To a mixture of N-methyl-4-(4-nitrophenoxy)-2-nitroaniline (Intermediate 8B -2.10 g, 2.27 mmol) in MeOH (100 mL) was added 5% Pd—C (catalytic amount) and stirred at room temperature under H2 atmosphere. After 7 hrs, the catalyst was removed by filtration then the solvent was evaporated off. The residual mixture was dissolved into MeOH (50 mL) and added 1,3-bis(methoxycarbonyl)-2-methyl-2-thiopseudourea (3.0 g, 14.5 mmol). The mixture was refluxed overnight. The solvent was removed by evaporation and sequence purification on SiO2 column chromatography gave title compound (87.3 mg, 4%): MS m/e 313 (M+1).
