Nitration of some di- and tri-nitrohalobenzenes with solid sodium nitrite in the presence of 18 crown 6

1-Halo-4-R-1-6-R-2-2-nitrobenzenes 1a-d (where a: hal = F, R-1 = NO2, R-2 = H; b: hal = Cl, R-1 = NO2, R-2 = H; c: hal = Cl, R-1 = H, R-2 = NO2; d: ha l = Cl, R-1 = CF3, R-2 = NO2;) and 1-chloro-2,4,6-trinitrobezene 1e were ni trated in methylene chloride with solid sodium nitrite in the presence of 1 8C6, and afforded the corresponding nitroderivatives 4-R-1-6-R-2-1,2-dinitr obenzenes 3a-c (where a: R-1 = NO2, R-2 = H; b: R-1 = H, R-2 = NO2; c: R-1 = CF3, R-2 = NO2;) and 1,2,3,5-tetranitrobenzene 3d, respectively. The yiel ds of this nucleophilic process depended on the number of nitro substituent s and on the halogene type. UV-VIS and NMR spectra, TLC behaviour and pH-de pending repartition in biphasic system water/methylene chloride of the synt hecized compounds 3a-d are presented.