反应详情

To a mixture of 10 g of methyl 3-chloro-2-hydrazino-7-methylquinoxaline-6-carboxylate, 5.9 g of tetrahydro-2H-pyran-4-carboxylic acid, 16 mL of triethylamine, and 100 mL of dichloromethane was added 21 g of bromo(tripyrrolidin-1-yl)phosphonium hexafluorophosphate, followed by stirring at room temperature for 9 hours. To the reaction mixture were added saturated aqueous sodium hydrogen carbonate solution and chloroform. The solid was collected by filtration and washed with ethyl acetate to obtain 9.1 g of methyl 3-chloro-7-methyl-2-[2-(tetrahydro-2H-pyran-4-ylcarbonyl)hydrazino]quinoxaline-6-carboxylate as a pink solid. Further, to the filtrate obtained above was added chloroform, and then the aqueous layer was separated. The organic layer was washed with saturated brine and dried over anhydrous magnesium sulfate. The solvent was evaporated under reduced pressure and the obtained residue was washed with ethyl acetate to obtain 3.58 g of methyl 3-chloro-7-methyl-2-[2-(tetrahydro-2H-pyran-4-ylcarbonyl)hydrazino]quinoxaline-6-carboxylate as a colorless solid.

1. filtrationThe solid was collected by filtration
2. washwashed with ethyl acetate