4-Nitrobenzoic Acid → 2-(4-Nitro-phenyl)-3H-imidazo[4,5-c]pyridine-6-ylamine

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

2,4,5 Triaminopyridine (6, 0.660 g, 5.32 mmol), p-nitro benzoic acid (7, 0.888 mg 5.32 mmol) was taken in PPA (30 g) and heated at 180° C. for 7 h. The reaction mixture was cooled to room temperature and poured on to crushed ice. The excess PPA was neutralized carefully by addition of solid K2CO3 portion wise (caution) till effervescence ceased. The brownish green precipitate was filtered and washed with water and dried. The solid was taken in (CH2Cl2: MeOH:THF:NH4OH 50:30:17:3) mixture and filtered (repeated the process 3-4 times). The solvents were removed and the nitro amine precipitated with EtOAc to give 8 (0.575 g, 56%). 1H NMR (DMSO-d6; 500 MHz): δ11.10 (1H, brs), 8.77 (1H, s), 8.45-8.25 (4H m), 6.50 (1H, s), 5.67 (2H, brs); EIMS m/z: 256.4 (M+1) and 290 (M+Cl−);

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