反应详情

A vial under nitrogen atmosphere was charged with benzopyrazine-6-boronic acid hydrochloride (500 mg, 2.38 mmol), palladium (II) acetate (16 mg, 0.071 mmol), tri-1-naphthylphosphine (88 mg, 0.214 mmol), potassium phosphate tribasic (2.52 g, 11.9 mmol), and tetrahydrofuran (10 mL). Ethyl 2-bromoacetate (0.315 mL, 2.85 mmol) was then added and the reaction mixture was stirred at reflux for 6 h. Water was added and the mixture was extracted with ethyl acetate (3×). The combined organic layers were adsorbed on silica gel. Purification on silica gel with 0-100% gradient of ethyl acetate in hexane provided 96 mg of product as a dark yellow oil. 1H NMR 500 MHz (DMSO) δ 1.20 (t, 3H), 3.99 (s, 2H), 4.11 (q, 2H), 7.79 (dd, 1H), 8.01 (d, 1H), 8.06 (d, 1H), 8.94 (d, 2H); MS (m/z) 217 [M+H+]+.

1. temperatureat reflux for 6 h
2. extractionthe mixture was extracted with ethyl acetate (3×)
3. customPurification on silica gel with 0-100% gradient of ethyl acetate in hexane