2-(Ethoxycarbonyl)-1H-indole-5-carboxylic acid → diethyl 1H-indole-2,5-dicarboxylate

HRID 1829968Notes

Reaction equation

HRID 1829968 reaction equation
[CH3:1][CH2:2][O:3][C:4]([C:6]1[NH:7][C:8]2[C:13]([CH:14]=1)=[CH:12][C:11]([C:15]([OH:17])=[O:16])=[CH:10][CH:9]=2)=[O:5].Cl.[CH3:19][CH2:20]O>>[CH2:2]([O:3][C:4]([C:6]1[NH:7][C:8]2[C:13]([CH:14]=1)=[CH:12][C:11]([C:15]([O:17][CH2:19][CH3:20])=[O:16])=[CH:10][CH:9]=2)=[O:5])[CH3:1]

Participants

3

Reactant 2

HCID 180713652-(Ethoxycarbonyl)-1H-indole-5-carboxylic acidHCID 21887872Ethanol hydrochloride

Product 1

HCID 15629756diethyl 1H-indole-2,5-dicarboxylateYield 99%

Conditions

Temperature
55 °C

Procedure

A suspension of 1H-Indole-2,5-dicarboxylic acid 2-ethyl ester (20.0 g, 85.75 mmole) in a saturated HCl/EtOH (200 ml) was stirred at 55° C. for 24 h and evaporated in vacuo to dryness. The residue was freeze-dried from dioxane to give 22.18 g (99%) of 1H-indole-2,5-dicarboxylic acid diethyl ester, 16 as white powder. MS: 262.12 (M+H). 1H-NMR (DMSO-d6): δ 12.23 (s, 1H, H-1, indole); 8.34 (m, 1H, H-4, indole); 7.83 (m, 1H, H-6, indole); 7.49 (m, 1H, H-7, indole); 7.30 (s, 1H, H-3, indole); 4.31 (m, 4H, —OCH2CH3); 1.32 (m, 4H, —OCH2CH3).

Workup

  1. customevaporated in vacuo to dryness
  2. dry with materialThe residue was freeze-dried from dioxane

Sources & evidence

ORD record
ord-164cec0e7d3a4c4bb689afad7f216994
Source dataset
uspto-grants-2006_06
Patent number
US07064218B2

Reaction notes

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