Bromoform → 2-Bromo-5,8-dimethyl-[1,2,4]triazolo[1,5-a]pyrazine

Temperature

25 °C

A mixture of 5,8-dimethyl-[1,2,4]triazolo[1,5-a]pyrazin-2-ylamine (2.4 g, 14.71 mmol), sodium nitrite (10.15 g, 147.08 mmol) and benzyltriethylammonium bromide (8 g, 29.42 mmol) in bromoform (76.2 ml, 872.17 mmol) was stirred at 25° C. for 30 minutes. To this mixture was then added dichloroacetic acid (2.43 ml, 29.42 mmol) and the reaction mixture was stirred at 25° C. for further 20 hours. (The reaction flask was wrapped in aluminum foil to protect the mixture from light). Water (100 ml) was added to the reaction mixture, which was then stirred for 30 minutes at 25° C., and finally extracted 4 times with dichloromethane. The combined organic layers were washed twice with water and brine, dried over anhydrous sodium sulfate, filtered and evaporated. The crude material thus obtained was purified by silica gel column chromatography using hexane ethyl acetate 20% as eluent affording 2-bromo-5,8-dimethyl-[1,2,4]triazolo[1,5-a]pyrazine (4.8 g, 74.72%) as an off white solid. MS: m/z=227 (M+H+)

1. stirringwas then stirred for 30 minutes at 25° C.
2. extractionfinally extracted 4 times with dichloromethane
3. washThe combined organic layers were washed twice with water and brine
4. dry with materialdried over anhydrous sodium sulfate
5. filtrationfiltered
6. customevaporated
7. customThe crude material thus obtained
8. customwas purified by silica gel column chromatography

ORD record

ord-c67e631293d74f34a923ee368255f971

Source dataset

uspto-grants-2016_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09394311B2