(6-METHOXYPYRAZIN-2-YL)BORONIC ACID PINACOL ACID synthesis

Yield:960503-91-7 600 mg

Reaction Conditions:

with tris-(dibenzylideneacetone)dipalladium⁽⁰⁾;potassium acetate;tricyclohexylphosphine in 1,2-dimethoxyethane at 150; for 3 h;Inert atmosphere;Microwave irradiation;

Steps:

137

Example 137
A mixture of 2-chloro-6-methoxypyrazine (500 mg, 3.46 mmol, 1.0 eq), bis(pinacolato)diboron (1.05 g, 4.13 mmol, 1.2 eq), Pd₂(dba)₃ (95 mg, 0.1 mmol, 0.029 eq), P(Cy)₃ (120 mg, 0.43 mmol, 0.13 eq), and potassium acetate (600 mg, 6.11 mmol, 1.77 eq) in 1,2-dimethoxyethane (10 mL) was irradiated under argon at 150° C. in a microwave oven for 3 h.
The mixture was allowed to cool to RT, quenched with water and extracted with ethyl acetate.
The combined organic layers were washed with brine, dried over Na₂SO₄ and filtered.
The filtrate was concentrated in vacuo to afford the pinacol ester (600 mg).

References:

US2013/53362,2013,A1 Location in patent:Paragraph 0987; 0988