Hydrochloric Acid → 7-(2-Methoxyethoxy)imidazo[1,2-a]pyridine-3-carboxylic acid

HRID 706756Notes

Reaction equation

[CH3:1][O:2][CH2:3][CH2:4][O:5][C:6]1[CH:11]=[CH:10][N:9]2[C:12]([C:15]([O:17]CC)=[O:16])=[CH:13][N:14]=[C:8]2[CH:7]=1.O1CCCC1.O.[OH-].[Li+].Cl>O.C(O)C>[CH3:1][O:2][CH2:3][CH2:4][O:5][C:6]1[CH:11]=[CH:10][N:9]2[C:12]([C:15]([OH:17])=[O:16])=[CH:13][N:14]=[C:8]2[CH:7]=1

Participants

Conditions

Temperature: 40 °C

Procedure

Ethyl 7-(2-methoxyethoxy)imidazo[1,2-a]pyridine-3-carboxylate (6.06 g; 22.9 mmol) was mixed with tetrahydrofuran (225 mL), ethanol (110 mL) and water (55 mL). Lithium hydroxide monohydrate (0.962 g; 22.9 mmol) was added. The mixture was stirred under an atmosphere of nitrogen and heated at 40° C. for 22 hours. The mixture was allowed to cool and then concentrated under reduced pressure to give a yellow gum. Water (50 mL) was added and the mixture stirred to until homogeneous. Hydrochloric acid (2N) was added with stirring to adjust to pH 3. The mixture was cooled with an ice/water bath. The resulting precipitate was collected by filtration and washed with a small amount of water (10 mL). The material was dried under vacuum to give 7-(2-methoxyethoxy)imidazo[1,2-a]pyridine-3-carboxylic acid as a white solid (4.90 g).

Workup

temperatureto cool
concentrationconcentrated under reduced pressure
customto give a yellow gum
stirringthe mixture stirred to until homogeneous
stirringwith stirring
temperatureThe mixture was cooled with an ice/water bath
filtrationThe resulting precipitate was collected by filtration
washwashed with a small amount of water (10 mL)
customThe material was dried under vacuum

Sources & evidence

ORD record: ord-b967e31ef11c4f2180cbe6e50e6a7c90
Source dataset: uspto-grants-2015_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09174981B2

Reaction notes

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