1-Propanol → 1H-Pyrrolo[2,3-b]pyridine-3-carboxylic acid, 1-(1,1-dimethylethyl)-5-nitro-, propyl ester

Participants

Reaction Steps

To a suspension of 5.0 g (20.47 mmol) of 1-tert-butyl-5-nitro-1H-pyrrolo[2,3-b]pyridine-3-carbonitrile in 125 mL of n-propanol, 7.78 g of p-toluensulfonic acid were added under stirring. The mixture was heated at reflux for 40 hours and then it was cooled to room temperature and diluted with 70 mL of tert-butyl methyl ether. The precipitate was filtered off and the clear filtrate was concentrated under vacuum to a small volume (about 40-50 mL). The suspension was cooled to −5/0° C. and kept at this temperature for 2 hours. The solid was filtered, washed with 20 mL of 1:1 mixture of n-propanol and tert-butyl methyl ether and dried to afford 5.50 g of the title compound as a cream-colored solid.

Provenance & Evidence