3-CHLORO-2-ISOBUTYLPYRIDINE synthesis

Yield:1355066-88-4 53%

Reaction Conditions:

with potassium carbonate;silver(l) oxide;dichloro(1,1'-bis(diphenylphosphanyl)ferrocene)palladium(II)*CH₂Cl₂ in tetrahydrofuran at 75; for 7 h;Inert atmosphere;

Steps:

49

3-Chloro-2-iodopyridine (1.552 g, 6.482 mmol), isobutylboronic acid (0.725 g, 7.112 mmol), potassium carbonate (2.7 g, 0.0195 mol) and silver oxide (3.8 g, 0.0164 mol) were suspended in THF (25 mL). The mixture was degassed three times and 1,1-Bis(diphenylphosphino)ferrocene-palladium(11)dichloride dichloromethane (1:1) (0.520 g, 0.637 mmol) was added. The reaction mixture was heated at 75° C. under nitrogen for seven hours. The mixture was diluted EtOAc (15 mL) and washed with an aqueous solution of hydrochloric acid (2.0 M, 2×15 mL). The organic layer was discarded and the aqueous layer basified with careful addition of a saturated aqueous solution of sodium hydrogen carbonate (50 mL). The product was extracted with EtOAc (2×15 mL). The organics were combined, dried over sodium sulfate, filtered, and concentrated in vacuo. The resulting crude was purified by silica gel chromatography eluting with 0 to 5% EtOAc in heptane to yield the title compound as a colourless oil (0.582 g, 53% yield).¹H NMR (400 MHz, d₆-DMSO): δ 0.87-0.89 (d, 6H), 2.09-2.17 (m, 1H), 2.72-2.74 (d, 2H), 7.24-7.27 (m, 1H), 7.83-7.86 (m, 1H), 8.44-8.45 (m, 1H).LCMS Rt=1.30 minutes MS m/z 170 [MH]⁺

References:

US2012/10183,2012,A1 Location in patent:Page/Page column 52; 53