800401-68-7

5-Chloro-1H-pyrrolo[2,3-c]pyridine-2-carboxylic Acid is a useful reactant for preparation of pyrrolopyridinecarboxylic acid amide as inhibitors of glycogen phosphorylase.

GENERAL METHOD: To a stirred solution of ethyl 5-chloro-1H-pyrrolo[2,3-c]pyridine-2-carboxylate (1.3 mmol) in ethanol (12 mL) was added 2 M sodium hydroxide solution (1.7 mmol, 1.1 mL). The reaction mixture was heated to reflux for 1 h (for the synthesis of 5-chloro-6-azaindole-2-carboxylic acid) or 2 h (for the synthesis of other derivatives). After evaporation to remove the solvent, water (10 mL) was added and the pH was adjusted with acetic acid to 4.0. The precipitate was collected by filtration and the resulting solid was dried in a desiccator to give the target product 5-chloro-6-azaindole-2-carboxylic acid.

[1] Molecules, 2014, vol. 19, # 9, p. 13342 - 13357
[2] Patent: WO2006/59164, 2006, A2. Location in patent: Page/Page column 20-21
[3] Patent: WO2006/67532, 2006, A1. Location in patent: Page/Page column 19
[4] Patent: WO2005/85245, 2005, A1. Location in patent: Page/Page column 18
[5] Patent: WO2004/104001, 2004, A2. Location in patent: Page 35-36