Anilinium hydrochloride

SAQ 7.20 Following from SAQ 7.19, the same electrode was then immersed in a solution of anilinium hydrochloride of pH = 2.3. What will be the new emf ... 

For indole synthesis, the best additive both for yield and regioselectivity was found to be the anilinium hydrochloride (PhNH2- HCl). The formation of the indole product can be explained by the isomerization of the hydroamination product, in which it has been clearly shown that the ruthenium catalyst is not involved. 

Aniline has been one of the most important compounds in the first years of the chemical industry and its importance is still high. Nowadays, the major use of aniline is in the manufacture of polyurethanes. Aniline itself is produced mainly from nitrobenzene by reducing it with iron and dilute hydrochloric acid. Aniline is released from the formed anilinium hydrochloride by sodium carbonate treatment. 

Why should the acetic anhydride not be allowed to stay in contact with the aqueous solution of anilinium hydrochloride (14) for an extended period of time before the solution of sodium acetate is added ... 

Why is aqueous sodium acetate preferred to aqueous sodium hydroxide for the conversion of anilinium hydrochloride (14) to aniline ... 

C6H5-NH3 C1-Anilinium hydrochloride salt (water soluble)... 

The second stage of the reaction sequence requires that a solution of sodium acetate be added to the reaction mixture after initial addition of acetic anhydride to the purified anilinium hydrochloride salt solution ... 

The effect of pH is rarely of use for pK measurement it is more often of use in identifying the site of protonation/deprotonation when several basic or acidic sites are present. Knowing the incremental substitutent effects Z of amino and ammonium groups on benzene ring shifts in aniline and in the anilinium ion (40), one can decide which of the nitrogen atoms is protonated in procaine hydrochloride (problem 24). 

Pyridylmethylphosphinates can be accessed, albeit in low isolated yield, by palladium-catalyzed cross-coupling of 2- and 3-pyridylmethyl chlorides with anilinium hypophosphites <2005T6315>. For example, 3-chloromethylpyr-idine hydrochloride reacts with anilinium hypophosphite in the presence of Pd(OAc>2, dppf, 1,4-diazabicy-clo[2.2.2]octane (DABCO), and (BuOTSi as esterification agent to give butyl (pyridine-3-ylmethyl)phosphinate 53 in 46% yield (Equation 37). This transformation proceeds in 24% yield when performed on 2-chloromethylpyridine. 

This mesomeric (or M) effect is seen when aniline is placed in a solution of pH 8-14, i.e. when the basic aniline is unionised. When aniline is placed in a solution of pH < 7, the A,max returns to virtually the value obtained for benzene (203 nm). What is happening is that aniline in acidic solution reacts to form the anilinium salt. The lone pair of electrons on the nitrogen is now involved in bond formation to an H+ ion and can no longer function as an auxochrome. The structure of aniline hydrochloride is shown in Figure 7.8. 

C2H5)3N + HCl (C2H3)3NH Cl-Sometimes amine salts are named using the suffix -ium . For instance, aniUne (CgH5NH2) forms anilinium chloride CgH5NH3 Cl . Often insoluble alkaloids are used in medicine in the form of then-amine salt (sometimes referred to as the hydrochloride ). 

Synonyms Aniline chloride Aniline salt Anilinium chloride Benzenamine, hydrochloride Cl 76001 Hydrochloride benzenamide Phenylamine hydrochloride Phenylammonium chloride... 

Aniline violet. See Basic violet 3 Aniline yellow. See p-Phenylazoaniline Anilinium chloride. See Aniline hydrochloride Anilinoacetic acid. See N-Phenyl glycine p-Anilinoaniline. See N-Phenyl-p-phenylenediamine... 

Do you expect a solution of anilinium chloride (aniline hydrochloride), C6H5NH3CI, to be acidic or basic (Anilinium chloride is the salt of aniline and hydrochloric acid.) Write the equation for the reaction involved. What is the equilibrium expression How would you obtain the value for the equilibrium constant from Table 17.2 ... 

The mechanism of activation of deoxyribonucleoside phosphoramidites by IH-tetrazole has recently attracted considerable attention. It has been argued that the protonation of the phosphoramidite function by l f-tet azole was rapid and followed by the reversible and slower formation of a phosphorotetrazolide intermediate (39). It is to be noted that relative to 5-(p-nitrophenyl)- IH-tetrazole (55), 1 -hydroxy-benzotriazole (24), / /-methylanilinium trifluoroacetate (40), iV-methyl-anilinium trichloroacetate (41), 5-trifluoromethyl-l//-tetrazole (23), A-methylimidazole hydrochloride (23), and )V-methylimidazole-trifluoromethane sulfonate (42), which have also been tested as activators, l/f-tetrazole still remained the most commonly used reagent for the activation of deoxyribonucleoside phosphoramidites. 

Quaternary salts have systematic names such as triethylmethylammonium chloride, - - - -trimethyl-anilinium bromide, 1-methylquinolinium picrate. Quaternary salts are, however, often handled by an older method, as metho-salts, 6.., triethylamine methochloride, quinoline methopicrate this older method should not normally be used, though it is useful for compounds of uncertain composition (cf. hydrochloride, eic.). Salts derived by addition of Me2S04 are named after the pattern of 1-methylpyrid-inium methyl sulphate or naphthalene-l,6-diamine monomethosulphate, the trivial name methosulphate... 

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