Yield:17231-50-4 85%

Reaction Conditions:

with copper(l) iodide;tetrakis(triphenylphosphine) palladium⁽⁰⁾ in N,N-dimethyl-formamide at 120; for 10 h;Inert atmosphere;Temperature;

Steps:

Preparation of 6-chloro-3-aminopyrazine-2-carbonitrile (19a)

The suspension of 18a (3 g, 14.5 mmol), NaCN (0.85 g, 17.4 mmol), CuI (1.3 g, 7.3 mmol) and Pd(PPh3)4 (0.17 g, 0.15 mmol) were stirred in DMF (40 mL) at 120 °C for 10 h under nitrogen protection. After cooling to room temperature, 10% aqueous solution of Na2S2O3(10 mL), water (60 mL) and ethyl acetate (200 mL) were added. The resulting mixture was stirred for 10 min, then filtered, and the filter cake was washed with ethyl acetate (150 mL). The organic layer was separated, washed with water (3 × 50 mL),dried over anhydrous Na2SO4and concentrated. The residue was purified by chromatography on silica gel eluting with PE/EA (10:1-2:1) to give a light-yellow solid (1.9 g, yield 85%). 6-Chloro-3-aminopyrazine-2-carbonitrile (19a) Yield: 85%, light-yellow solid, M.p.: 156-158 °C. 1H NMR(400 MHz, CDCl3):δ 8.23 (s, 1H), 5.34 (s, 2H). 13C NMR(100 MHz, CDCl3):δ 154.98, 146.84, 137.41, 114.07,111.16. EI-MS m/z: 154 (M+, Cl35,100), 156 (M+, Cl37,35),127 (M+, Cl35,-H, -CN, 48), 129 (M+, Cl37,-H, -CN, 15).

References:

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