Reacción #7497

Ecuación de reacción

sodium hydride

ethyl 7-oxo-4-azepanecarboxylate

tert-butyl 2-bromobutanoate

→

diester

Rendimiento 94.4%

ethyl 1-[1-(tert-butoxycarbonyl)propyl]-7-oxo-4-azepanecarboxylate

Rendimiento 94.4%

Disolventes

acetonitrile

Condiciones de reacción

Tratamiento posterior

1. 1
   Temperaturawith reflux condenser, magnetic stirrer
2. 2
   Concentraciónconcentrated to dryness
3. 3
   workup.ADDITIONthe residue was poured on ice/water and neutralised with solid ammonium chloride
4. 4
   ExtracciónThe mixture was extracted three times with CH2Cl2
5. 5
   Secadothe combined organic phases were dried over magnesium sulfate
6. 6
   Filtraciónfiltered
7. 7
   Concentraciónconcentrated to dryness
8. 8
   OtroThe residue was purified by PrepLC (1 kg SiO2, CH2Cl2/MTBE, 85/15)

Procedimiento

In a 150 ml three necked flask fitted with reflux condenser, magnetic stirrer and dropping funnel under inert atmosphere, 5.09 g (27.5 mmoles, 1 eq) of ethyl 7-oxo-4-azepanecarboxylate 28 and 12.27 g (55 mmoles, 2 eq) of tert-butyl 2-bromobutanoate were dissolved in 70 ml of acetonitrile. The temperature was raised to 50° C. and 1.32 g (55 mmoles, 2 eq) of sodium hydride were added portionwise (exothermic). The mixture was stirred one more hour at 50° C. and concentrated to dryness, the residue was poured on ice/water and neutralised with solid ammonium chloride. The mixture was extracted three times with CH2Cl2, the combined organic phases were dried over magnesium sulfate, filtered and concentrated to dryness. The residue was purified by PrepLC (1 kg SiO2, CH2Cl2/MTBE, 85/15) to give 8.5 g of pure diester 29, 69% yield.

Fuente