(Pyridin-4-yl)boronic acid → 4-(1,3-Diethyl-5-methyl-1H-pyrazol-4-yl)pyridine

Participants

Reaction Conditions

Reaction Steps

A mixture of 17.05 g (64.6 mmol) of 1,3-diethyl-4-iodo-5-methylpyrazole (from Step D) and 11.9 g (105.4 mmol) of pyridine 4-boronic acid in 300 mL of dioxane was treated with a solution of 44 g (392 mmol) of potassium t-butoxide in 100 mL of water. The resulting mixture was treated with 3.75 g (3.2 mmol) of tetrakis(triphenylphosphine)palladium(0), put under an argon atmosphere and heated at 100° C. for 18 h. The mixture was cooled and partitioned between 1 L of ether and 500 mL of water. The organic layer was separated, dried over MgSO4 and concentrated. Flash chromatography on a Biotage 75S afforded the title compound. 1H-NMR (500 MHz) δ 1.19 (t, J=7.5, 3H), 1.48 (t, J=7.5, 3H), 2.27 (s, 3H), 2.67 (q, J=7.5, 2H), 4.09 (q, J=7.5, 2H), 7.18 (dd, J=2.0, 4.5, 2H), 8.60 (dd, J=2.0, 4.5, 2H).

Provenance & Evidence