To a solution of 8.00 g of 4-cyano-3-fluoro-6-nitroaniline (which was synthesized following J. Med. Chem. 1994, 37, 467) and 17.60 g of 1-tert-butoxycarbonyl-3-methylpiperazine in 25 ml of dimethylsulfoxide, 23 ml of diisopropylethylamine was added and stirred for 3 hours at 140° C. and 12 hours at room temperature. 1N aqueous sodium hydroxide solution was added to the reaction liquid which then was extracted with chloroform. The chloroform layer was dried on anhydrous magnesium sulfate and the solvent was distilled off. The residue was washed with chloroform-methanol, to provide 12.2 g of the title compound as a pale yellow solid.
