2-chloro-6-ethynylpyrazine synthesis

Yield:1196157-03-5 16%

Reaction Conditions:

with potassium carbonate in methanol at 0; for 6 h;

Steps:

6

Preparation of compound 6b: 2-Chloro-6-ethynylpyrazine A solution of 6a (861 mg, 4.09 mmol) in MeOH (10 ml_) was cooled to 0 ⁰C treated with potassium carbonate (565 mg, 4.09 mmol). The reaction mixture was stirred at 0 ⁰C for 6 h. The reaction mixture was filtered and the solids washed with methanol. The filtrate was concentrated under reduced pressure. The resultant solid dissolved in ethyl acetate and washed with water, brine, dried over Na₂SO₄, decanted and concentrated under reduced pressure. The crude product was purified by flash chromatography on silica gel (0-20% EtOAc-hexanes) which gave the title compound 6b as a tan solid (91 mg, 16% yield). 1 H NMR (400 MHz, MeOD) δ ppm 8.66 (s, 1 H), 8.64 (s, 1 H), 4.12 (s, 1 H).

References:

WO2010/16005,2010,A1 Location in patent:Page/Page column 86-87