3-Pyridine aldoxime → 3-(4,5-Bis-trimethylsilanyl-isoxazol-3-yl)-pyridine

Participants

Reaction Conditions

Reaction Steps

To a solution of anhydrous THF (250 ml) containing 3-pyridinealdoxim (61) (18.87 g, 154.7 mmol) were added 20.57 g (1.0 eq) of N-chlorosuccinimide. After the addition, the resulting solution was stirred for 18 hours at 65° C. Then the temperature of the reaction mixture was lowered to −30° C. and 1,2-bis-trimethylsilanyl-ethyne was added (26.4 g, 170.4 mmol), subsequently followed by triethylamine (2 eq, 42 ml, dropwise), while keeping the temperature <−25° C. After stirring for another 30 minutes, the mixture was allowed to warm to ambient temperature, diluted with ethyl acetate, washed three times with a saturated NaHCO3 solution, dried (Na2SO4), filtered and concentrated. The resulting residue was purified by flash chromatography (diethyl ether/PE 1/1) to afford 3-(4,5-bis-trimethylsilanyl-isoxazol-3-yl)-pyridine (62) as an oil (4.45 g, 17%). 1H-NMR (400 MHz, CDCl3): δ 8.70 (dd, J=5 Hz, 2 Hz, 1H), 8.68 (d, J=2 Hz, 1H), 7.76 (dt, J=8 Hz, 2 Hz, 1H), 7.41-7.37 (m, 1H), 0.46 (s, 9H), 0.011 (s, 9H).

Provenance & Evidence