Ethyl orthoformate → 5-Bromo-8-methoxy-[1,2,4]triazolo[4,3-A]pyrazine
Reaction equation
[Br:1][C:2]1[N:3]=[C:4]([NH:10][NH2:11])[C:5]([O:8][CH3:9])=[N:6][CH:7]=1.[CH:12](OCC)(OCC)OCC>>[Br:1][C:2]1[N:3]2[CH:12]=[N:11][N:10]=[C:4]2[C:5]([O:8][CH3:9])=[N:6][CH:7]=1Participants
3
Conditions
- Temperature
- 130 °C
Procedure
A 100 mL round bottom flask was charged with 5-bromo-3-hydrazinyl-2-methoxypyrazine (0.5 g crude, ˜1.9 mmol) and triethyl orthoformate (5 mL). The resulting mixture was heated at 130° C. overnight. TLC indicated a complete conversion. Work-up: the reaction mixture was concentrated. The residue was purified by flash column chromatography on silica gel with a 1:50 methanol/dichloromethane, to afford 0.28 g (66% for 2 steps) of the product as a pale yellow solid. 1H NMR (300 MHz, CDCl3) δ: 8.93 (s, 1H), 7.47 (s, 1H), 4.18 (s, 3H). MS m/z: 229 (M+H+).
Workup
- concentrationthe reaction mixture was concentrated
- customThe residue was purified by flash column chromatography on silica gel with a 1:50 methanol/dichloromethane
Sources & evidence
- ORD record
- ord-362e442d1b174f2c8bb5a32d84c7f6e0
- Source dataset
- uspto-grants-2013_10
- Patent number
- US08569300B2
Reaction notes
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