반응 #1140

반응 방정식

5-bromo-3-(3,3-dibromo-1-methyl-5-pyrrolidin-2-onyl)pyridine

tellurium

Sodium borohydride

ethyl acetate

→

5-bromo-3-(1-methyl-5-pyrrolidin-2-onyl)pyridine

수율 68.0%

용매

ethanol

반응 조건

후처리

1. 1
   온도The mixture was heated
2. 2
   온도under reflux for 0.25 h
3. 3
   여과the solution was filtered through Celite
4. 4
   농축concentrated in vacuo
5. 5
   workup.ADDITION1M HCl (10 mL) was added to the residue
6. 6
   추출After extraction with ethyl acetate (50 mL) the organic phase
7. 7
   기타was separated
8. 8
   추출The aqueous phase was extracted with ethyl acetate (2×50 mL)
9. 9
   세척the combined organic phases were washed with brine (30 mL)
10. 10
    건조dried (MgSO4)
11. 11
    농축concentrated
12. 12
    기타This material was chromatographed on silica gel with ethyl acetate:hexane (1:1) as eluant

실험 절차

Sodium borohydride (862 mg, 22.8 mmol) was dissolved in ethanol (20 mL) and tellurium metal powder (1.45 g, 11.4 mmol) was added in portions. The mixture was heated under reflux for 0.25 h and 5-bromo-3-(3,3-dibromo-1-methyl-5-pyrrolidin-2-onyl)pyridine (775 mg, 1.9 mmol) was added to the solution at 25° C. After stirring for 2 h, ethyl acetate (50 mL) was added and the solution was filtered through Celite and concentrated in vacuo. 1M HCl (10 mL) was added to the residue and the solution was adjusted to pH 11 with solid potassium carbonate. After extraction with ethyl acetate (50 mL) the organic phase was separated. The aqueous phase was extracted with ethyl acetate (2×50 mL) and the combined organic phases were washed with brine (30 mL), dried (MgSO4) and concentrated. This material was chromatographed on silica gel with ethyl acetate:hexane (1:1) as eluant to afford 5-bromo-3-(1-methyl-5-pyrrolidin-2-onyl)pyridine as a solid (329 mg, 68%). M.p. 85°-87° C.; 1H NMR (CDCl3, 300 MHz): δ 8.66 (d, J=2 Hz, 1H), 8.42 (d, J=2 Hz, 1H), 7.68 (t, J=2 Hz, 1H), 4.56 (t, J=7 Hz, 1H), 2.71 (s, 3H), 2.45-2.65 (m, 2H), 1.80-1.95 (m, 2H).

출처