Water → 1',2'-Dihydrospiro[cyclopentane-1,3'-indole]-2'-one

HRID 1060038Notes

Reaction equation

HRID 1060038 reaction equation
[NH:1]1[C:9]2[C:4](=[CH:5][CH:6]=[CH:7][CH:8]=2)[CH2:3][C:2]1=[O:10].[CH2:11]([Li])[CH2:12][CH2:13][CH3:14].ICCCCI.O>C1COCC1>[NH:1]1[C:9]2[C:4](=[CH:5][CH:6]=[CH:7][CH:8]=2)[C:3]2([CH2:14][CH2:13][CH2:12][CH2:11]2)[C:2]1=[O:10]

Participants

6

Reactant 4

HCID 962WaterHCID 123371,4-DiiodobutaneHCID 321710OxindoleHCID 178418339Butyllithium

Product 1

HCID 3633431',2'-Dihydrospiro[cyclopentane-1,3'-indole]-2'-oneYield 50%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

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′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), the combined organic layers were washed with dilute HCl (pH 1) and 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) δ1.8-2.2 (m, 8H), 6.94 (dd, J=7.5, 1.0 Hz, 1H), 7.01 (dd, J7.5, 1.0Hz, 1H), 7.14-7.25 (m, 2H), 9.30 (br s, 1H).

Workup

  1. extractionextracted with EtOAc (×2)
  2. washthe combined organic layers were washed with dilute HCl (pH 1) and water (×2)
  3. dry with materialdried (MgSO4)
  4. customevaporated
  5. customThe residue was purified by column chromatography (SiO2, EtOAc: hexane 1:4)

Sources & evidence

ORD record
ord-8bc74f1776da41539e078b9314f3120d
Source dataset
uspto-grants-2003_02
Patent number
US06521657B2

Reaction notes

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