4 -Nitroimidazole sodium salt

Nitroimidazole sodium salt j3-Chloroethyl morpholine p-Toluene sulfonyl chloride... 

X-ray studies were also performed for bis(l,2,3,5-tetramethyl-4-nitropyrazolium salt [105], l-methyl-4(5)-nitro-5(4)-styrylimidazole [82], I -(/V-morpholino )-4-nitroimidazole [83], 1-sodium salt of 4-[2-[(l-methyl-5-nitro-2-imidazolyl)thio] ethoxy]-benzoic acid [106], l-methyl-4-nitro-5-chloroimidazole [107], omidazole [81], megazole [108], l-methyl-2-nitro-5-vinylimidazole [42], l-[2-(ethylsulfonyl) ethyl]-2-methyl-5-nitroimidazole (tinidazole) and one of the basic tinidazole metabolites - ammonium salt of l-[2-(ethylsulfonyl)ethyl]-4, 5-dihydro-2-methyl-4-nitroimidazole-5on [109], morpholino nitroimidazole derivatives [110, 111], l-(2-bromoethyl)-2-methyl-5-nitroimidazole [112], l-(4-chlorophenacyl)-2-methyl-... 

Similarly, in nitropyrazoles the C-nitro group vas and vs stretching frequencies are found in a range of 1510-1586 and 1320-1408 cm 1 [73, 297, 328, 362-364, 428, 465, 1031-1041], whereas the absorption maxima of nitroimidazole anions are displaced to the low-frequency region -1120-1200 and 1108-950 cm1, respectively [1033], The authors [1033] have established that the nitroimidazole sodium and potassium salts have a structure, with the negative charge mainly located on the nitro group (Scheme 3.45) ... 

Preparation of A -aminoimidazoles can be achieved by reaction with an aqueous solution of sodium hydroxyamine 0-sulfonate. This gives a mixture of the 1-aminoimidazole and its 1,3-diamino quaternary salt, although the method only works for water soluble imidazoles <90AG(E)556>. Treatment of the sodium salt of 2-nitroimidazole with 0-diphenylphosphinylhydroxylamine and dry A -methylpyrrolidine in DMF, followed by addition of benzaldehyde gives the AT-benzylideneamino derivative (57%) which is readily converted into the 1-amino compound <82S592>. (See also <90AHC(49)117, 92AHC(53)86>.)... 

In 1937 Hunter and Hlynka were able to reduce a methanolic solution of 4(5)-nitroimidazole (27 R = H) with sodium amalgam and trap the 4(5)-aminoimidazole (25 R = H) with cyanic acid giving the urea derivative (31) (37BJ488). Other reducing agents gave inferior results. Subsequently, 4(5)-aminoimidazole (25 R = H) was obtained as either its dihydrochloride (30%) or dipicrate salt but the isolation procedures were lengthy and difficult (41 Mil). 

The direct nitration of imidazole with acidic reagents is difficult due to facile nitrogen protonation (pA aH 7). Nitration of imidazoles proceeds in the 4- and 5-positions with the amidine 2-position being quite inert. Imidazole can be directly nitrated to 4,5-dinitroimidazole but no further. 2,4,5-Trinitroimidazole (TNI) can be prepared from the successive nitration of 2-nitroimidazole the latter synthesized from the diazotization of 2-aminoimidazole in the presence of excess sodium nitrite and a copper salt. The nitrative cleavage of polyiodoimidazoles also provides a route to polynitroimidazoles. " ... 

Perhaps more useful are the transformations of diazonium salts. Imidazole-2-diazonium fluoroborate can be converted into the 2-fluoro- and 2-nitroimidazoles, the former by heating or photolysis, the latter with sodium... 

The solution of 5.08 g 2-methyl-4-nitroimidazole in 200 mL 42% tetrafluoroboric acid was cooled to -10°C to this cooled solution was added 5.08 g zinc dust (78 mmol) in portions of 0.1 g with rapid stirring. Each addition was made only after the prior portion had dissolved and the temperature had fallen to at least -5°C. The addition took about 1 h. Small aliquots were removed, diluted with water, and examined by UV. Total loss of the chromophore at 310 nm indicated the completion of reduction. Then a solution 2.04 g sodium nitrite (44 mmol) in 10 mL water was added dropwise. The resulting solution of the diazonium salt was diluted to 380 mL with cold 42% tetrafluoroboric acid and was irradiated under argon in a Pyrex immersion-well photoreactor using a 400-W high-pressure mercury lamp (Riko 400-HA). After 90 min, the diazonium chromophore at 280 nm had disappeared. The solution was cooled to - 10°C with dry ice, neutralized slowly with 25% aqueous sodium hydroxide to pH 5-6, and extracted with EtOAc (5 x 200 mL). The combined extracts were dried over Na2S04 and evaporated. The residual material was purified on 100 mL silica gel with EtOAc as an eluent to give 1.06 g 4-fluoro-2-methylimidazole, in a yield of 27%, m.p. 142-144°C. 

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