Phenyl oxalate

Several new oxalates have been developed for use ia analytical appHcations. Bis(2,6-difluorophenyl) oxalate (72) and bis(4-nitro-2-(3,6,9-trioxadecylcarbonyl)phenyl) oxalate (97) have been used ia flow iajection and high performance Hquid chromatography (hplc) as activators for chemiluminescence detectors. These oxalates are generally more stable and show better water solubiUty ia mixed aqueous solvents yet retain the higher efficiencies ( ) of the traditional oxalates employed for chemiluminescence. 

Figure 12.1.3 The reaction of phenyl oxalate ester and hydrogen peroxide to generate a highly energetic C2O4 intermediate.

Figure 2 Structure of te- 2,4-dichloro-6-[(2-dimethylaminoethyl)methylsulfamoyl]-phenyl oxalate dihydrochloride.

Bis[2-(3,6,9-trioxadecyloxycarbonyl)-4- phenyl]oxalate (TDPO), chemiluminescence reagent, 5 847-850 Bis(2,4,4-trimethylpentyl) phosphinic acid, 19 64... 

Warbentin (19) has indicated how the radical thermochemistry involved can assist in assigning a mechanism for the thermal decomposition of phenyl oxalate. Exclusive initial fission of either the one C—C or the two C—O bonds would lead, via PhOCO or OCCO intermediates, to high C02 or high CO yields. In experiments lasting about 75 hours at 500°K. in diphenyl ether, comparable amounts of CO (13%) and C02 (9% ) are formed. The following steps, possibly concerted ... 

The reaction mechanism with phenyl oxalate is shown in Reaction 8. The reaction products, phenol, /Miydroxyethyl formate and cyclic ethylene oxalate, are more diffusible through the PET polycondensation system than is ethylene glycol. 

The LIA is an immunoassay in which the antigen or antibody are labeled with either a chemiluminescent or bioluminescent tags (41, 58). Luminescent molecules are produced by oxidation reactions. Bis-phenyl oxalates in presence of hydrogen peroxides are used for chemiluminescent assays and luciferin in presence of luciferase enzyme is used for bioluminescent assays. The sensitivity of the LIA s are in the pg/ml or lower range. 

Figure 2 Aryloxalates and the PO-CL reaction. TCPO, 6is(2,4,6-trichlorophenyl)oxa-late DNPO, fa s(2,4-dinitrophenyl) oxalate DFPO, 6is(2,6-difluorophenyl)oxalate TDPO, bis[2 (3,6,9-trioxadecyloxycarbonyl)-4-phenyl] oxalate.

The nature of the aryloxalate used in a PO-CL system is an important factor in view of the produced CL intensity. Several aryl oxalates, e.g., A s(2,4,6 Irichloro phenyl)oxalate (TCPO), A/s(2,4 d in it rophenyl)oxalate (DNPO), A/s(2,6 diflu... 

TSK gel ODS-80-TM 5 mM phosphate buffer pH 5-acetonitrile (3 2) [1 mL/min] and 5 mM bis [4-nitro-2-(3,6,9-trioxadecyl oxycarbonyl)phenyl] -oxalate TDPO and 50 mM-acetonitrile [1.3 mL/min] Chemiluminescent reagent. Separates the drug and dansylated valine. Detection limit under the optimum conditions is 20 amol for dipyridamole. 80... 

C9. Capomacchia, A. C., Jennings, R. N., Hemingway, S. M., D Sousa, P., Prapaitrakul, W and Gingle, A., Native peroxyoxalate chemiluminescence from the reaction of bis (2,4-dinitro-phenyl) oxalate and hydrogen peroxide perturbed by non-fluorophores. Anal. Chim. Acta 196, 305-310 (1987). 

Detector Chemiluminescence following post-column reaction. The column effluent mixed with the reagent pumped at 1.4 mL/min and the mixture flowed to the detector. (Reagent was 0.25 mM bis[4-nitro-2-(3,6,9-trioxadecyloxycarbonyl)phenyl] oxalate (TDPO, Wako, Oseika) emd 37.5 mM hydrogen peroxide in MeCN ethyl acetate 50 50.)... 

While the main field of application of chemiluminescence (CL) reactions is catalytic processes (e.g., oxidation of liuninol in the presence of metal ions), some noncatalytic reactions are also of great interest on accormt of the high sensitivity they provide. One of the most prominent of such reactions is that involving the hydrogen peroxide-induced oxidation of aryl oxalate esters in the presence of a suitable fluorescent species (Scheme 2). The most widely used aryl oxalates for this purpose are bis(2,4, 6-trichlorophenyl)oxalate (TCPO) and bis(2,4-dinitro-phenyl)oxalate. These CL reactions have been used... 

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