Dimethylaminobenzoic acid

Dimethylamine, reaction with phosphorus trichloride, 46, 42 f-Dimethylami nobenzaldehyde, conversion to 0,/9-dichloro- -dimethyl-aminostyrene, 46, 34 tn-Dimethylaminobenzoic acid, 47, 71 /5-Dimethylaminobenzoic acid, 47, 71 6.(Dimethylamino)fulvene, 47, 52 -Dimethylaminophenylacetic acid, 47, 71... 

Molecular rotors with a dual emission band, such as DMABN or A/,A/-dimethyl-[4-(2-pyrimidin-4-yl-vinyl)-phenyl]-amine (DMA-2,4 38, Fig. 13) [64], allow to use the ratio between LE and TICT emission to eliminate instrument- and experiment-dependent factors analogous to (10). One example is the measurement of pH with the TICT probe p-A,A-dimethylaminobenzoic acid 39 [69]. The use of such an intensity ratio requires calibration with solvent gradients, and influences of solvent polarity may cause solvatochromic shifts and adversely influence the calibration. Probes with dual emission bands often have points in their emission spectra that are independent from the solvent properties, analogous to isosbestic points in absorption spectra. Emission at these wavelengths can be used as an internal calibration reference. 

Fig. 13 Self-calibrating dyes DMA-2,4 and p-A,A-dimethylaminobenzoic acid. Compound 40 is an engineered ratiometric dye composed of a viscosity-sensitive molecular rotor and a nonviscosity-sensitive reference dye [70]...

Jiang Y (1994) pH Dependence of the twisted intramolecular charge transfer(TICT) of p-N, N-dimethylaminobenzoic acid in aqueous solution. J Photochem Photobiol A Chem 78 (3) 205-208... 

For oxalate detection, authors proposed a similar detection approach for recognition of oxalate via an immobilized oxalate oxidase/peroxidase couple and dye precursors MBTH (3-methyl-2-benzothiazolinone hydrazone) and DMAB (3-dimethylaminobenzoic acid). The peroxide generated by oxidation of oxalate to CO2 reacted with the dye precursors in a peroxidase-catalyzed reaction to yield an indamine dye with absorption maximum at 590 nm. The concentration of oxalate was correlated with increased absoiption from dye. 

More recently, the esterification of oxadiazolinone 89 by 4-dimethylaminobenzoic acid in dry CH2CI2 in the presence of dicyclohexylcarbodiimide (DCC) was described to afford compound 90 (70%). The structure of the product was based on NMR, IR, and MS spectra <2000JLR545>. No other similar reaction was found. 

Ion exchanger colorimetry has been used as a sensitive and rapid method for vanadium analysis by immobilization of 2[2-(3-5-dibromopyri-dyl)azo]-5-dimethylaminobenzoic acid onto an ion exchanger resin AG 1X2 [75]. Solid phase fluorimetry can be useful for the analysis of very dilute solutions in water analysis or trace metal determination thus a chelating 8-(benzene-sulfonamido)quinoline, immobilized on Amberlite XAD2 support, has been used for the spectrofluorimetric determination of Zn(II) and Cd(II) [76]. 

There are two main synthetic routes to Crystal Violet Lactone (CVL) and its analogues (Figure 1.23). The first involves the condensation of 4,4 -bismethyhydrol (1.73), also called Michler s Hydrol, with 3-dimethylaminobenzoic acid in dilute acid to give the leuco CVL, which is then oxidised to CVL. A wide variety of oxidants can be used but the preferred method uses hydrogen peroxide in basic solution. The oldest, and most versatile route starts by reacting 4-dimethylaminobenzaldehyde... 

Dimethylaminobenzoic acid and derivs 5 D1308 2,5-dinitro-2-dimethylaminobenzoic acid 5 D1308... 

Fig. 2.4. Absorption A, fluorescence F, and degree of polarization of fluorescence P of DMABN and DMABEE (p-dimethylaminobenzoic acid ethylester) in n-hexane at room temperature, c = 5 x 10 M, and ethyl alcohol at 140 K, c = 1 x 10 4Af, respectively. Arrows indicate excitation wavenumber for measurements of P.6 Subscripts A and B refer to final and initial emission, respectively.

By implication, the H-bonding within the dimer seems to be of some importance. The accuracy of this predic-tion was tested by mixing 3,5-dinitrobenzoic acid with p-dimethylaminobenzoic acid to see if a 1 1 crystalline material formed. In this case, H-bonding between the nitro and amino groups is precluded by the methylation of the amino groups. Apparently, a stoichiometric mixed solid does form (as evidenced by an unmistakable change in color to red), although the structure has not yet been determined. 

Condensation of Michler s hydrol (12) with 3-dimethylaminobenzoic acid (13) gives leuco crystal violet carboxylic acid (14), which is then oxidized to crystal violet lactone. 

In the aromatic series such a reaction is more often observed. For example, p- dimethylaminobenzoic acid can be nitrated to 2,4-dinitrodimethylaniline (Re-verdin [201]) ... 

Thermolysis of peroxide [29c] in benzene solution generates a chemiluminescent emission whose spectrum is identical to the fluorescence spectrum of photoexcited p-dimethylaminobenzoic acid under similar conditions. Thus the direct chemiluminescence is attributed to the formation of the singlet excited acid. The yield of directly generated excited acid is reported to be 0.24% (Dixon and Schuster, 1981). Since none of the other peroxybenzoates generate detectable direct chemiluminescence it was not possible to compare this yield to the other peroxides. However, by extrapolation it was concluded that the dimethylamino-substituted peroxide generates excited singlet products at least one thousand times more efficiently than does the peroxyacetate or any of the other peroxybenzoates examined. 

For the dimethylamino-substituted peroxyester [29c] a third type of behavior is observed. The corrected chemiluminescence intensity obtained is independent of the structure of the activator. This is just what is expected for simple indirect chemiluminescence where the activator is excited by energy transfer from some first-formed singlet state. As indicated above, the initial excited state in this system is p-dimethylaminobenzoic acid. Evidently, the electron donating p-dimethylamino-substituent renders the peroxybenzoate [29c] sufficiently difficult to reduce that the value of k2 is so small that the bimolecular path is never able to compete successfully with unimolecular decomposition. 

Other examples of ancillary ligands used to enhance analyte selectivity include amide-modified D03A (1,4,7,10-tetraazacyclododecane-l,4,7-trisacetate) complexed to Tb , which selectively binds the bidentate analytes p-dimethylaminobenzoic acid (DMABA) and SA (160-162). The binary complex of with EDTA can effectively detect SA, 4-aminosalicylic acid and 5-fluorosalicylic acid (163). [Tb(EDTA)] also has been used to detect catalysis of hydroxybenzoic acid (HBA) by hemin via formation of a ternary complex with the HBA oxidation product (164). Diaza-crown ethers have been utilized with and Eu to detect phthalate, benzoate,... 

Sigma values for smaller substituents are more likely to be additive. However, in the case of 3-methyl, 4-dimethylaminobenzoic acid, the discrepancy is high. For example,... 

C9H11N02 3-dimethylaminobenzoic acid 99-64-9 527.65 46.547 2 17089 C9H120 phenyl propyl ether 622-85-5 463.05 40141 O... 

Dinitro-4-dimethylaminobenzoic Acid, orn-yel ndls, mp 246° sol in hot ale si sol in glac acet ac insol in cold w benz... 

Fig. 2. Fluorescence spectra of dimethylaminobenzoic acid esters in swollen and dried (Nl) polydimethyl-siloxane networks, as a reference the spectrum of the probe in THF is plotted, the intensity is plotted in a. u.

Obviously, amino and nitro groups form strong N—H O hydrogen bonds to yield a supramolecular assembly, while the C—H O bond is a weaker interaction potentially able to form supramolecular species. This is the case of /V, /V -dimethy I am i noan i line and nitro derivatives, as reported in 90. 4-/V,/V-Dimethylaminobenzoic acid and 4-nitrobenzoic acid are assessed in the pattern depicted in 91. 

Bromo-and chloro- derivatives of 2-pyridylazo reagents are more sensitive. The 5-Br-PADAP method has already been described. Other halogen-derivatives used in determining cobalt are 2-(5-chloro-2-pyridylazo)-5-diethylaminophenol (5-Cl-PADAP, formula 18.4) (e = 1.06-10 ) [43], 2-(5-bromo-2-pyridylazo)-l,5-diaminobenzene (5-Br-PADAB) (formula 18.5) (e = 1.16-10 ) [44,45], 2-(3,5-dichloro-2-pyridylazo-5-dimethylaminophenol) (e = 8.4-10" ) [46], and 2-(3,5-dibromo-2-pyrldylazo)-5-dimethylaminobenzoic acid (e = 1.55-10 at 673 nm) [47]. 

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