Reacción #7091

Ecuación de reacción

oxindole

n-butyllithium

1,4-diiodobutane

N,N,N′,N′-tetramethylethylenediamine

→

subtitled compound

Rendimiento 50.0%

Spiro[cyclopentane-1,3′-[3H]indol]-2′(1′H)-one

Rendimiento 50.0%

Disolventes

THF

water

THF

Condiciones de reacción

Tratamiento posterior

1. 1
   Extracciónextracted with EtOAc (×2)
2. 2
   Lavadothe combined organic layers were washed with dil. HCl (pH 1), water (×2)
3. 3
   Secadodried (MgSO4)
4. 4
   Otroevaporated
5. 5
   OtroThe residue was purified by column chromatography (SiO2, EtOAc: hexane 1:4)

Procedimiento

To a −25° C. solution of oxindole (2.0 g, 15.0 mmol) in 40 (cm3) of anhydrous THF under N2 was added n-butyllithium (1.6 M in hexanes, 19.7 cm3, 31.5 mmol) drop-wise. To the resulting milky solution was added N,N,N′,N′-tetramethylethylenediamine (4.75 cm3, 31.5 mmol). After 30 min. a solution of 1,4-diiodobutane (21.9 g, 70.6 mmol) in THF (3 cm3) was added and the reaction mixture was allowed to warm to RT and stirred for 14 h. The reaction mixture was poured into water, extracted with EtOAc (×2), then the combined organic layers were washed with dil. HCl (pH 1), water (×2), dried (MgSO4) and evaporated. The residue was purified by column chromatography (SiO2, EtOAc: hexane 1:4) to afford the subtitled compound (1.4 g, 7.5 mmol, 50%) as a tan solid: 1H NMR (CDCl3) δ 1.8–2.2 (m, 8H), 6.94 (dd, J=7.5, 1.0 Hz, 1H), 7.01 (dd, J=7.5, 1.0 Hz, 1H), 7.14–7.25 (m, 2H), 9.30 (br s, 1H).

Fuente