Amines dinitrophenyl derivatives

The dinitrophenyl derivatives are reduced by titanium(III) chloride in acidic medium in the first step of the reaction to the corresponding aromatic amines these are then diazotized and coupled with N-(l-naphthyl)-ethylenediamine to yield an azo dye (cf. Fig. 21). 

Dinitrophenyl derivatives. The halogen atom in 2 4-di-nitrochlorobenzene is reactive and coloured crystalline compounds (usually yellow or red) are formed with primary and with secondary amines ... 

Determination of the iV-terminal acid in the peptide can be made by treatment of the peptide with 2,4-dinitrofluorobenzene, a substance very reactive in nucleophilic displacements with amines but not amides (see Section 14-6B). The product is an N-2,4-dinitrophenyl derivative of the peptide which, after hydrolysis of the amide linkages, produces an iV-2,4-dinitrophenyl-amino acid ... 

Cohen and Wheals [334] determined ten hydrolysable carbamate and substituted urea herbicides in soil in amounts down to 0.001-0.05 ppm. In this method, a solution of the herbicide-containing extract of the soil is spotted onto a silica gel G plate and developed with hexane acetone (5 1). The plate is sprayed with 1-fluoro-l,4-dinitrobenzene in acetone and heated to 190 °C to produce the 2,4-dinitrophenyl derivative of the herbicide amine moiety acetone extracts of the areas of interest are subjected to gas chromatography. 

Fig. 5.8. Gas chromatogram of a mixture of 2,4-dinitrophenyl derivatives of amines. Peaks 1 = ammonia 2 = diethylamine 3 = isopropylamine 4 = rm.-butylamine 5 = sec.-butylamine 6 = iso-amylamine 7 = n-amylamine 8 = TMS-ethanolamine 9 = aniline 10 = cyclohexylamine 11 = benzyl-amine 12 = (3-phenylethylamine. Conditions glass column, 3 m X 3 mm I.D., 10% SE-30 on Chromo-sorb W (60-80 mesh, AW, silanized) nitrogen flow-rate, 35 ml/min temperature programme, 2°C/min (190-220°C), 3°C/min (220-250°C). (Reproduced from J. Chromatogr., 88 (1974) 373, by courtesy of S. Baba.)...

To obtain non-polar derivatives silylation is also used, but it should be noted that amino groups are relatively difficult to silylate [131, 305-314]. Nanogram amounts of amines are determined via their dinitrophenyl derivatives formed with l-fluoro-2,4-dinitrobenzene [191, 315—318] or 2,4-nitrobenzenesulphonic acid [319]. A sensitive method for determining amines using an BCD was proposed by Moffat and Homing [320], who used the condensation of pentafluorobenzaldehyde with amines to obtain derivatives. 

The 2,4-dinitrophenyl derivatives of glucosamine and galactosamine are resolved on silica gel G layers buffered with 0.1 M potassium tetraborate (pH 10.8) with the solvent n-propanol-ethyl acetate-water (70+ 10 + 20) [40]. One ascent (10—12 cm) on a 250 [x thick layer requires 60—90min kR/-values DNP-glucosamine, 46 DNP-galactos-amine, 33. The DNP-derivatives are detected by their yellow color. 

Amines react readily with 2,4-dinitrofluorobenzene in the presence of sodium bicarbonate to form the corresponding dinitrophenyl derivative (equation 35) . These compounds like most dinitro-... 

Appllca.tlons. Various A/-derivatives of amino acids (qv) are resolvable on BSA columns. These /V-amino acid derivatives include ben2enesulfonyl-, phthalimido-, S-dimethylarnino-l-naphthalenesulfonyl- (DANSYL-), 2,4-dinitrophenyl- (DNP-), and 2,3,6-trinitrophenyl- (TNP-) derivatives (30). Amines such as Prilocain, ( )-2-(prop5lamino)-(9-propiono-toluidide, a local anesthetic (Astra Pharm. Co.), are also resolved on BSA. The aromatic amino acids DL-tryptophan, 5-hydroxy-DL-tryptophan, DL-kynurenine [343-65-7] C qH 2N 2 3 3-hydroxy-DT.-kynurenine [484-78-6] and dmgs... 

Another example of the analogy between pyrazole and chlorine is provided by the alkaline cleavage of l-(2,4-dinitrophenyl)pyrazoles. As occurs with l-chloro-2,4-dinitrobenzene, the phenyl substituent bond is broken with concomitant formation of 2,4-dinitrophenol and chlorine or pyrazole anions, respectively (66AHC(6)347). Heterocyclization of iV-arylpyrazoles involving a nitrene has already been discussed (Section 4.04.2.1.8(i)). Another example, related to the Pschorr reaction, is the photochemical cyclization of (515) to (516) (80CJC1880). An unusual transfer of chlorine to the side-chain of a pyrazole derivative was observed when the amine (517 X = H, Y = NH2) was diazotized in hydrochloric acid and subsequently treated with copper powder (72TL3637). The product (517 X = Cl, Y = H) was isolated. 

The Zincke reaction is an overall amine exchange process that converts N- 2,A-dinitrophenyl)pyridinium salts (e.g, 1), known as Zincke salts, to iV-aryl or iV-alkyl pyridiniums 2 upon treatment with the appropriate aniline or alkyl amine. The Zincke salts are produced by reaction of pyridine or its derivatives with 2,4-dinitrochlorobenzene. This venerable reaction, first reported in 1904 and independently explored by Konig, proceeds via nucleophilic addition, ring opening, amine exchange, and electrocyclic reclosure, a sequence that also requires a series of proton transfers. By... 

An easily accessible DA CSP derived from L-A-(2-naphthyl)valine (80) was used to separate appropriately derivatized amines, amino alcohols and thiols, derivatization consisting of N-, O- and 5-acylation with 3,5-dinitrobenzoyl chloride or 3,5-dinitrophenyl... 

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