tert-Butyl 3-bromo-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazine-7(8H)-carboxylate

Chemical Properties

White solid

Synthesis

The general procedure for the synthesis of 7-Boc-3-bromo-5,6,7,8-tetrahydro-1,2,4-triazolo[4,3-a]pyrazine using 7-Boc-5,6,7,8-tetrahydro-1,2,4-triazolo[4,3-a]pyrazine as a starting material was as follows: 7-Boc-5,6,7,8-tetrahydro-1,2,4-triazolo[4,3-a]pyrazine (1 g ) was dissolved in chloroform (20 mL) and sodium bicarbonate (688 mg) and N-bromosuccinimide (873 mg) were added sequentially at 0 °C in an ice bath. The reaction mixture was stirred at 0 °C for 2 hours. Upon completion of the reaction, the reaction solution was brought back to room temperature and the reaction was quenched by the addition of an appropriate amount of water, followed by three extractions with chloroform. The organic layers were combined, dried with anhydrous sodium sulfate, filtered and concentrated under reduced pressure to give the crude product. The crude product was purified by silica gel column chromatography to afford the target compound 7-Boc-3-bromo-5,6,7,8-tetrahydro-1,2,4-triazolo[4,3-a]pyrazine (693 mg, 51% yield). lRMS (ESI) m/z 303 [M+H]+.

References

[1] Patent: JP5851663, 2016, B1. Location in patent: Paragraph 0303
[2] Patent: WO2004/58266, 2004, A1. Location in patent: Page/Page column 80