2,4-diMethyl-3-(4,4,5,5-tetraMethyl-1,3,2-dioxaborolan-2-yl)pyridine synthesis

Yield:1421252-89-2 67 %

Reaction Conditions:

with (1,1'-bis(diphenylphosphino)ferrocene)palladium(II) dichloride;potassium acetate in 1,4-dioxane at 20;

Steps:

7.1 Step 1: Synthesis of 2,4-dimethyl-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2- yl)pyridine (B-g-6) :

To a solution of 3-bromo-2,4-dimethylpyridine (300.0 mg, 1.61 mmol) in 1,4- dioxane (10.0 mL) was added bis(pinacolato)diboron (1.2 g, 4.84 mmol), KOAc (474.7 mg, 4.84 mmol) and Pd(dppf)Cl₂ (118.0 mg, 0.16 mmol). The resulting mixture was stirred at room temperature for 16 h. After the reaction was completed, the resulting mixture was concentrated under vacuum. The residue was purified by flash column chromatography with petroleum ether/ethyl acetate (5/1, v/v) to afford 2,4-dimethyl-3-(4,4,5,5-tetramethyl-1,3,2- dioxaborolan-2-yl)pyridine (Compound B-g-6) (250.0 mg, 67%) as a yellow solid. LCMS (ESI, m/z): [M+H]⁺ =234.2.

References:

WO2022/236319,2022,A1 Location in patent:Paragraph 0260-0261