• Journal of Photoscience
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• v.11 no.3
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• pp.129-132
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• 2004

Photochemically stable dibenzoylmethane and curcumin were cleaved dramatically when they were irradiated in the presence of N,N-dimethylaniline in methanol with 300 nm UV light. Several products such as benzil, secondary product derived from 1,4-diphenyl-1,4-butanedione, and unidentified compound were observed from the photoreactions of dibenzoylmethane with N,N-dimethylaniline. It was also found that one of the primary fragments produced by irradiation of curcumin in methanol were coupled with N,N-dimethylaniline to give a new enone compound, i.e., 1-(4-dimethylaminophenyl)-4-(4-hydroxy-3-methoxyphenyl)-but-3-en-2-one, as the major product.

• YAKHAK HOEJI
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• v.18 no.2
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• pp.161-164
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• 1974

m-Hydroxyaniline was reported to be converted to m-methoxyaniline with dimethylsulfate. However, while repeating the experiment with the same reaction condition, it was learned that the reaction product was not m-methoxyaniline but m-methoxy dimethylaniline. It was confirmed with nmr and ir spectrum and the comparison of bp and mp of the derivatives. Elemental analyses of the derivatives were also consistant with the fact N-dimethylation along with O-methylation occurred.

• Archives of Pharmacal Research
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• v.4 no.2
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• pp.85-90
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• 1981

A quantitative GC-MS spectrometric assay was used for the determination of residual N, N-dimethylaniline as a contaminant in commercial penicillin derivatives from various sources. The assay utilizes selective ion focusing to monitor in a GC effluent the molecular ions of DMA generated by electron impact ionization. This method includes dissolution of the sample in alkaline solution, extraction of organic base with cyclohexane and injection into GC-MS with a 3% OV-17 column. Levels of 50 ppb of DMA were easily measured with a coeffecient of varation less than 5 % and recoveries from spiked samples exceeded 97 %. The results of the determinations of DMA in various commercial penicillins were relatively free of this contaminant.

• Journal of the Korean Chemical Society
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• v.42 no.1
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• pp.22-27
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• 1998

Fluorescence quenching of coumarin 153 and coumarin 481 with N,N-dimethylaniline in various solvents was investigated. Quenching rate constants are related to diffusion-limited rate constants to some extent. It is noted that smaller discrepancy was observed between the diffusion-limited rate constant and the experimental quenching rate constant when the stick boundary condition rather than the slip boundary condition was applied for estimating the diffusion coefficients. In nonpolar solvent like cyclohexane fluorescence quenching is adequately explained by the diffusion controlled process within the experimental error, but in acetonitrile the quenching rate constant was estimated to be consistently smaller than the diffusion limited rate constant. This may suggest that fluorescence quenching of coumarin dyes be affected not only by the molecular diffusion but also by the intramoleccular process such as charge separation.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.638-639
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• 2000

Quinone reductase was purified to electrophoretic homogeneity from bovine liver by using ammonium sulfate fractionation, ion-exchange chromatography, and gel filtration chromatography. The enzyme utilized either NADH or NADPH as the electron donor. The optimum pH of the enzyme was pH 8.5, and the activity of the enzyme was greatly inhibited by $Cu^{2+}$ and $Hg^{2+}$ ions, dicumarol and cibacron blue 3GA. The enzyme catalyzed the reduction of several quinones and other artificial electron acceptors. Furthermore, the enzyme catalyzed NAD(P)H-dependent reduction of azobenzene or 4-nitroso-N,N-dimethylaniline. The apparent $K_m$ for 1,4-benzoquinone, azobenzene, and 4-nitroso-N,N-dimethylaniline was 1.64mM, 0.524mM and 0.225mM, respectively. The reduction of azobenzene or 4-nitroso-N,N-dimethylaniline by quinone reductase was strongly inhibited by dicumarol or cibacron blue 3GA, potent inhibitors of quinone reductase.

• Journal of the Korean Chemical Society
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• v.19 no.6
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• pp.449-453
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• 1975

Substituent effect of the leaving groups of the reaction of benzyl arenesulfonate with dimethylanilines in acetone at $35^{\circ}C$ was obtained with the following results. 1. Substituent effect of the leaving groups was not variable when changed from pyridine to N,N-dimethylaniline in nucleophile 2.In acetone, the Hammett ${\sigma}$ constant of p-MeO of the leaving group was -0.35. 3. The weaker the nucleophilicity in dimethylaniline, the stronger the movement of electron from N to C, and the cleavage of the C${\ldots}$0 bond in transition state proceeds.

• Bulletin of the Korean Chemical Society
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• v.18 no.10
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• pp.1054-1056
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• 1997

• Journal of the Korean Chemical Society
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• v.36 no.2
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• pp.191-196
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• 1992

Reaction of N,N-dimethylaniline(N,N-DMA) and iodine in $CHCl_3,\;CH_2Cl_2 : CHCl_3$(1:1), $CH_2Cl_2$(1:1), and CH2Cl2 has been studied kinetically by using conductivity method. Pseudo first-order rate constants ($k_{obs}$) and second-order rate constants ($k_{obs}$/[N,N-DMA]) are dependent on the N,N-DMA concentration. Second-order rate constants obtained were decreased with increasing N,N-DMA concentration. We analysed these results on the basis of formation of charge transfer complex as a reaction intermediate. From the construction of reaction scheme and activation parameters for the formation and transformation of charge transfer complex. The equilibrium constants decreased when the dielectric constant of solvent was increased, and the value is 1.9${\sim}$4.2$M^{-1}$. The rate of transformation are markedly affected by the solvent polarity.${\Delta}H^{\neq}$ is 6.3-12.6kJ/mol, and ${\Delta}S^{\neq}$ is large negative value of -234J/mol K.

• Journal of the Korean Chemical Society
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• v.19 no.4
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• pp.240-245
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• 1975

Substituent effects of benzyl substrates for the reaction of substituted benzyl(Z) arenesulfonate(X) with dimethylanilines in (Y) acetone at $35^{circ}$ were studied. The interactions between Z and Y disappeared when changed from electron withdrawing group to releasing group in benzyl substrates. The disappearance of interactions between Z and Y infers change of mechanism from $S_N2 to S_N1$ in substituent Z.

• YAKHAK HOEJI
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• v.22 no.4
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• pp.238-241
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• 1978

A simple and convenient method of detecting N, N-dimethy laniline (D.M.A.) residues in ampicillin trihydrate (A.T.) was established. D.M.A. was extracted by chloroform from the chloroform presaturated N/10-ammonia water solution of A.T. and chromatographed on silica gel G thin layer. Blue spot appeared in 15minutes after spray of 2, 6-dichloroquinonechlorimide solution was compared with the blue spot of reference concomitantly processed. The developing solvent was prepared by mixing equal volume of cyclohexane and chloroform. To quantitate the amount of D.M.A. in A.T., T.L.C. was performed with the Eastmann Chromatogram sheet, then color density was measured by Cosmo Superclick densitometer. The developing solvent at this time was cyclohexane-chlorofonn (3+7) mixture. The peak areas obtained with the amount of D.M.A ranging from 0.05 to 2.0 .mu.g were linear to color density. Better sensitive results would be available with the densitometer equipped with monochromator.