Color reaction amino functions

A solvent-free synthesis of substituted spiroindolinonaphth[2,l-fo][l,4]oxazines through condensation of 2-methylene-l,3,3-trimethylindoline derivatives with 1-nitroso-2-naphthol under microwave irradiation has been described by Fedorova and colleagues (Scheme 6.263) [453], In a typical reaction, an equimolar mixture of the two starting materials was irradiated at 65-110 °C for 15 min to produce the desired spiroindolinonaphth[2,l-fo][l,4]oxazines, which are useful as photochromic compounds. In a related procedure, addition of morpholine to the reaction mixture led to the formation of the corresponding 6 -amino-functionalized spiroindolino-naphth[2,l-fo][l,4]oxazines, which exhibit a strong hypsochromic color shift (not shown) [453]. 

Fig. 31. Analytical color reactions to determine qualitatively the amount of amino functions in polymer phase...

Colorimetric and Fluorimetric Analysis. The functional groups of amino acids exhibit Htde absorption of uv light from 210 to 340 nm where uv absorption spectrometry is most conveniently conducted. Thus color or fluorescence formation reactions are employed for amino acid detection (128). 

Figure 2 NAD biosynthesis subsystem diagram. Major functional roles are shown by 4-6 letter abbreviations (explained in Table 1) over the colored background reflecting the key aspects or modules (pathways) that comprise NAD biosynthesis in various species. Catalyzed reactions are shown by solid straight arrows, and corresponding intermediate metabolites are shown as abbreviations within ovals Asp, L-aspartate lA, Iminoaspartate Qa, quinolinic acid Nm, nicotinamide Na, nicotinic acid NaMN, nicotinic acid mononucleotide NMN, nicotinamide mononucleotide RNm, N-ribosyInicotinamide NaAD, nicotinate adenine dinucleotide NAD, nicotinamide adenine dinucleotide NADP, NAD-phosphate Trp, tryptophan FKyn, N-formylkynurenine Kyn, kynurenine HKyn, 3-hydroxykynurenine HAnt, 3-hydroxyanthranilate and ACMS, a-amino-/3-carboxymuconic semialdehyde. Unspecified reactions (including spontaneous transformation and transport) are shown by dashed arrows.

IR methods can be used to support a proposed intermediate in a reaction or to follow the incorporation of a distinctive functional group (e.g., CHO) onto a resin. IR is especially useful for surfaces such as pins or crowns where NMR techniques are not useful. High-quality IR spectra can be obtained from single beads. The UV spectrophotometric quantitative measurement of Fmoc release from derivatized amino groups is still a very common method for measuring loadings. Qualitative color tests are frequently used to follow reactions to assure completion. The Kaiser ninhy-drin test is the best known of these. An improved method for detection of secondary amines has been reported. ... 

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