反应详情

3-Benzylpyridine (13.52 g, 0.080 mole) and nitric acid (70%, 100 ml) are stirred at 50° C. for 6 hr. The solution is poured into ice-water (1500 ml). The mixture is made alkaline by the careful addition of 50% aqueous sodium hydroxide and then extracted 4 times with 300 ml of ether. The extracts are washed with brine, dried (MgSO4), filtered, and concentrated. The crude product is crystallized from acetone-hexane giving 5.67 g of 3-(4'-nitrobenzyl)pyridine. The filtrate is concentrated and the residue is chromatographed in two equal portions (4.66 g each) over two Merck size C Lobar columns. The columns are eluted with 50% ethyl acetate-hexane. A less polar product [1.83 g, 3-(2'-nitrobenzyl)pyridine], mixed fractions (1.67 g), and additional 3-(4'-nitrobenzyl)pyridine (2.55 g) after crystallization from acetone-hexane, total 7.92 g, 0.037 mole, 46%). Two recrystallizations from acetone-hexane gives the titled product as colorless needles, having a melting point of 87°-88° C.

1. extractionextracted 4 times with 300 ml of ether
2. washThe extracts are washed with brine
3. dry with materialdried (MgSO4)
4. filtrationfiltered
5. concentrationconcentrated
6. customThe crude product is crystallized from acetone-hexane giving 5.67 g of 3-(4'-nitrobenzyl)pyridine
7. concentrationThe filtrate is concentrated
8. customthe residue is chromatographed in two equal portions (4.66 g each) over two Merck size C Lobar columns
9. washThe columns are eluted with 50% ethyl acetate-hexane
10. additionA less polar product [1.83 g, 3-(2'-nitrobenzyl)pyridine], mixed fractions (1.67 g), and additional 3-(4'-nitrobenzyl)pyridine (2.55 g)
11. customafter crystallization from acetone-hexane, total 7.92 g, 0.037 mole, 46%)
12. customTwo recrystallizations from acetone-hexane