반응 #1135

반응 방정식

pyridine

trifluoroacetic acid

→

5-(4-fluorophenyl)-3-(2-piperidinyl)pyridine

용매

dichloromethane

반응 조건

후처리

1. 1
   기타The solvents were removed in vacuo
2. 2
   workup.DISSOLUTIONthe crude material dissolved in ethyl acetate (50 mL)
3. 3
   workup.ADDITIONSaturated sodium carbonate solution (30 mL) was added
4. 4
   기타the organic layer separated
5. 5
   추출The aqueous phase was extracted with two further portions of ethyl acetate (2×30 mL)
6. 6
   세척the combined organic extracts washed with brine (20 mL)
7. 7
   건조dried (Na2SO4)
8. 8
   농축concentrated in vacuo
9. 9
   기타The residue was chromatographed on silica gel with ethyl acetate

실험 절차

The above-described pyridine derivative (1.25 g, 3.5 mmol) was dissolved in a mixture of dichloromethane (10 mL) and trifluoroacetic acid (10 mL) and this was stirred at 25° C. for 18 h. The solvents were removed in vacuo and the crude material dissolved in ethyl acetate (50 mL). Saturated sodium carbonate solution (30 mL) was added and the organic layer separated. The aqueous phase was extracted with two further portions of ethyl acetate (2×30 mL), the combined organic extracts washed with brine (20 mL), dried (Na2SO4) and concentrated in vacuo. The residue was chromatographed on silica gel with ethyl acetate, then methanol:ethyl acetate (1:9) as eluant to afford 5-(4-fluorophenyl)-3-(2-piperidinyl)pyridine, 940 mg, 100%. NMR (CDCl3, 300 MHz): δ 8.69 (d, J=2 Hz, 1 H), 8.55 (d, J=2 Hz, 1 H), 7.93 (t, J=2 Hz, 1 H), 7.56 (m, 2 H), 7.16 (app. tm, J=9 Hz, 2 H), 3.18 (d, J=12 Hz, 1 H), 2.83 (td, J=12, 3 Hz, 1 H), 2.61 (bs exch., 1 H), 1.92 (m, 2 H), 1.45-1.75 (m, 6 H).

출처