1H-Pyrrolo[2,3-b]pyridine-1-carboxylic acid, 5-borono-2,3-dihydro-3-Methyl-, 1-(1,1-diMethylethyl) este synthesis

Yield:1111637-67-2 51%

Reaction Conditions:

Stage #1: C₁₃H₁₇BrN₂O₂with n-butyllithium;Triisopropyl borate in tetrahydrofuran;hexanes at -78; for 2 h;
Stage #2: with hydrogenchloride;water at 0; pH=7;

Steps:

7

Step 7:To a stirring solution of compound 63 (460 mg, 1.47 mmol) and triisopropylborate (691 mg, 3.67 mmol) in 25 mL dry THF at -78 ° C was added Butyl lithium solution (2.5 M in hexanes, 1.47 mL, 3.67 mmol) dropwise under nitrogen. The reaction was stirred at -78 ° C and monitored with LCMS. 2hr later, LCMS indicated reaction complete. Reaction was quenched with 25 mL water and concentrated under reduced pressure to a total volume of about 15 mL. The residual was washed with ether (2X10 mL) and the aqueous later was placed in an ice-water bath. While stirring, 10 N HCI aqueous solution was carefully added dropwise until pH = 7. Filtration and washing with ice-water (3x5 mL) gave compound 64 (208 mg, 51%) as a white solid.

References:

WO2009/16460,2009,A2 Location in patent:Page/Page column 50-51