The synthesis of Avatrombopag maleate is as follows:
A mixture containing 80.1 g of 1-(3-chloro-5-{[4-(4-chlorothiophen-2-yl)-5-(4-cyclohexyl piperazin-1-yl) thiazol-2-yl] carbamoyl} pyridin-2-yl) piperidine-4-carboxylic acid, 580 mL of DMSO, 580 mL of acetone, 17.2 g of maleic acid, and 290 mL of water was stirred at 69 °C. The insoluble matter was filtered out, washed with a mixture of 32 mL of DMSO, 32 mL of acetone, and 16 mL of water, and then the filtrate was cooled and the precipitate was collected by filtering. Washing was successively performed using 150 mL of water, 80 mL of acetone, 650 mL of water, and 80 mL of acetone, followed by drying, to obtain 70.66 g of Avatrombopag maleate.
