4-nitro-l,2-diaminobenzene

NITRO-l,2-DIAMINOBENZENE see ALL500 4 -NITRO-2,4-DICHLORODIPHENYL ETHER see DFT800... 

To a solution of 3-nitro-l,2-diaminobenzene (0.15g, 1 mmol) in hot ethanol (15 ml) and 5 M HCl (4 ml) is added acetylacetonc (0.2 g, 2 mmol). The mixture is heated under reflux ( 10min) (the reaction is monitored by TLC using dichloromethane-ethyl acetate (1 1)), cooled to room temperature and filtered. Further product is obtained by extraction of the filtrate with chloroform (3 X 15 ml). Recrystallization from 75% aqueous ethanol gives the product (0.13 g, 75%). Similarly prepared are a wide range of 2-methylbenzimidazolcs in yields of 74-89%. 

Similarly to 3,3 -diaminobenzidine, other aromatic o-diamines also react with selenium(rV) in HCl medium. The o-phenylenediamine method [30,31] is more sensitive than the DAB method. The following reagents have been proposed for selenium N-methyl-o--phenylenediamine (e = 1.9-10 at 346 nm) [32], 2-aminodiphenylenediamine [33], 4-nitro-1,2-diaminobenzene [34], 4,5-diamino-2,6-dimercaptopyrimidine [35], l,2-diamino-4-chlorobenzene [36], 4,5,6-triaminopyrimidine [37], 3,4-diaminobenzoic acid [38], and 2,3-diaminonaphthalene [39,40]. 

Nitro-l, 4-diaminobenzene, almost blk ndls having a brilliant luster (from w), mp 137°... 

---