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HuagongsheHuagongshe Chemistry Print Report · For research reference only
HRID 2200318Generated: October 30, 2026

Phosphoric Acid → 7-bromo-1-ethyl-3,4-dihydropyrazino[2,3-b]pyrazin-2(1H)-one

https://huagongshe.com/reaction/2200318

Reaction equation

Participants

RoleNameHCIDCharge
ReactantPhosphoric AcidHCID 1004—
ReactantEthylamineHCID 6341—
ReactantHCID 86654274HCID 86654274—
SolventWaterHCID 962—
Product7-bromo-1-ethyl-3,4-dihydropyrazino[2,3-b]pyrazin-2(1H)-oneHCID 86654275—

Reaction Conditions

Temperature90 °C

Reaction Steps

The 2-((3,5-dibromopyrazin-2-yl)amino)acetic acid and ethylamine (4 equiv, 70 wt % solution) were combined in water and the mixture was stirred at 90° C. The reaction mixture was cooled to 80° C. and treated with phosphoric acid (4 equiv), and the mixture was cooled to room temperature and the solids were collected by filtration. The product was dried to obtain 7-bromo-1-ethyl-3,4-dihydropyrazino[2,3-b]pyrazin-2(1H)-one as a solid. MS (ESI) m/z 256.9

Provenance & Evidence

DOI10.6084/m9.figshare.5104873.v1
Patent numberUS09359364B2
Source datasetuspto-grants-2016_06
ORD IDord-26f8eea241ad4bcaa31c057b6ab5b856
Source noteuspto-grants-2016_06