1H-Indole, 4-(4,4,5,5-tetraMethyl-1,3,2-dioxaborolan-2-yl)-6-(trifluoroMethyl)- synthesis

Yield:955978-82-2 89.1%

Reaction Conditions:

with palladium (II) [1,1'-bis(diphenylphosphanyl)ferrocene] dichloride;anhydrous potassium acetate in 1,4-dioxane at 90; for 3 h;Inert atmosphere;

Steps:

63.1 Step 1. 4-(4,4,5,5-tetramethyl-l,3,2-dioxaborolan-2-yl)-6-(trifluoromethyl)-1H-indole (401- a)

4-Bromo-6-(trifluoromethyl)-1H-indole (2.0 g, 7.57 mmol), 4,4,5,5-tetramethyl-2-(4,4,5,5- tetramethyl-l,3,2-dioxaborolan-2-yl)-l,3,2-dioxaborolane (2.31 g, 9.09 mmol), KO Ac (2.23 g, 22.7 mmol) and Pd(dppf)C12 (554 mg, 757 umol) in dioxane (30 mL) was de-gassed and then heated to 90°C for 3 hr under N2. The mixture was filtered and concentrated. The residue was purified by flash chromatography (ISCO; 25 g SepaFlash Silica Flash Column, petroleum ether/EtOAc with EtOAc from 0-30%, 100 mL/min, 254 nm) to afford the title compound 401-a (2.1 g, 89.1% yield) as a yellow solid. MS (ESI) [M+H]⁺ m/z 407.1.

References:

WO2022/104206,2022,A1 Location in patent:Page/Page column 138-139