3-Bromo-2,6-dimethylpyridine → 2,6-Dimethyl-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridine

HRID 2103665Notes

Reaction equation

Br[C:2]1[C:3]([CH3:9])=[N:4][C:5]([CH3:8])=[CH:6][CH:7]=1.C([Li])CCC.C(O[B:19]1[O:23][C:22]([CH3:25])([CH3:24])[C:21]([CH3:27])([CH3:26])[O:20]1)(C)C>CCOCC>[CH3:9][C:3]1[C:2]([B:19]2[O:23][C:22]([CH3:25])([CH3:24])[C:21]([CH3:27])([CH3:26])[O:20]2)=[CH:7][CH:6]=[C:5]([CH3:8])[N:4]=1

Participants

Conditions

Temperature: -78 °C

Procedure

A solution of 3-bromo-2,6-dimethylpyridine (5.10 g, 27.4 mmol) in anhydrous ether (160 ml) cooled to −78° C. under a nitrogen atmosphere was treated dropwise with n-butyl lithium (4.1 ml, 10 M in hexane) and stirred at −78° C. for 45 minutes. 2-isopropoxy-4,4,5,5-tetramethyl-[1,3,2]dioxaborolane (10.2 g, 54.8 mmol) in 20 ml of ether was added dropwise at −78° C. and stirred at −78° C. for 3 hours. The mixture was quenched with 10 ml of isopropanol, and allowed to warm to room temperature. 150 ml of saturated aqueous NaCl solution was added. The aqueous phase was separated and extracted with dichloromethane (100 ml×6). The combined organic phases were dried and concentrated to provide the title compound as light brown oil (6.29 g, 98.4%). 1H NMR (300 MHz, CDCl3) δ ppm 7.92 (d, J=7.46 Hz, 1H) 6.96 (d, J=7.80 Hz, 1H) 2.73 (s, 3H) 2.53 (s, 3H) 1.34 (s, 12H). MS: (M+H)+=234.

Workup

stirringstirred at −78° C. for 3 hours
customThe mixture was quenched with 10 ml of isopropanol
temperatureto warm to room temperature
addition150 ml of saturated aqueous NaCl solution was added
customThe aqueous phase was separated
extractionextracted with dichloromethane (100 ml×6)
customThe combined organic phases were dried
concentrationconcentrated

Sources & evidence

ORD record: ord-10c50645641b44f4b121a4b16feb5dce
Source dataset: uspto-grants-2009_08
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07576110B2

Reaction notes

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