Dioxo 2- p-

Acid yellow 7 [2,3-dihydro-6-amino-l,3-dioxo-2-(p-tolyl)- H -benz[sulfonic acid monosodium salt, brilliant sulfaflavin. Cl 56205] [2391-30-2]... 

A new spectrophotometric procedure was elaborated by Khalaf and Rimpler [Kh 80] for the determination of the water content of basic solvents (e.g., pyridine, DMSO, DMFA) based on the reaction of 5-isothiocyanato-l,3-dioxo-2-p-tolyl-2,3-dihydro-lH-benz(de)isochinoline with water. The reaction results in the formation of the 5-amino product of this reagent, causing the appearance of a new absorption band in the vicinity of 430 nm wavelength. The intensity of this new band was shown to be in linear correlation with the water content of the sample between 0.3-0.02 vol%. The reproducibility was found to be + 2.2%. 

Dloxo-2-o-tolyl-3. 4 -dfliydro-[naphtho-l, 2 4.5-triazol] 26 II129. 3. 4 -DiOXO-2.m.tolyl-3. 4 -dihydro-[naphtho-l, 2 r4.5-triazol] 28 II129. 3. 4 -Dioxo-2.p.tolyl-3. 4 -dUiydro-[naphtho-1.2 4.5-triazol] 26 II129. 

Pyridazino[4,3-c]pyridazine, 2,6-dimethyl-3,4-dioxo-2,3,4,6,7,8-hexahydro-4-( p-bromophenylhydrazone) synthesis, 3, 352... 

Cefoperazone Cefoperazone, (6/ ,7/ )-7-[(/ )-2-(4-ethyl-2,3-dioxo-l-piperazincarboxam-ido)-2-(p-hydroxyphenyl)acetamido]-3-[[(l-methyl-l//-tetrazol-5-yl)thio]methyl]-8-oxo-5-thia-l-azabicyclo[4.2.0]oct-2-en-2-carboxylic acid (32.1.2.84), is synthesized by acylating 7-amino-3-(l-methyl-l,2,3,4-tetrazol-5-yl)-thiomethyl-3-cefem-4-carboxylic acid (32.1.2.24) with a mixed anhydride synthesized from ethyl chloroformate and a-(4-ethylpiperazin-2,... 

Only one example of a derivative of this ring system has been reported. This compound, 2,6-dimethyl-3,4-dioxo-2,3,4,6,7,8-hexahydropyridazino[4,3-c]pyridazine 4-(p-bromo-phenylhydrazone) (149), was obtained in the reaction of the lactone (148) with methyl-hydrazine. A proposed mechanism for this unusual reaction is shown (80JHC617). 

After cooling, 400 parts by volume of water are stirred in. The aqueous layer is separated from the xylene, shaken out twice with 40 parts by volume of chloroform and then made acid to Congo red paper with concentrated hydrochloric acid. The oil which separates is taken up in ethyl acetate and the solution obtained is washed with water. After drying over sodium sulfate the solvent is distilled off under reduced pressure and the residue is recrystallized from alcohol. l,2-diphenyl-3,5-dioxo-4-(p-phenylmercapto-ethyl)-pyrazolidine melts at 106° to 108°C. 

Dioxo-2-methyltellurinane12 2.0 g (6.4 mmol) of 3,5-dioxo-2-methyltellurinane 1,1-dichloride are suspended in 40 ml of ice-cold water and the suspension is stirred vigorously. 2.8 g (12.6 mmol) of powdered potassium di sulfite arc added over 10 min. to the stirred suspension. When all of the suspended material has dissolved, the solution is filtered, and the filtrate is concentrated until crystallization occurs. The crystals are filtered and recrystallized from benzene yield 1.2 g (79%) m.p. 100°. 

Dimethyl-l,3-dioxo-2-cyclohexyl 5,5-Dimethyl-l,3-dioxo-2,2-cyclohcxyhdene 4-Methoxyphenyl Tellurium1 1.9 g (4.5 mmol) of 4-methoxyphenyl benzenesulfonylimino tellurium chloride and 1.26 g (9 mmol) of 5,5-dimcthyl-1.3-dioxocyclohexane are suspended in 50 ml of benzene. A solution of 0.46 g (0.6 ml 4.5 mmol) of triethylamine in 10m/of benzene is added dropwise to the stirred suspension and the mixture is allowed to stand for 1 day. The precipitate is filtered off, washed with cold acetonitrile, then with water, and dried in the air yield 1.8 g (79%) m.p. 132° (from acetonitrile). 

Procedure Separately inject equal 20-p.L portions of Impurity Standard Preparation and Sample Preparation into the chromatograph, and record the chromatograms (the approximate retention time of 5-benzyl-3,6-dioxo-2-piperazineacetic acid is 4 min, and the approximate retention time of Aspartame is 11 min). Measure the peak area response of 5-benzyl-3,6-dioxo-2-piperazineacetic acid in each chromatogram. Calculate the percentage of 5-benzyl-3,6-dioxo-2-piperazineacetic acid in the sample by the formula... 

H-1, l -dioxo-4-dicyanomethylidene-2-p-tolyl-6-phenylthiopyran doped poly(styrene). 

DIOXO-2,2,7,9,14,14-HEXAMETHYL- see BIQ660 DIOXATHION see DVQ709 DIOXIME-p-BENZOQUINONE see D R200 DIOXIME-1,4-CYCLOHEXADIENEDIONE see D T1200... 

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