반응 #50538

반응 방정식

ammonium chloride

n-butyl lithium

4-bromo-2-(4-methylphenyl)pyridine

dimethylformamide

→

4-formyl-2-(4-methylphenyl)pyridine

용매

tetrahydrofuran

반응 조건

후처리

1. 1
   온도to warm slowly to room temperature over a period of 2 hours
2. 2
   기타The mixture was partitioned between methylene chloride and water
3. 3
   기타the organic layer separated
4. 4
   건조dried over sodium sulfate
5. 5
   기타the solvent evaporated under reduced pressure
6. 6
   기타the residue flash-chromatographed on silica gel
7. 7
   세척eluting with 20% ethyl acetate in heptane

실험 절차

A solution of 4-bromo-2-(4-methylphenyl)pyridine (3.2 g) in 30 ml of tetrahydrofuran was cooled to -70° C., and 1.6M n-butyl lithium (8.1 ml) was added. The solution was stirred for 15 minutes at -70° C., and then dimethylformamide (1.3 ml) added. The mixture was allowed to warm slowly to room temperature over a period of 2 hours, and aqueous saturated ammonium chloride solution added. The mixture was partitioned between methylene chloride and water, the organic layer separated and dried over sodium sulfate, the solvent evaporated under reduced pressure, and the residue flash-chromatographed on silica gel, eluting with 20% ethyl acetate in heptane, to yield 0.81 g of 4-formyl-2-(4-methylphenyl)pyridine, m.p. 66° C.

출처