Primary aromatic amines derivatizing

Pyrenecarboxaldehyde (101) was used for derivatization of primary aromatic amines to the corresponding Schiff bases, for their determination by HPLC-FLD LOD 1-2 pmol272. 

Fig. 9.8 presents another, more complex type of phosphate prodrugs, namely (phosphoryloxy)methyl carbonates and carbamates (9-26, X = O or NH, resp.) [84], Here, the [(phosphoryloxy)methyl]carbonyl carrier appears quite versatile and of potential interest to prepare prodrugs of alcohols, phenols, and amines. The cascade of reactions leading from prodrug to drug as shown in Fig. 9.8 involves three steps, namely ester hydrolysis, release of formaldehyde, and a final step of carbonate hydrolysis (X = O) or A-decar-boxylation (X = NH). Three model compounds, a secondary alcohol, a primary aliphatic amine, and a primary aromatic amine, were derivatized with the carrier moiety and examined for their rates of breakdown [84], The alcohol, indan-2-ol, yielded a carrier-linked derivative that proved relatively... 

Brede, C., Skjevrak, I. and Herikstad, H. (2003). Determination of primary aromatic amines in water food simulant using solid-phase analytical derivatization followed by gas chromatography coupled with mass spectrometry, J. Chrom. A, 983, 35-42. 

Whenever only primary amines need to be derivatized, fluorescamine often constitutes the reagent of choice. Fluorescamine, although nonfluorescent itself, can react with primary amines forming highly fluorescent pyrrolinones (139-144). Aliphatic primary amines favor derivatization reaction at pH 8-9, whereas primary aromatic amines exhibit optimal reactivity at pH 3-4. Secondary amines are also fully reactive with fluorescamine but their products do not fluoresce. However, secondary amines can be detected with fluorescamine if they are converted to primary amines by oxidation with N-chlorosuccinimide prior to their fluorescamine derivatization (145, 146). Alcohols can also interact with fluorescamine but this reaction is reversible as a result, alcohols just slow down the reaction rate of fluorescamine with primary amines. On the other hand, tertiary amines and guanidines are not reactive at all with fluorescamine. 

Sharma N, Jain A, Verma KK (2011) Headspace solid-phase microextraction and on-fibre derivatization of primary aromatic amines for their determination by pyrolysis to aryl isothiocyanates and gas chromatography-mass spectrometry. Anal Methods 3(4) 970-976. doi 10.1039/C0AY00745E... 

Substituted aromatic amines have been widely used in the chemical industry as intermediates in the production of dyes, pesticides, pharmaceuticals, paints, etc. They may be released into the environment directly as a result of industrial discharge form factories or indirectly as a result of degradation of phenylcarbamates, phenylurea and anilide herbicides, and azodyes. Chromatographic separation and quantification of primary amines is hampered by their polarity that can cause tailing and irreversible adsorption. Aromatic primary amines were derivatized to 7/-allyl-7/ -arylthioureaby... 

The number of reagents that has been used for the identification of primary amines is possibly larger than for any other class of compounds [5], But most of these classical derivatives lie beyond the scope of this chapter. They are covered in other parts of the book acylation in Chapter 3, silylation in Chapter 4 and alkylation in Chapter 5. The different nitrophenyl derivatives are discussed in Chapter 8, and Chapter 9 presents the options for preparing fluorescent derivatives. The only derivatization fitting into the framework of this chapter is the condensation with carbonyls resulting in the formation of Schiff bases or, in the case of aromatic amines, anils. 

Isocyanates and isothiocyanates react with primary and secondary amino compounds, and a variety of derivatization reagents have been reported. Both aliphatic and aromatic amines react with isocyanates to form N,N -disubstituted ureas (Figure 6.2). As an example, aliphatic amines derivatized with phenyl isothiocyanate (PITC) were nicely... 

D. Chambers, Extractive derivatization of primary amines and beta-aminoalcohols with aromatic aldehydes to form Schiff base or oxa-zolidine products for analysis by electron capture gas chromatography, Diss. Abstr. Int. b. 44(7) 2148, (1984). 

Dunning, J. W. and Stewart, J. T., Some new acridinium trifluoromethanesulfonates as spectro-photometric derivatization reagents for aromatic and aliphatic primary amines, Talanta, 38,631 -635,... 

Phenyl isocyanate [40] reacts with aliphatic and aromatic primary and secondary amines to yield N,7vT-disubsti-tuted ureas (Figure 8). The reaction is quantitative and completed in a few minutes. A single, very stable derivative is obtained even with primary amines. Water and alcohols also react with PIC but the amino group appears to be the most reactive (40). The derivatization was carried out in N,N-dimethylformamide (DMF), and an... 

The saturated and unsaturated primary amines from this process are converted through a series of derivatization steps into tertiary amines utilizing reagents such as EO, PO, a,b-unsatu-rated esters, formaldehyde, or acrylolnitrile followed by reduction to the respective alkyldimethyl-and alkylaminopropylamines, all suitable for quatemization with aliphatic and aromatic alkylating agents. Alternatively, the tertiary amines may be neutralized with acids to form the respective tri-alkylammonium salts, which have many of the attributes of the quaternary ammonium salts when maintained at acidic pH. 

When most of the accessible hydroxyl groups in CF6 are derivatized with aromatic groups, however, the general enantioselectivity for primary amines is almost completely lost (Fig. 9c), whereas enhanced separations of a great variety of other chiral compounds can be obtained (Fig. 9f). These observations are readily... 

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