3-(2-dimethylamino-ethyl)-1H-indole-5-carbaldehyde → 3-[2-(N,N-Dimethylamino)ethyl]-5-vinyl-1H-indole

HRID 71039Notes

Reaction equation

HRID 71039 reaction equation
[CH3:1][N:2]([CH3:16])[CH2:3][CH2:4][C:5]1[C:13]2[C:8](=[CH:9][CH:10]=[C:11]([CH:14]=O)[CH:12]=2)[NH:7][CH:6]=1.[CH3:17]C(C)([O-])C.[K+]>C1COCC1.[Br-].C[P+](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1>[CH3:1][N:2]([CH3:16])[CH2:3][CH2:4][C:5]1[C:13]2[C:8](=[CH:9][CH:10]=[C:11]([CH:14]=[CH2:17])[CH:12]=2)[NH:7][CH:6]=1

Participants

5

Reactant 2

HCID 99908943-(2-dimethylamino-ethyl)-1H-indole-5-carbaldehydeHCID 23665647Potassium tert-butoxide

Product 1

HCID 104432413-[2-(N,N-Dimethylamino)ethyl]-5-vinyl-1H-indoleYield 88.7%

Reagents, catalysts & solvents 2

HCID 74505Methyltriphenyliphosphonium bromideCatalystHCID 8028TetrahydrofuranSolvent

Procedure

To a solution of 3-(2-dimethylamino-ethyl)-1H-indole-5-carbaldehyde (Example 13) (0.216 g, 1 mmol) in THF (5 mL), methyl triphenyl phosphonium bromide (0.393 g, 1.1 mmol) is added. To the obtained slurry, under an argon atmosphere potassium tert-butoxide (0.118 g, 1.05 mmol) is added in three portions at ambient temperature. When thin layer chromatography (TLC) indicates complete conversion of the aldehyde, the mixture is poured on ice and extracted with ethyl acetate. Removal of the solvent gives a residue which is chromatographed on silica (25 g, CHCl3, MeOH, NEt3 19:1:0.5 v:v:v) to give the title product as pale yellow oil (0.190 g, 88%). 1H-NMR (CDCl3, 300 MHz) δ 2.37 (s, 6H, N(CH3)2); 2.64-2.70 (m, 2H, CH2NMe2); 2.92-2.99 (m, 2H, CH2); 5.13 (d, 1H, J=10.9 Hz, cis H2C═CH); 5.69 (d, 1H, J=17.6 Hz, trans H2C═CH); 6.84 (dd, 1H, H2C═CH); 6.94 (br s, 1H, H-2); 7.24 (d, 1H, J=8.2 Hz, H-7); 7.31 (dd, J=1.8 Hz, H-6); 7.58 (d, 1H, H-4); 8.66 (br s, 1H, NH). 13C-NMR (CDCl3, 75 MHz) δ 24.00 (CH2); 45.73 (N(CH3)2); 60.62 (CH2NMe2); 110.93 (H2C═CH); 111.50 (C-7); 114.66 (C-3); 117.41 (C-4); 120.20 (C-6); 122.42 (C-2); 127.83 (C-5); 129.34 (C-9); 136.45 (C-8); 138.22 (H2C═CH).

Workup

  1. additionthe mixture is poured on ice
  2. extractionextracted with ethyl acetate
  3. customRemoval of the solvent
  4. customgives a residue which
  5. customis chromatographed on silica (25 g, CHCl3, MeOH, NEt3 19:1:0.5 v:v:v)

Sources & evidence

ORD record
ord-fc1974ae3ec64dd49a5ce6553fb3cee2
Source dataset
uspto-grants-2014_09
Patent number
US08822702B2

Reaction notes

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