dissolved in methanol water mixture 1 1 potassium hydroxide 3 eq was added and the mixture was heated at reflux overnight after cooling down the mixture was acidified until ph 3 by hydrochloric acid 3n the precipitate was filtered off washed with water then diethyl ether and dried under vacuum a brownish solid 5 nitro 1h pyrrolo 2 3 b pyridine 2 carboxylic acid is obtained 5 47 g yield 98 esi ms m z 208 m h hplc purity 100 step 2 general protocol for the preparation of 5 nitro 1h pyrrolo 2 3 b pyridine 2 carboxylic acid methylamide 5 nitro 1h pyrrolo 2 3 b pyridine 2 carboxylic acid 1 3 g 6 5 mmoles hatu 1 2 eq and diea 5 eq were dissolved in dry dmf under argon after stirring at rt for 15 minutes methylamine hydrochloride 3 eq was added and the mixture was allowed to stir at rt overnight the mixture was concentrated and washed by a saturated solution of sodium carbonate the precipitate was filtered off washed with water and diethyl ether to obtain a brownish solid 1 1 g 5 mmoles yield 77 esi ms m z 221 m h hplc purity 98 5 nitro 1h pyrrolo 2 3 b pyridine 2 substituted derivative was dissolved in methanol introduced in a reactor with 10 pd c and stirred for 16 hours under 35 bar of hydrogen reaction mixture was then filtered on celite and concentrated to afford the desired compound 5 amino 1h pyrrolo 2 3 b pyridine 2 substituted derivative and nitrobenzaldehyde derivative 1 eq were stirred in acoh 10 in meoh for 2 h then nabh 3 cn 2 eq was slowly added and.