Yield: 87.8%

Reaction Conditions:

with toluene-4-sulfonic acid;trifluoroacetic anhydride in toluene at 90; for 48 h;Industrial scale;Reagent/catalyst;Solvent;Temperature;

Steps:

1.S3; 2.S3; 3.S3; 4.S3 The third step: Preparation of 2-(trifluoromethyl)-[1,2,4]triazolo[1,5-α]pyrazine
Combine 2,2,2-trifluoro-N'-hydroxy-N-pyrazin-2-yl acetimidamide (2.06kg, 10mol), toluene (10L),A mixture of 4-toluenesulfonyl chloride (2.10kg, 11mol) and trifluoroacetic anhydride (10.5kg, 50mol) was heated to 90°C and stirred for 48 hours.After concentration under reduced pressure, the pH was adjusted to 8 with aqueous sodium bicarbonate solution, and the remaining mixture was extracted three times with ethyl acetate.Concentrate to dryness, then dissolve in 1.5L ethyl acetate, slowly add 10L n-hexane,A solid precipitated out and filtered to obtain 1.65 kg of a yellow solid (molar yield 87.8%),

References:

Shanghai Zaiqi Biological Co., Ltd.;Sun Peng;Shi Lei;Wu Baoping;Tian Beibei;Bian Yicheng;Yang Hongxia;Zhang Xin CN111635407, 2020, A Location in patent:Paragraph 0031-0032; 0037-0041; 0046-0050; 0054-0058; 0063