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ChemicalBook CAS DataBase List 2-Amino-5-chloropyrazine
33332-29-5

2-Amino-5-chloropyrazine synthesis

5synthesis methods
-

Yield:33332-29-5 80%

Reaction Conditions:

with N-chloro-N-methoxy-4-methylbenzenesulfonamide in acetonitrile at 40; for 4 h;Reagent/catalyst;Temperature;

Steps:

Preparation of 2-amino-5-chloropyrazine (17)
Method B. To a suspension of 2-aminopyrazine (3 g, 31.6 mmol) in acetonitrile (50 mL) was added N-chloro-N-methoxy-4-methylbenzenesulfonamide (TSA, 8.2 g,34.7 mmol) in batches at room temperature. The reaction mixture was heated at 40 °C for 4 h. Subsequently, the solvent was evaporated in vacuum and the residue was partitioned between ethyl acetate (50 mL) and saturated aqueous Na2CO3solution (20 mL). The organic layer was dried over anhydrous Na2SO4,decolorized with activated charcoal (0.8 g), and concentrated. The crude product containing ~ 5% dichlorinated impurity judged by TLC was purified by chromatography on silica gel eluting with PE/EA (10:1-2:1) to give a light-yellow solid (3.3 g, yield 80%).

References:

Guo, Qi;Xu, Mingshuo;Guo, Shuang;Zhu, Fuqiang;Xie, Yuanchao;Shen, Jingshan [Chemical Papers,2019,vol. 73,# 5,p. 1043 - 1051]

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