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

Temperature

0 °C

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)−.

1. additionwhile adding
2. customshould keep between −5-0° C.
3. additionAfter addition
4. additionThe reaction mixture was poured
5. custominto crushed ice slowly
6. stirringwith stirring for 15 min
7. stirringstirred at the same temperature for 15 min
8. extractionThe solution was extracted with ethyl acetate (3×100 mL)
9. washthe combined EtOAc layer was washed with water, brine
10. dry with materialdried over sodium sulfate
11. filtrationThe solution was filtered
12. customevaporated the solvent

ORD record

ord-0290e595fcac4c8d88c6e9fecdee5f73

Source dataset

uspto-grants-2012_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08143237B2