Hydrochloric Acid → 4-CHLOROTHIENO[2,3-B]PYRIDINE-5-CARBOXYLIC ACID

HRID 1611486Notes

Reaction equation

HRID 1611486 reaction equation
[Cl:1][C:2]1[C:7]([C:8]([O:10]CC)=[O:9])=[CH:6][N:5]=[C:4]2[S:13][CH:14]=[CH:15][C:3]=12.[OH-].[Na+].Cl>C(O)C>[Cl:1][C:2]1[C:7]([C:8]([OH:10])=[O:9])=[CH:6][N:5]=[C:4]2[S:13][CH:14]=[CH:15][C:3]=12

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 14798Sodium HydroxideHCID 12376227Ethyl 4-chlorothieno[2,3-b]pyridine-5-carboxylate

Product 1

HCID 113563314-CHLOROTHIENO[2,3-B]PYRIDINE-5-CARBOXYLIC ACIDYield 35.4%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Conditions

Temperature
0 °C

Procedure

A mixture of ethyl 4-chlorothieno[2,3-b]pyridine-5-carboxylate (800 mg, 3.31 mmol) [Khan, M. A.; Guarconi, A. E., J. Heterocyclic Chem., 14, 807 (1977)] in 15 mL of ethanol and 5 mL of 2.5 N sodium hydroxide is heated at reflux for 90 minutes. The mixture is cooled to 0° C. and the pH is adjusted to 4 by the addition of 2 N hydrochloric acid. The mixture is stirred at room temperature and the resulting precipitate is collected by filtration and washed with water to provide 250 mg of 4-chlorothieno[2,3-b]pyridine-5-carboxylic acid as a white solid, mp 172-174° C.; 1H NMR (DMSO-d6) δ 7.62 (d, J=6 Hz, 1H), 8.14 (d, J=6 Hz, 1H), 8.94 (s, 1H); MS 212.0 (M−H)−.

Workup

  1. temperatureat reflux for 90 minutes
  2. filtrationthe resulting precipitate is collected by filtration
  3. washwashed with water

Sources & evidence

ORD record
ord-6b7afc2bfa304443b87cc228762e0e65
Source dataset
uspto-grants-2006_01
Patent number
US06987116B2

Reaction notes

Loading…