3- Hydroxy-2-naphthaldehyde

P-Hydroxy-a-naphthaldehyde, Equip a 1 litre three-necked flask with a separatory funnel, a mercury-sealed mechanical stirrer, and a long (double surface) reflux condenser. Place 50 g. of p-naphthol and 150 ml. of rectified spirit in the flask, start the stirrer, and rapidly add a solution of 100 g. of sodium hydroxide in 210 ml. of water. Heat the resulting solution to 70-80° on a water bath, and place 62 g. (42 ml.) of pure chloroform in the separatory funnel. Introduce the chloroform dropwise until reaction commences (indicated by the formation of a deep blue colour), remove the water bath, and continue the addition of the chloroform at such a rate that the mixture refluxes gently (about 1 5 hours). The sodium salt of the phenolic aldehyde separates near the end of the addition. Continue the stirring for a further 1 hour. Distil off the excess of chloroform and alcohol on a water bath use the apparatus shown in Fig. II, 41, 1, but retain the stirrer in the central aperture. Treat the residue, with stirring, dropwise with concentrated hydrochloric acid until... 

The concentration of aluminum in serum can be determined by adding 2-hydroxy-1-naphthaldehyde p-methoxybenzoyl-hydrazone and measuring the initial rate of the resulting complexation reaction under pseudo-first-order conditions.The rate of reaction is monitored by the fluorescence of the metal-ligand complex. Initial rates, with units of emission intensity per second, were measured for a set of standard solutions, yielding the following results... 

Noncatalytic Reactions Chemical kinetic methods are not as common for the quantitative analysis of analytes in noncatalytic reactions. Because they lack the enhancement of reaction rate obtained when using a catalyst, noncatalytic methods generally are not used for the determination of analytes at low concentrations. Noncatalytic methods for analyzing inorganic analytes are usually based on a com-plexation reaction. One example was outlined in Example 13.4, in which the concentration of aluminum in serum was determined by the initial rate of formation of its complex with 2-hydroxy-1-naphthaldehyde p-methoxybenzoyl-hydrazone. ° The greatest number of noncatalytic methods, however, are for the quantitative analysis of organic analytes. For example, the insecticide methyl parathion has been determined by measuring its rate of hydrolysis in alkaline solutions. 

Hydroxy-l-naphthaldehyde [708-06-5] M 172.2, m 82 , b 192 /27mm, pKes, -7.8. Crystd from EtOH (1.5mL/g), ethyl acetate or water. 

The intermediacy of dipolar species such as 186 has been demonstrated by reaction of enamines with 2-hydroxy-1-aldehydes of the aromatic series (129). The enamine (113) reacts in benzene solution at room temperature with 2-hydroxy-1-naphthaldehyde to give the crystalline adduct (188) in 91 % yield. Oxidation with chromium trioxide-pyridine of 188 gave 189 with p elimination of the morpholine moiety. Palladium on charcoal dehydrogenation of 189 gave the known 1,2-benzoxanthone (129). 

P-Naphthol-a-aldehyde (p-hydroxy-a>naphthaldehyde). Proceed as for p-resorcylaldehyde except that 20 g. of p-naphthol replaces the resor-dnol. Recrystallise the crude product (20 g.) from water with the addition of a little decolourising carbon the pure aldehyde has m.p. 80-81°. 

Dwivedi, B. K. et al., Indian J. Chem., 1987, 26A, 618-620 Twelve tris-complexes [Sn(C104)2.3L] between tin(II) perchlorate and Schifif bases derived from salicylaldehyde, anisaldehyde, or 2-hydroxy-l-naphthaldehyde and aromatic amines were investigated for thermal instability. 

It is obtained by condensing 2 moles of 2-hydroxy-l-naphthaldehyde with one mole of hydrazine ... 

With liquid or low-melting ethers no solvent is required. 2-Ethoxy-i-naphthaldehyde has also been prepared by ethylation of the hydroxy compound,11 and from /3-naphthyl ethyl ether by the Gattermann reaction.12... 

The new series of oxovanadium(iv) complexes with Schiff bases derived from 2-aminothiophenol and substituted salicylaldehyde (40) or 2-hydroxy-naphthaldehyde has been synthesized and characterized. The ligands (40a),... 

Fischer s base (1.6 R = H) with saUcylaldehyde (1.7). The same route can be used with an indolinium compound bearing different N-alkyl groups (1.6 R = alkyl) and ring substituents synthesised as shown in Figure 1.2 by alkylation of a 2-methylin-dole to produce (1.8 R = alkyl). Substituted saUcylaldehydes and also 2-hydroxy-naphthaldehydes can also be used to give other analogues. 

The HRP-catalyzed oxidation of 2-hydroxy-l-naphthaldehyde salicylhydrazone (116) with H2O2, at pH 8.5, is finished in about 10 min, and the fluorescent product (A-ex = 296 nm, A-a = 414 nm) persists for 1 h. The results compare well with those obtained by iodide oxidation. LOD is 0.7 nM and LOQ is 2.5 nM. The influence of various factors on flnorescence development was investigated . 

Hydroxy-l -naphthaldehyde sahcylhydrazone hydrogen peroxide determination, 641 hydroperoxide determination, 679... 

The HRP-catalyzed oxidation of 2-hydroxy-1-naphthaldehyde salicylhydrazone (116) reported for H2O2 (Section III.B.2.b) can be applied for the spectrofluorometric determination of polyethyleneglycol hydroperoxides327. The method involving fluorescence of a triple complex of A-(a-pyridyl)-2-thioquinaldamide (120) in the presence of V(V) and H2O2 (Section III.B.2.b) can also be applied to the determination of organic peroxides, represented by z-BuOOH. LOD for Z-BuOOH is 0.03 xM, with RSD 2% (n = 3, 0.5 p,M), and linearity in the 0.1 to 2 p,M range330. 

The coordination process may either stabilize or destabilize aromatic Schiff bases. If nickel (II) salts are added to ammoniacal solutions of salicylaldehyde, the precipitate obtained is the inner complex salt of nickel (II) and salicylaldimine (61). If beryllium chloride is added to the Schiff base derived from 2-hydroxy-l-naphthaldehyde and ethylamine, however, the Schiff base is decomposed and the inner complex of beryllium (II) and 2-hydroxy-1-naphthaldehyde is obtained (59). Here the strength of the coordinate bonds formed with the metal seems to determine which complex will be formed. 

Further supporting evidence is adduced from the observation that the anils of 2 -methoxy- 1-naphthaldehyde and 2-hydroxy-3-naphth-aldehyde show no marked spectral sensitivity to temperature, polarity... 

The reaction of Zr(OCHMe2)4-HOCHMe2 with dibasic ONNO-tetradentate Schiff base ligands derived from diaminoalkanes and salicylaldehyde, 2-hydroxy-l-naphthaldehyde, acetyl-... 

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