Ethanol → 3-(2-Carboxyethyl)-4,6-dibromo-1H-indole-2-carboxylic acid

HRID 467423Notes

Reaction equation

HRID 467423 reaction equation
[Br:1][C:2]1[CH:10]=[C:9]([Br:11])[CH:8]=[C:7]2[C:3]=1[C:4]([CH2:17][CH2:18][C:19]([O:21]CC)=[O:20])=[C:5]([C:12]([O:14]CC)=[O:13])[NH:6]2.O.O.O.[OH-].[Li+].C(O)C.C(OCC)(=O)C>O1CCCC1.O.CO.CCCCCC>[C:19]([CH2:18][CH2:17][C:4]1[C:3]2[C:7](=[CH:8][C:9]([Br:11])=[CH:10][C:2]=2[Br:1])[NH:6][C:5]=1[C:12]([OH:14])=[O:13])([OH:21])=[O:20]

Participants

9

Reactant 4

HCID 702EthanolHCID 8857Ethyl AcetateHCID 71280731ethyl 4,6-dibromo-3-(3-ethoxy-3-oxopropyl)-1H-indole-2-carboxylateHCID 86677587Lithium hydroxide trihydrate

Product 1

HCID 712808663-(2-Carboxyethyl)-4,6-dibromo-1H-indole-2-carboxylic acidYield 95%

Reagents, catalysts & solvents 4

HCID 887MethanolSolventHCID 962WaterSolvent2×HCID 8028TetrahydrofuranSolvent2×HCID 8058HexaneSolvent

Procedure

Ethyl 4,6-dibromo-3-(3-ethoxy-3-oxopropyl)-1H-indole-2-carboxylate (4.47 g, 10 mmol) was dissolved in 25 ml tetrahydrofurane (THF) with stirring at rt. Then a solution of 1.26 g of lithium hydroxide trihydrate (3 equiv.) in 25 ml water was added and the resulting mixture was let to stir at rt for 24 h. After completion of the reaction THF was removed under reduced pressure and the pH was adjusted to 4-5, and the product was extracted with diethyl ether (3×30 ml). The organic layers were dried over magnesium sulfate, filtered, and evaporated to dryness to yield a light-beige-colored solid in 95-100% yield. mp. 259° C.; well soluble in methanol, ethanol and ethyl acetate; slightly soluble in petrol ether, water, hexane. 1H-NMR (MeOH-d4): δ 2.67 (t, 2H, 3J=8.4 Hz, CH2); 3.71 (t, 2H, 3J=8.4 Hz, CH2); 7.42 (d, 1H, 4J=1.6 Hz, C7-H); 7.62 (d, 1H, 4J=1.6 Hz, C5-H). 13C-NMR (MeOH-d4): δ 21.4 (C-2′); 37.9 (C-1′); 115.9 (C-7); 117.0 (C-4); 118.8 (C-6); 123.9 (C-3); 125.5 (C-2); 127.9 (C-3a); 128.2 (C-5); 139.6 (C-7a); 164.6 (2′-CO2H); 170.1 (2-CO2H). LC-MS (m/z): 392.0 [M]+; 390.0 [M]−. Purity (LC-MS): 99%.

Workup

  1. stirringto stir at rt for 24 h
  2. customwas removed under reduced pressure
  3. extractionthe product was extracted with diethyl ether (3×30 ml)
  4. dry with materialThe organic layers were dried over magnesium sulfate
  5. filtrationfiltered
  6. customevaporated to dryness
  7. customto yield a light-beige-colored solid in 95-100% yield

Sources & evidence

ORD record
ord-4bbe4df48bca493f912df48a110b19c7
Source dataset
uspto-grants-2014_01
Patent number
US08623593B1

Reaction notes

Loading…