Hydrochloric Acid → HCID 15550225, compound

Participants

Reaction Steps

2-Nitro-4-methoxyaniline (16.8 g) was added to water (30 ml) and concentrated hydrochloric acid (160 ml), and stirred at room temperature for 20 minutes and then at 70° C. for 75 minutes. The reaction mixture was cooled with ice and an aqueous solution (30 ml) of sodium nitrite (11.5 g) was dropwise added so that the temperature of the reaction solution did not exceed 5° C. After addition, the mixture was stirred for 1 hour while the temperature was maintained at 10° C. The reaction mixture was filtered and the residue was washed with water (50 ml). The filtrate was cooled with ice, to which an aqueous solution (120 ml) of sodium hydrogencarbonate (123 g) and 1,4-benzoquinone (12.3 g) was dropwise added over 1 hour. After addition, the reaction mixture was stirred for 4 hours while ice cooling and then filtered. The crystal was washed with water and dried. The resulting crystal was dissolved in methanol (200 ml) and acetic acid (20 ml), and 10% palladium/carbon (1.0 g) was added thereto and stirred under a hydrogen atmosphere at room temperature for 3 hours. The reaction mixture was filtered and the residue was washed with methanol (30 ml). Under ice cooling, concentrated aqueous ammonia (50 ml) was dropwise added to the filtrate over 5 minutes. After addition, the mixture was allowed to warm to room temperature and stirred for 12 hours. The reaction mixture was filtered and the crystal was washed with water and dried in vacuo. The resulting crude product was purified by silica gel column chromatography (hexane/ethyl acetate=3/1 to 0/1) to yield the titled compound (2.71 g).

Provenance & Evidence