A Naphthylamine

Basic Component. The filtrate from (a), or the HCl extract from b), now contains the basic component in the form of its hydrochloride. Add 30% aqueous NaOH solution until alkaline to litmus. Cool, and scratch the sides of the vessel with a glass rod a white precipitate indicates a solid amine, e.g, p-toluidine or a naphthylamine. Dilute, filter off, wash well with water (recrystallise if necessary), dry and identify. 

In the naphthalene series, a-naphthylamine is easily obtained by the reduction of the readily accessible a-nitronaphthalene ... 

Place a mixture of 25 g. of a-naphthylamine (Section IV,37) and 125 g. (69 -5 ml.) of concentrated sulphuric acid in a 250 ml. conical or round-bottomed flask, and heat in an oil bath for 4-5 hours or until a test sample, when made alkaline with sodium hydroxide solution and extracted with ether, yields no naphthylamine upon evaporation of the ether. Pour the warm reaction mixture cautiously and with stirring into 300 ml. of cold... 

The initial product, nitrosobenzene, is so easily reduced to p-phenylhydroxyl-amine that it has never been isolated in the free state, but its presence has been established by reaction in solution with hydroxylamine to 3deld a phenyldi-azonium salt, which couples readily with a a-naphthylamine to form the dyestuff phenyl-azo-a-naphthylamine (compare Section IV,77) ... 

Methylaniline Ethylaniline n-Propylaniline n-Butylaniline Benzylaniline 2 -MethyIbenzylamine N-Ethylbenzylamine 2 -Methyl o-toluidine N-Methyl m-toluidine 2 -MethyI p-toluidine N-Ethyl o-toIuidine N-Ethyl m-toIuidine 2S -Ethyl p-toluidine 2 -MethyI a-naphthylamine N-Methyl p-naphthylamine N-Phenyl- a-naphthylamine 2 -Phenyl-P-naphthylamine... 

Determination of melting points (a-naphthylamine, a-naphthol, benzoic acid, succinic acid and p-nitrobenzoic acid). Use the apparatus shown in Fig. II, 10, 2, a. Construction of calibration curve for thermometer. Determination of m.p. of unknown compound. 

Polymer-type antioxidants have been prepared by Eriedel-Crafts reaction of -cresol andp- and/or y -chloromethylstyrene in the presence of boron trifluoride-etherate (198). The oligomeric product resulting from the alkylation of phenyl-a-naphthylamine using C12—15 propylene oligomer in the presence of AlCl or activated white clays is used as an antioxidant additive for lubricating oils (199). 

The metal coordination complexes of both sahcylaldehyde phenyhiydrazone (91) and sahcylaldoxime provide antioxidant (92) protection and uv stabihty to polyolefins (see Antioxidants). In addition, the imines resulting from the reaction of sahcylaldehyde and aromatic amines, eg, p- am in oph en o1 or a-naphthylamine, can be used at very low levels as heat stabiLizers (qv) in polyolefins (93). 

The Bueherer reaetion is the reversible eonversion of a naphthylamine to a naphthol by the action of aqueous sulfite or bisulfite, see references 2 and 3. 

A mechanistic explanation of this selectivity was, however, only given in 1952 (Wittwer and Zollinger). An aminonaphthol coupling component can be considered as a superposition of a naphthol and a naphthylamine. The rates of azo couplings of both these components show the characteristic pH-dependences discussed for naphthols above. For naphthylamines it is the base, and not the ammonium ion, that reacts with the diazonium ion. This pre-equilibrium has a p Ta-value of about 4. Therefore the 1 1 gradient of log A Nh2 against pH is observed only in the range pH <4. 

The first example of a tetrakisimido analogue of the orthophosphate ion, PO, the solvent-separated ion pair [(THF)4Li][(THF)4Li2P(Nnaph)4] (16), was reported by Russell et al. [21]. This complex was isolated in low yield from the reaction of P2I4 with a-naphthylamine in THF/NEt3, followed by the addition of "BuLi. The mechanism of this remarkable redox process is not understood. 

I) The a-naphthylamine may also be isolated directly from the neutralised reactiuii mixture by distillation with superheated steam (Section 1,6). 

Ethy Ibenzy lamine A -Methyl o-toluidine A -Methyl m-toluidine. 2V-Methyl p-toluidine A -Ethyl o-toluidine -Ethyl m-toluidine -Ethyl p-toluidine 2V-Methyl a-naphthylamine 2V-Methyl p-naphthylamine 2V-Phenyl- a-naphthylamine N-Phenyl- p-naphthylamine... 

Acetyl-o-anisidine Acetyl-m-anisidine Acetyl-p-anisldine Acetyl-o-phenetidine Acetyl-m-pbenetidine Acetyl-p-phenetidine (or phenacetin) Acetyl-a-naphthylamine Acetyl- p-naphthylamine... 

Amines. Aniline Benzidine a-Naphthylamine p-Nitroaniline Dimethylaniline. 

Substituted amides suffer hydrolysis with greater difficulty. The choice of an acid or an alkaline medium vill depend upon (a) the solubility of the compound in the medium and (b) the effect of the reagent upon the products of hydrolysis. Substituted amides of comparatively low molecular weight (e.g., acetanilide) may be hydrolysed by boiling either with 10 per cent, sodium hydroxide solution or with 10 per cent, sulphuric acid for 2-3 hours. Other substituted amides are so insoluble in water that little reaction occurs when they are refluxed with dilute acid or dilute alkali for several hours. These include such substances as benzanilide (C(H(CONHC,Hg) and the benzoyl derivative of a naphthylamine (C.HjCONHCioH,) or a toluidine (C gCONHCjH,). For these substances satisfactory results may be obtained with 70 per cent, sulphuric acid this hydrolysis medium is a much better solvent for the substituted amide than is water or more dilute acid it also permits a higher reaction temperature (compare Section IV 192) ... 

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