Triethyl orthoacetate → 1-Ethyl-2-methyl-1H-benzoimidazole-5-carboxylic acid

HRID 1591970Notes

Reaction equation

HRID 1591970 reaction equation
[NH2:1][C:2]1[CH:3]=[C:4]([CH:8]=[CH:9][C:10]=1[NH:11][CH2:12][CH3:13])[C:5]([OH:7])=[O:6].[C:14](OCC)(OCC)(OCC)[CH3:15]>CCO>[CH2:12]([N:11]1[C:10]2[CH:9]=[CH:8][C:4]([C:5]([OH:7])=[O:6])=[CH:3][C:2]=2[N:1]=[C:14]1[CH3:15])[CH3:13]

Participants

4

Reactant 2

HCID 66221Triethyl orthoacetateHCID 8544283-amino-4-ethylamino-benzoic Acid

Product 1

HCID 8244051-Ethyl-2-methyl-1H-benzoimidazole-5-carboxylic acid

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A mixture of 1.4 g (7.7 mmol) of the title B compound, 3-amino-4-ethylamino-benzoic acid and 15 mL (104 mmol) of triethyl orthoacetate in 20 mL of EtOH is refluxed for 7 h. The reaction mixture is allowed to cool to RT and the precipitated solid is collected by filtration, washed with EtOH (2×), then with methyl-t-butylether (MTBE) and dried in vacuo to give 1-ethyl-2-methyl-1H-benzoimidazole-5-carboxylic acid as a grey solid: mp>250° C.; 1H-NMR (DMSO-d6) δ 12.65 (s, 1H), 8.11 (s, 1H), 7.82 (dd, 1H), 7.59 (d, J=8.46, 1H), 4.26 (q, 2H), 2.57 (s, 3H), 1.30 (t, 3H); [M−1]−=203.

Workup

  1. temperatureis refluxed for 7 h
  2. filtrationthe precipitated solid is collected by filtration
  3. washwashed with EtOH (2×)
  4. dry with materialwith methyl-t-butylether (MTBE) and dried in vacuo

Sources & evidence

ORD record
ord-5cdeca51c3b1431e8a2288e614b03bbb
Source dataset
uspto-grants-2007_11
Patent number
US07291635B2

Reaction notes

Loading…