Iodine → 4-Iodo-3-methoxy-6-pyridin-4-yl-pyridazine

Participants

Reaction Conditions

Reaction Steps

45 ml 1.6M solution of n-butyllithium in hexane are added at −30° C. to a 10.2 g 2,2,6,6-tertamethylpiperidine in 100 ml THF and the mixture stirred at 0° C. for 30 min. After cooling to −75° C. 11.2 g 3-methoxy-6-pyridin-4-yl-pyridazine dissolved 300 ml THF are added and the solution stirred at −75° C. for 35 min. The cold (−75° C.) reaction mixture is subsequently added at a cold (−75° C.) solution of 18.3 g iodine in 400 ml THF (tetrahydrofuran) and stirred at −75° C. for 1.5 h. The reaction is quenched by adding 80 ml methanol/THF (1:1) at −75° C. and 300 ml saturated aqueous NaHCO3 at room temperature and extracted with dichloromethane. The organic layer is ished with 5% aqueous Na2S2O3 and saturated sodium chloride solution, dried (MgSO4) and the solvens removed. The crude product is purified by chromatography on silica gel to yield 14.4 g of 4-iodo-3-methoxy-6-pyridin-4-yl-pyridazine.

Provenance & Evidence