反応 #1140

反応方程式

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

収率 68.0%

溶媒

ethanol

反応条件

後処理

1. 1
   温度The mixture was heated
2. 2
   温度under reflux for 0.25 h
3. 3
   ろ過the solution was filtered through Celite
4. 4
   濃縮concentrated in vacuo
5. 5
   workup.ADDITION1M HCl (10 mL) was added to the residue
6. 6
   抽出After extraction with ethyl acetate (50 mL) the organic phase
7. 7
   その他was separated
8. 8
   抽出The aqueous phase was extracted with ethyl acetate (2×50 mL)
9. 9
   洗浄the combined organic phases were washed with brine (30 mL)
10. 10
    乾燥dried (MgSO4)
11. 11
    濃縮concentrated
12. 12
    その他This material was chromatographed on silica gel with ethyl acetate:hexane (1:1) as eluant

実験手順

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).

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