P-Hydroxy-a-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... 

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°. 

C44H30CU2N2O1, p-Hydroxy-a-naphthaldehyde- (/3-hydroxy-a-naphthyl-methylimid)copper(II), 35B, 782... 

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. 

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. 

A detailed spectroscopic study of uranyl acetylacetonate [337-339] and other p-diketonates [339], as well as uranyl /u. v-(2-hydroxy-1 -naphthaldchyde) [U02(2H1N)2] [340] and uranyl fe-(2-hydroxybenzaldehyde) [341] was carried out. On the basis of the data obtained, the following structure was assigned to uranyl /u. v-(2-hydroxy-l-naphthaldehyde) [U02(H1N)2] 973 [340] (with permission), whose synthesis was described earlier [342] ... 

There has been a number of developments in the use of salicylaldehydes as precursors of both chromenes and chromans. Alkenes activated by acyl, formyl, nitrile and phenylsulfonyl groups react with 2-hydroxybenzaldehydes and 2-hydroxy-1-naphthaldehyde under Bayliss-Hillman conditions to yield 3-substituted chromenes via the in situ dehydration of the initially formed chroman-4-ol <02JCS(P1)1318>. In like manner, P-nitrostyrenes yield 2- and 2,2-substituted derivatives of 3-nitrochromenes <02H(57)1033>. A simple route to 2-phenyl-2H-chromenes starting from salicylaldehyde and utilising a Pd(0)-catalysed cyclisation of an allylic acetate has been described <02SC3667>. 

Aluminum forms a 1 1 complex with 2-hydroxy-l-naphthaldehyde-/>methoxybenzoylhydraxonal that exhibits fluorescence emission at 475 nm. Under pseudo-first-order conditions, a plot of the initial rate of the reaction (emission units per second) versus the concentration of aluminum (in p,M) yields a straight line described by the equation... 

Deuterium isotope effects on chemical shifts have been reported in P-diketones in which one ring is a pyridine and the other a phenyl ring leading to the establishment of tautomerism [50] and also in Schiff bases of l-hydroxy-2-naphthaldehyde again finding a tentative S-shaped curve [47]. 

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