2.1.3- Benzoxadiazole 5- nitro

Dipping sointion II Dissolve 0.1 g NBD-chloride (7-chloro-4-nitrobenzofurazan, 7-chloro-4-nitro-2,l,3-benzoxadiazole) in 50 ml ethanol. 

Although derivatives of 2,1,3-benzoxadiazole have been used extensively to make quinoxalines (see Section 1.6.7), the corresponding selena and thia systems have been paid scant attention for that purpose. However, 5-chloro-4-nitro-2,l,3-benzoselenadiazole (456) has been used as a convenient source of 4-chloro-3-nitro-1,2-benzenediamine (457) (HCl + HI, 20°C, 2 h 88%), which was then converted into 6-chloro-5-nitro-2,3(l//,4//)-quinoxalinedione (458) (oxalic acid, 2M HCl, reflux, 2.5 h 23%). ° In addition, irradiation of 2,1,3-benzoselenadiazole (460, X = Se) or 2,1,3-benzothiadiazole (460, X = S) with dimethyl acetylenedicarboxy-late afforded, among other products, dimethyl 2,3-quinoxalinedicarboxylate (459)... 

Hu S, Li PCH (2000) Micellar electrokinetic capillary chromatographic separation and fluorescent detection of amino acids derivatized with 4-fluoro-7-nitro-2,l,3-benzoxadiazole. J Chromatogr A 876 183-191... 

Zhang H, Le Potier I, Smadja C et al (2006) Fluorescent detection of peptides and amino acids for capillary electrophoresis via on-line derivatization with 4-fluoro-7-nitro-2,l, 3-benzoxadiazole. Anal Bioanal Chem 386 1387-1394... 

Klinker CC, Bowser MT (2007) 4-Fluoro-7-nitro-2, 1, 3-benzoxadiazole as a fluorogenic labeling reagent for the in vivo analysis of amino acid neurotransmitters using online microdialysis-capillary electrophoresis. Anal Chem 79 8747-8754... 

Benzoxadiazole 64 is calculated to be 1 kcalmol-1 less stable than its ring open form 61 <2004MI1082> and is mirrored by the 4-nitro 65 and 6-carboxyl 66 substituted analogs that exist exclusively as the ring open isomers 62 and 63 <2000IJQ52> (Section 5.03.3.4). 

The chiral purity of amino acids at large enantiomeric excess can be determined automatically by derivatization with 4-fluoro-7-nitro-2,l,3-benzoxadiazole (127b) followed by CE with cyclodextrin chiral selectors and detection of the LIF excitation at 488 nm. Lod 140 ppm of L-phenylalanine in D-phenylalanine324. 

A. Chattopadhyay and E. London, Spectroscopic and ionization properties of V-(7-nitro-2,1,3-benzoxadiazol-4-yl)-labeled lipids in model membranes, Biochim.Biophys.Acta 938, 24-34 (1988). 

Further applications for the determination of the newer antidepressants have employed precolumn derivatization, which included a reaction with dansyl chloride or 4-(N-chloroformylmethyl-N-methyl) amino-7-nitro-2,l,3,-benzoxadiazole (NBD-COCL) followed by separation on ODS Cl8 analytical columns maintained at either 35°C or 70°C using either isocratic or gradient elution with fluorescence end-point detection. The compounds were isolated from human plasma or serum by LLE or SPE techniques using... 

DINITROBENZENEDIAZOOXIDE or DIAZQDI-NITROPHENOL (Called Dinitrodiazophenol or Dinitro-chinon-diazid in Ger), C6H2N4Og, mw 210.11, N 26.67%, OB to C02 -61.0%. Two isomers are described in the literature 4,6-Dinitrobenzeno-2-diozo-l-oxide or 5,7-Di-nitro-1,2,3-benzoxadiazole, (4,6-Dinitro-2-diazo-phenol or 3,5 Dinitro-l,2-benzoquinone-1-diazide), commonly known as Diozodinitrophenol (DADNPh or DDNP) or Dinol q-... 

Greene and Shimizu [77] have reported a displacement assay using a colorimetric dye f/V,/V-dimethyI-/V./V-("7-nitro-2.1,3-benzoxadiazol-4-yl)-l, 2-ethanediamine) with absorption maximum at 460 nm. This assay allowed the determination of seven different aromatic amines. Nevertheless, although the dye seems to be more sensitive in the polymer than in solution, after thorough optimization of the assay conditions, the displacement is only significant for the mmol L 1 amine concentration range. 

Mobile phase 5mM citric acid in methanol DNB=4-fluoro-7-nitro-2,l,3-benzoxadiazole. Source Ref. 20. 

Nitro-7-piperidino[2,1,3]benzoxadiazole, see 4-Nitro-7-piperidinof 1,2,5] benzoxadiazole, 3392b... 

Fig. 5 Smart UV-responsive coating on silica nanoparticles with PNIPAM brushes functionalized with FRET donors, 4-(2-acryloyloxyethylamino)-7-nitro-2,l,3-benzoxadiazole (NBDAE), and photoswitchable acceptors, l -(2-methacryloxyethyl)-3, 3 -dimethyl-6-nitro-spiro(2//-l-benzo-pyran-2,2 -indoline) (SPMA). The UV radiation induces the change from colorless spiropyran derivatives in the outer part of the coating (7) to the fluorescent merocyanine form (2). Thus, FRET with the benzoxadiazole moieties in the inner part of the coating is enabled and the fluorescence color changes from green to red. By variation of the temperature and induction of a collapse of the PNIPAM chains (3), the FRET efficiency can be tuned (4). Reprinted, with permission, from [70], Copyright (2009) American Chemical Society...

Unlike 1,2,3-benzoxadiazoles the existence of which is open to question [208-210], 1,2,3-benzothiadiazoles are well known and their nitration has been described in the literature. On nitration of 1,2,3-benzothiadiazoles with sulfuric-nitric mixture Overberger et al. [211] have obtained 4-nitro-l,2,3-benzothiadiazole. 

The synthesis, structure, and superoxide dismutase mimetic activity in vitro and the protection against reactive oxygen species in vivo of mononuclear copper complexes with 2-(4-methylphenylsulfamoyl)-6-nitrobenzothiazole have been reported [602], Like 1,2,3-benzoxadiazoles, nitroderivatives of 1,2,3-benzothiadiazoles were obtained on diazotization of the corresponding or/Zzo-aminothiophcnolcs [213, 218, 583], The initial or/Zzo-thiophcnols for this reaction were synthesized by nucleophilic substitution of halogen in ort/zo-halogenoanilines. It turned out that 4-nitro- and... 

Nitro derivatives of 2,1,3-benzoxadiazole (benzofurazan) and 2,1,3-benzoxadi-azole-1-oxide (benzofuroxan) were studied by H, 13C, and 15N NMR spectroscopy (Table 3.29) [746-759],... 

The acid-base equilibrium constants of 3-oxy-7-nitrobenzofurazans were determined with the help of UV spectroscopy [1106, 1234], Kinetics of the reaction of methoxydegalogenization and hydrolysis of 4-chloro-7-nitro-2,l,3-benzoxadiazole has been investigated [1106], UV-spectra of some nitrobenzofurazan derivatives are described [1242-1244],... 

UV-visible spectra of porphyrin systems obtained on the base 4-nitro-, 4-chloro-7-nitro-2,l,3-benzoxadiazoles or 4-nitro-2,l,3-benzoselenadiazole have been studied in detail [1241],... 

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