foam.

Provenance & Evidence