1-Chloro-3-iodobenzene → 3,4-Bis(benzyloxy)-6-((3-chlorophenyl)ethynyl)pyridazine

Participants

Reaction Conditions

Reaction Steps

To a solution of 1-chloro-3-iodobenzene (0.862 g, 3.62 mmol) in dry tetrahydrofuran (11 ml) was added copper(I) iodide (0.063 g, 0.33 mmol), bis(triphenylphosphine)-palladium(II) chloride (0.115 g, 0.16 mmol) and 1,8-diazabicycloundec-7-ene and (DBU; 2.97 ml, 19.72 mmol). The reaction was then purged and evacuated with nitrogen several times before 3,4-bis(benzyloxy)-6-ethynylpyridazine (Intermediate 5; 1.04 g, 3.29 mmol) was added. The reaction vessel was sealed and heated to 80° C. for 1 hour. Upon cooling, the resultant mixture was partitioned between ethyl acetate and water. The combined organic portions were washed with water (×2) and brine, dried (MgSO4), filtered and concentrated to give a brown oil. The crude oil was purified by silica chromatography (eluting with 0-20% ethyl acetate in petrol) to yield 3,4-bis(benzyloxy)-6-((3-chlorophenyl)ethynyl)pyridazine as a yellow solid (yield=30%).

Provenance & Evidence