Pyridine → 2-[N-(5-bromo-2-hydroxybenzyl)-N-ethylamino]-5-cyanopyridine

Participants

Reaction Steps

2-[N-(5-Bromo-2-hydroxybenzyl)-N-ethylamino]pyridine-5-carboxamide (example 4) (1.0 g, 2.85 mmol) was suspended in tetrahydrofuran (15 ml) and the stirred solution treated with pyridine (0.46 ml, 0.46 g, 5.7 mmol) and trifluoroacetic anhydride (0.9 ml, 1.35 g, 6.4 mmol) at ambient temperature (slight exotherm). A yellow colour became apparent and the solid dissolved in the THF. The solution was left standing at ambient temperature overnight, then further pyridine (0.46 ml, 5.7 mmol) and TFAA (0.90 ml, 6.4 mmol) were added and the reaction was again left overnight. The mixture was evaporated to low volume, saturated sodium bicarbonate solution was added and the mixture stirred at ambient temperature for 30 minutes, evaporated to low volume and the resultant white precipitate filtered, washed with water and air dried to give 2-[N-(5-bromo-2-hydroxybenzyl)-N-ethylamino]-5-cyanopyridine as a white solid (1.0 g, 100%).

Provenance & Evidence