trimethylborane

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of 5-bromo-2-(cyclopropylmethoxy)pyridine (1.88 g) in THF (15 mL) was added 1.6M n-butyllithium-hexane solution (7.25 mL) at −78° C., and the mixture was stirred at the same temperature for 20 min. Trimethylborane (1.29 mL) was added to this solution, and the mixture was stirred at −78° C. for 30 min. The reaction mixture was heated to 0° C., aqueous hydrogen peroxide (30%, 5 mL) and 8M aqueous sodium hydroxide solution (1.55 mL) were added thereto, and the mixture was stirred for 15 min. Water was added to the reaction mixture, the mixture was extracted twice with ethyl acetate, and the combined organic layer was dried over anhydrous magnesium sulfate. The solvent was evaporated under reduced pressure, and the obtained residue was purified by silica gel column chromatography (hexane/ethyl acetate) to give the title compound (855 mg). the mixture was stirred at −78° C. for 30 min the mixture was stirred for 15 min the mixture was extracted twice with ethyl acetate the combined organic layer was dried over anhydrous magnesium sulfate The solvent was evaporated under reduced pressure the obtained residue was purified by silica gel column chromatography (hexane/ethyl acetate)

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 2,2-dimethyl-N-pyridin-4-yl-propionamide (1.6 g, 8.977 mol) was dissolved in anhydrous tetrahydrofuran (20 ml) under nitrogen atmosphere and then cooled to −780, and then 2.5M solution of n-butyl lithium (n-BuLi) in n-hexane (9 ml, 22.443 mmol) was added thereto dropwise and then stirred at 0□ for 2.5 hours until yellow crystals were formed. After cooling the reaction mixture to −78□, trimethylboron (2.5 ml, 22.443 mmol) was added thereto dropwise for 10 minutes, and the temperature was raised slowly up to □0. After stirring for 2 hours, acetic acid (1.9 ml) and 30% w/w aqueous solution of hydrogen peroxide were added dropwise to the reaction solution at 0□, and then after stirring for 30 minutes, water (1 ml) was added thereto dropwise and then stirred at room temperature for 18 hours. Water was added and the mixture was evaporated under reduced pressure, and the residue was extracted by using water and 10% isopropanol/chloroform. The combined organic layer was treated with active carbon and the filtrate was washed with saturated saline solution, dried over anhydrous sodium sulfate (Na2SO4), filtered and evaporated under reduced pressure. The residue was purified by column chromatography on silica eluting with a solvent of dichloromethane:methanol=20:1. The fractions containing the product were collected and evaporated to obtain white solid (1.16 g, 67%). cooled to −780 were formed was added dropwise for 10 minutes the temperature was raised slowly up to □0 After stirring for 2 hours after stirring for 30 minutes dropwise and then stirred at room temperature for 18 hours the mixture was evaporated under reduced pressure the residue was extracted The combined organic layer was treated with active carbon the filtrate was washed with saturated saline solution dried over anhydrous sodium sulfate (Na2SO4) filtered evaporated under reduced pressure The residue was purified by column chromatography on silica eluting with a solvent of dichloromethane The fractions containing the product were collected evaporated