Reaction #1091772

Reaction equation

nitroaniline

2,4-Difluoro-3-(4-methylpiperazin-1-yl)-6-nitroaniline

→

4,6-difluoro-5-(4-methylpiperazin-1-yl)-1, 2-phenylenediamine

Yield 100.9%

Solvents

ethanol

Conditions

Workup

1. 1
   Otherthat described in preparation 1 (step 4)

Procedure

The nitroaniline derivative (10.0 g, 0.036 mol) (obtained in step 1 above) was hydrogenated using 10% Pd-C (2.0 g) in ethanol (40 mL), following an analogous procedure to that described in preparation 1 (step 4) to yield 4,6-difluoro-5-(4-methylpiperazin-1-yl)-1, 2-phenylenediamine (8.8 g, 98.7%) as a brown viscous oil, which was directly converted to 4,6-difluoro-5-(4-methylpiperazine-1-yl)-2-mercapto-1H-benzimidazole (6.7 g, 65%) by an analogous procedure to that described in preparation 1 (step 5) using carbon disulfide (5.5 g, 0.072 mol), potassium hydroxide (2.5 g, 0.043 mmol), ethanol (70 mL) and water (10 mL). mp 280-281° C.; IR (KBr) 3085, 1475 cm-1 ; 1H NMR (DMSO-d6) δd 2.22 (s, 3H, NCH3), 2.44 (m, 4H, N(CH2)2), 3.02 (m, 4H, N(CH2)2), 6.86 (d, J=12.8 Hz, 1H), 12.90 (brs, 1H, NH); Mass (m/z) 284 (M+.).

Source