Potassium Phosphate, Tribasic → methyl 2-(3,4-dihydro-2H-benzo[b][1,4]dioxepin-7-yl)-3-(isopropyl(methyl)amino)quinoxaline-6-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of 3,4-dihydro-2H-benzo[b][1,4]dioxepin-7-ylboronic acid (200.0 mg, 1.03 mmol in dioxane (5.0 mL) was added methyl 2-chloro-3-(isopropyl(methyl)amino)quinoxaline-6-carboxylate (Scheme I, 150.0 mg, 0.52 mmol), K3PO4 (325.9 mg, 1.54 mmol) and Pd(PPh3)4 (29.7 mg, 0.03 mmol) and water (3 drops) with stirring for 1 h at 90° C. in an oil bath maintained with an inert atmosphere of nitrogen. The reaction mixture was concentrated under vacuum to give a residue, which was purified by a silica gel column with 1% ethyl acetate in petroleum ether to afford methyl 2-(3,4-dihydro-2H-benzo[b][1,4]dioxepin-7-yl)-3-(isopropyl(methyl)amino)quinoxaline-6-carboxylate as a light yellow solid (140.0 mg, 63%).

Provenance & Evidence