2-Formylthiophene-4-boronic acid pinacol ester synthesis

Yield:881381-12-0 88%

Reaction Conditions:

with potassium acetate;(1,1'-bis(diphenylphosphino)ferrocene)palladium(II) dichloride in 1,2-dimethoxyethane at 150; for 0.333333 h;Microwave;

Steps:

42

To 4-bromo-2-thiophenecarbaldehyde (500 mg, 2.61 mmol) in DME (18 mL), bis(pinacolato)diboron (865 mg, 3.403 mmol), potassium acetate (667 mg, 6.81 mmol) and PdCI₂(dppf) (96 mg, 0.131 mmol) were added. The reaction mixture was heated by microwave at 150⁰C for 20 minutes. Then all the solvent was evaporated. The residue was partitioned between ethyl acetate (100 mL) and water (100 mL). The water layer was extracted with ethyl acetate (2x100 mL). The combined organic phase was washed with brine (100 mL) and dried with Mg₂SO₄ and concentrated. The crude product was purified by Combiflash (Hexane/ethyl acetate, 1% -30 % ethyl acetate, 20 min.) to give title compound (550 mg, 88 %). LC/MS: m/z, 238.2 (M+H), 1.88 min

References:

WO2006/34317,2006,A2 Location in patent:Page/Page column 94