Sodium Nitrite → 6,7,8,9-tetrahydro-3H-benzo[1,2-b]1,2,3-triazino[4,5-d]selenophen-4-one

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Reaction Conditions

Reaction Steps

To an ice cold (0° C.) solution of 3-amino-4,5,6,7-tetrahydrobenzo[1,2-b]selenophene-2-carboxamide (1.4 g, 5.73 mmol) in concentrated sulfuric acid (10 mL) was added a cold (0° C.) solution of sodium nitrite (0.43 g, 6.31 mmol) in concentrated sulfuric acid (3 mL) for 10 min (while adding, the temperature should keep between −5-0° C.). After addition, the mixture was stirred at 0° C. for 2 h. The reaction mixture was poured into crushed ice slowly with stirring for 15 min and stirred at the same temperature for 15 min. The solution was extracted with ethyl acetate (3×100 mL) and the combined EtOAc layer was washed with water, brine and dried over sodium sulfate. The solution was filtered and evaporated the solvent to give the product as a pale brown color solid (450 mg, 31%), mp 150-152° C. 1H NMR (400 MHz, DMSO-d6): δ 15.13 (1H, br s, —NH), 3.01-3.04 (2H, m, H-9), 2.90-2.92 (2H, m, H-6), 1.89-1.96 (4H, m, H-7,8); LC-MS (negative ion mode): m/z 252, 254 (M−H)−.

Provenance & Evidence