Nitric Acid → 1-[5-Nitro-2-(4-pyridinylamino)benzoyl]piperidine

Participants

Reaction Conditions

Reaction Steps

To a solution of 20 g of 1-[2-(4-pyridinylamino)benzoyl]piperidine (Example 1b) in 75 ml of sulfuric acid cooled in an ice-salt bath was slowly added a solution of 6.5 ml of concentrated nitric acid in 65 ml of sulfuric acid. The mixture was stirred at 5° C. for four hours and then poured onto ice and allowed to stand overnight. A crystalline acid-addition salt formed which was collected, dissolved in water and converted to the free base by adding sodium bicarbonate. The free base product was extracted with methylene dichloride, the extracts dried over anhydrous sodium sulfate and concentrated, and the residue triturated with ethyl acetate to give 9.3 g of 1-[5-nitro-2-(4-pyridinylamino)benzoyl]piperidine as a yellow powder, m.p. 194°-196° C.(decompn.).

Provenance & Evidence