Reaktion #499573

Reaktionsgleichung

1,5-diiodopentane

oxindole

n-butyllithium

ammonium chloride

N,N,N′,N′-tetramethylethylenediamine

→

spiro[cyclohexane-1,3′-[3H]indol]-2′-(1′H)one

Ausbeute 69.6%

Lösungsmittel

tetrahydrofuran

EtOAc

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONwere added
2. 2
   SonstigeAfter 15 min. the layers were separated
3. 3
   Extraktionthe aqueous phase was extracted
4. 4
   ExtraktionThe combined organic layers were extracted with hydrochloric acid (1N)
5. 5
   Waschenwashed with brine (500 mL)
6. 6
   Trocknendried (MgSO4)
7. 7
   Einengenconcentrated
8. 8
   Sonstigeto obtain an oil
9. 9
   SonstigeThe oil was triturated with hexane (200 mL) and benzene (20 mL)
10. 10
    SonstigeThe precipitate was collected
11. 11
    Sonstigedried in vacuo

Vorschrift

A solution of oxindole (25 g, 0.19 mol) in anhydrous tetrahydrofuran (800 mL) was cooled to −20° C., then n-butyllithium (2.5M in hexanes, 152 mL, 0.38 mol) was added slowly followed by N,N,N′,N′-tetramethylethylenediamine (51 mL, 0.38 mol,). After 15 min. 1,5-diiodopentane (174 g, 0.54 mol) was added slowly and the mixture was allowed to warm to room temperature. After stirring for 16 h saturated aqueous ammonium chloride solution (1L) and EtOAc (1L) were added. After 15 min. the layers were separated and the aqueous phase was extracted using EtOAc (×2). The combined organic layers were extracted with hydrochloric acid (1N), then washed with brine (500 mL), dried (MgSO4), and concentrated to obtain an oil. The oil was triturated with hexane (200 mL) and benzene (20 mL). The precipitate was collected and dried in vacuo to obtain spiro[cyclohexane-1,3′-[3H]indol]-2′-(1′H)one (26.3 g, 69.6%) as colorless crystals: mp 110-114° C.; 1H NMR (DMSO-d6) δ 1.67 (m, 10H), 6.84 (d, 1H, J=8 Hz) 6.94 (t, 1H, J=8 Hz), 7.17 (t, 1H, J=8 Hz), 7.44 (d, 1H, J=8 Hz), 10.3 (s, 1H).

Quelle