Hydrochloric Acid → 2-(2-Oxo-2,3-dihydroimidazo[1,2-a]pyridin-3-yl)butanedioic acid

HRID 544708Notes

Reaction equation

HRID 544708 reaction equation
[OH-].[Na+].Cl.[N:4]1[C:5](=[O:13])[CH2:6][N:7]2[CH:12]=[CH:11][CH:10]=[CH:9][C:8]=12.[C:14]([OH:21])(=[O:20])/[CH:15]=[CH:16]\[C:17]([OH:19])=[O:18]>O>[C:17]([CH:16]([CH:6]1[N:7]2[CH:12]=[CH:11][CH:10]=[CH:9][C:8]2=[N:4][C:5]1=[O:13])[CH2:15][C:14]([OH:21])=[O:20])([OH:19])=[O:18]

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 14798Sodium HydroxideHCID 444266Maleic AcidHCID 541778Imidazo[1,2-a]pyridin-2(3H)-one

Product 1

HCID 203995172-(2-Oxo-2,3-dihydroimidazo[1,2-a]pyridin-3-yl)butanedioic acid

Reagents, catalysts & solvents 1

HCID 962WaterSolvent3×

Conditions

Temperature
5 °C

Procedure

A hot solution of 80 g (2 moles) of sodium hydroxide in 200 ml of water is added in portions, while stirring, to a mixture of 341 g (2 moles) of the hydrochloride of imidazo[1,2-a]pyridin-2(3H)-one in 700 ml of water. Then, a solution of 250.7 g (2.16 moles) of maleic acid in 600 ml of water is added dropwise in such a manner that the internal temperature of the reaction mixture remains between 40° and 45° C. After 30 hours at room temperature (20°-25° C.) the mixture is cooled to 5° C., the resulting precipitate is filtered off, the filtrate is concentrated in vacuo to approximately half its volume, and the resulting product is filtered with suction. The combined residues are washed with a little cold methanol and dried in vacuo at 50° C. 400 g of 3-(1,2-dicarboxyethyl)-imidazo[1,2-a]pyridin-2(3H)-one having a melting point of 193° (decomposition) are obtained. The resulting product is stirred at room temperature for 6 hours with 650 ml of concentrated hydrochlorid acid. After cooling to 5° C., the precipitate is filtered off, the filtrate is concentrated in vacuo to approximately half its volume and the resulting product is filtered with suction. The combined residues are washed with acetone and dried in vacuo at 50° C. In this manner the hydrochloride of 3-(1,2-dicarboxyethyl)-imidazo[1,2-a]pyridin-2(3H)-one having a melting point of 205° C. (decomposition) is obtained.

Workup

  1. customremains between 40° and 45° C
  2. filtrationthe resulting precipitate is filtered off
  3. concentrationthe filtrate is concentrated in vacuo to approximately half its volume
  4. filtrationthe resulting product is filtered with suction
  5. washThe combined residues are washed with a little cold methanol
  6. customdried in vacuo at 50° C

Sources & evidence

ORD record
ord-41674039e3464e8892422b3d250c1aa1
Source dataset
uspto-grants-1984_05
Patent number
US04451462

Reaction notes

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