反应详情

4.55 Grams (0.025 mole) of 4-benzylideneaminopyridine in 50 milliliters of dry ether was added dropwise to a stirred solution of 2-pyridyl lithium (prepared from 0.03 mole of butyl lithium and 4.74 grams [0.03 mole] of 2-bromopyridine) in 100 ml. of hexane-ether cooled to -30° C. under nitrogen. A purple precipitate was formed which was stirred for 4 hours while allowing the product to warm up to room temperature. The mixture was poured onto ice and the organic layer was separated and extracted with 2 N hydrochloric acid. The acid extracts were combined with the aqueous layer and the combined aqueous medium was basified with 5 N sodium hydroxide and extracted into dichloromethane. After drying over magnesium sulphate, the solvent was removed to leave a solid which was recrystallized from a mixture of toluene and light petroleum (b.p. 100°-120° C.) to afford 2.27 grams of the title compound as free base, m.p. 114°-115° C. The base was converted to its colourless dihydrobromide salt, m.p. 230° (decomposition), by dissolution in the minimum quantity of 2-propanol and adding a solution of hydrogen bromide in dry ether.

1. customA purple precipitate was formed which
2. additionThe mixture was poured onto ice
3. customthe organic layer was separated
4. extractionextracted with 2 N hydrochloric acid
5. extractionextracted into dichloromethane
6. dry with materialAfter drying over magnesium sulphate
7. customthe solvent was removed
8. customto leave a solid which
9. customwas recrystallized from a mixture of toluene and light petroleum (b.p. 100°-120° C.)