3-a]pyrazine synthesis

Yield:-

Reaction Conditions:

with acetic acid for 1 h;Reflux;

Steps:

30.3 Step 3: Preparation of 5-chloro-[1 ,2,4]triazolo[4,3-a]pyrazine

A solution of N'-[(6-chloropyrazin-2-yl)amino]-N,N-dimethyl-formamidine (2 g) in acetic acid (20 mL) was heated at reflux for 1 hour. The reaction mass was concentrated and partitioned between saturated aqueous sodium carbonate and ethyl acetate. The organic layer was dried over sodium sulfate, concentrated and the resulting residue was triturated with methyl t-butyl ether to give 5-chloro- [1 ,2,4]triazolo[4,3-a]pyrazine. ¹H NMR (400 MHz, DMSO-d₆) 9.69 (s, 1 H), 9.45 (s, 1 H), 8.17 (s, 1 H)

References:

WO2021/58595,2021,A1 Location in patent:Page/Page column 104-105