4-Bromo-2-methyl-1-(trifluoromethyl)benzene → 3,4-Bis(benzyloxy)-6-((3-methyl-4-(trifluoromethyl)phenyl)-ethynyl)pyridazine

Participants

Reaction Steps

3,4-bis(Benzyloxy)-6-ethynylpyridazine (Intermediate 5; 3.0 g, 9.48 mmol), copper(I) iodide (0.181 g, 0.948 mmol) and bis(triphenylphosphine)-palladium(II) dichloride (0.333 g, 0.474 mmol) were combined. The reaction vessel was purged with nitrogen, followed by the addition of 4-bromo-2-methyl-1-(trifluoromethyl)benzene (2.493 g, 10.43 mmol), 1,8-diazabicycloundec-7-ene (8.66 g, 56.9 mmol) and tetrahydrofuran (32 ml) before the resulting mixture was allowed to stir at room temperature overnight. The reaction was quenched with brine and extracted into ethyl acetate (×2) and the combined organic extracts were washed with brine, dried (MgSO4) and concentrated in vacuo to afford a dark brown gum. The gum was purified by column chromatography (silica, 0-50% ethyl acetate in petrol) to afford 3,4-bis(benzyloxy)-6-((3-methyl-4-(trifluoromethyl)phenyl)-ethynyl)pyridazine as a dark brown oil (1.22 g, 27%).

Provenance & Evidence