Phenylacetylene → 3,4-Bis(benzyloxy)-6-(phenylethynyl)pyridazine

Participants

Reaction Steps

A 20 ml microwave vial was charged with 3,4-bis(benzyloxy)-6-chloropyridazine (Intermediate 1; 440 mg, 1.35 mmol), DBU (1230 mg, 8.08 mmol) and ethynylbenzene (413 mgs, 4.04 mmol) in tetrahydrofuran (5 ml) to produce an orange solution. The mixture was purged with nitrogen and dichlorobis(triphenylphosphine)palladium(II) (47.3 mg, 0.067 mmol) and copper(I) iodide (25.6 mg, 0.135 mmol) were added before the whole was subjected to microwave radiation for 1 hour at 80° C. Upon cooling, the resulting mixture was diluted with ethyl acetate and washed with brine and the organic layer was purified by silica chromatography (eluting with 0-30% ethyl acetate-petrol) to yield 3,4-bis(benzyloxy)-6-(phenylethynyl)pyridazine (320 mg, 0.815 mmol, 61% yield).

Provenance & Evidence