تفاعل #1140

معادلة التفاعل

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

المردود 68.0%

المذيبات

ethanol

ظروف التفاعل

المعالجة

1. 1
   درجة الحرارةThe mixture was heated
2. 2
   درجة الحرارةunder reflux for 0.25 h
3. 3
   ترشيحthe solution was filtered through Celite
4. 4
   تركيزconcentrated in vacuo
5. 5
   workup.ADDITION1M HCl (10 mL) was added to the residue
6. 6
   استخلاصAfter extraction with ethyl acetate (50 mL) the organic phase
7. 7
   أخرىwas separated
8. 8
   استخلاصThe aqueous phase was extracted with ethyl acetate (2×50 mL)
9. 9
   غسيلthe combined organic phases were washed with brine (30 mL)
10. 10
    تجفيفdried (MgSO4)
11. 11
    تركيزconcentrated
12. 12
    أخرىThis material was chromatographed on silica gel with ethyl acetate:hexane (1:1) as eluant

الإجراء التجريبي

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).

المصدر