Réaction #499573

Équation de réaction

1,5-diiodopentane

oxindole

n-butyllithium

ammonium chloride

N,N,N′,N′-tetramethylethylenediamine

→

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

Rendement 69.6%

Solvants

tetrahydrofuran

EtOAc

Conditions de réaction

Traitement

1. 1
   workup.ADDITIONwere added
2. 2
   AutreAfter 15 min. the layers were separated
3. 3
   Extractionthe aqueous phase was extracted
4. 4
   ExtractionThe combined organic layers were extracted with hydrochloric acid (1N)
5. 5
   Lavagewashed with brine (500 mL)
6. 6
   Séchagedried (MgSO4)
7. 7
   Concentrationconcentrated
8. 8
   Autreto obtain an oil
9. 9
   AutreThe oil was triturated with hexane (200 mL) and benzene (20 mL)
10. 10
    AutreThe precipitate was collected
11. 11
    Autredried in vacuo

Mode opératoire

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).

Source