反応 #9422

反応方程式

iodoethane

oxindole

n-butyl lithium

NH4Cl

N,N,N′,N′-tetramethylethylenediamine

→

3-ethyl-indol-2-one

収率 2.9%

溶媒

THF

反応条件

後処理

1. 1
   抽出extracted with EtOAc (2×)
2. 2
   洗浄the combined organic layers were washed with dil. HCl, water, brine
3. 3
   乾燥dried (MgSO4)
4. 4
   濃縮concentrated
5. 5
   その他The residual oil was triturated with hexane
6. 6
   その他to afford the crude product (24.5 g, 51%)
7. 7
   その他A sample (3 g) was recrystallized from EtOAc/hexane

実験手順

A solution of oxindole (40 g, 0.3 mol) in dry THF (400 ml) under N2 was cooled to −25° C. and treated drop wise with n-butyl lithium (2.5M in hexanes, 240 ml, 0.6 mol). To the resulting solution was added N,N,N′,N′-tetramethylethylenediamine (90.4 ml, 0.6 mol). After 30 min. iodoethane (48 ml, 0.6 mol) was added and the reaction mixture was allowed to warm to room temperature and stirred over night. The reaction mixture was poured into aqueous NH4Cl solution, extracted with EtOAc (2×) and the combined organic layers were washed with dil. HCl, water, brine, dried (MgSO4) and concentrated. The residual oil was triturated with hexane to afford the crude product (24.5 g, 51%). A sample (3 g) was recrystallized from EtOAc/hexane to obtain 3-ethyl-indol-2-one (1.4 g), m.p. 100–101° C.; 1H-NMR (DMSO-d6) δ 0.76 (t, 3H, J=7.5 Hz), 1.8–2.0 (m, 2H), 3.38 (t, 3H, J=5.7 Hz), 6.8 (dt, 1H, J=7.69, 0.45 Hz), 6.93 (dt, 1H, J=7.45, 1.10 Hz), 7.15 (m, 1H), 7.22 (m, 1H), 10.3 (s, 1H); MS (ESI) m/z 270 [M+H].

出典