Griess

The determination of the amino group is often conveniently accomplished by converting it into the diazoderivative and replacing the nitrogen by chlorine as a rule the diazo-compound is not isolated. The following examplewill serve to illustrate the method  

The following example will illustrate the method of working Aniline (3.1 grams) 

Abnormal chloraurates of isopropylamine, piperidine, i-methylpiperidine, 2-5-dimethylpyrrplidine and quinoline have also been described, they have the 

The methods of acylation described for the determination of hydroxyl are also applicable to the amine 

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Peter Griess synthesized the first azo dye soon after his discovery of the diazotization reaction in 1858. The two reactions which form the basis for azo dye chemistry are diazotization (eq. 1) and coupling (eq. 2) (2). 

Oeaminalion of aromatic amines via diazonium sails, by means of alcohols (Griess), or PO2H3, Sn(OH)2, etc. 

Nitrogen dioxide in ambient air Modified Griess-Saizman method... 

Quinazoline (1,3-diazanaphthalene) was prepared by Gabriel in 1903 although the first derivative tvas synthesized by Griess 34 years earlier. The name was proposed by Widdege. Other names such as phenmiazine, benzo-l,3-diazine, and 5,6-benzopyrimidine have occasionally been used. The numbering suggested by Paal and Busch (1) is still in use. ... 

Aluminium, n. aluminum, aluminium, -blech, n. sheet aluminum, -bor, n. aluminum boride, -draht, m. aluminum wire, -eisen, n. ferro-aluminum. -erz, n. aluminum ore. -feilspane, m.pl. aluminum filings, -fluorwasserstoff-saure, /. fluoaluminic acid, -folie, /. aluminum foil, -formiat, n. aluminum formate, -giesserei, /. aluminum foundry or founding. -griess, m. (coarse) aluminum powder aluminum shot. guss, m. aluminum cast-ing(s), cast aluminum. 

Griess has observed crevice corrosion of titanium in hot concentrated solutions of Cl , SOj I ions, and considers that the formation of acid within the crevice is the major factor in the mechanism. He points out that at room temperature Ti(OH)3 precipitates at pH 3, and Ti(OH)4 at pH 0-7, and that at elevated temperatures and at the high concentrations of Cl ions that prevail within a crevice the activity of hydrogen ions could be even greater than that indicated by the equilibrium pH values at ambient temperatures. Alloys that remain passive in acid solutions of the same pH as that developed within a crevice should be more immune to crevice attack than pure titanium, and this appears to be the case with alloys containing 0-2% Pd, 2% Mo or 2[Pg.169]

N 31.09%, yel prisms, mp explds. Was prepd by Griess (Ref 2) by adding a cold satd aq soln of benzenediazonium nitrate to ammonia. Insol in w, sol in ale and eth with deoompn. In the dry state, it explds violently when heated, or on impact or friction... 

H2N.C6H4.NH2, mw 108.14, N 25.91%. There are three isomers ortho-, meta- and para-. Phenylenediamines were first prepd in the 1860 s by P. Griess and then by A.W. Hofmann. Inasmuch as some confusion existed in regard to the structure of these compds, it is difficult to say which isomers they were... 

The thoroughness and extent of the work of Griess in this field probably account for the fact that Mene (1861) is rarely mentioned in this connection. Independently of Griess, and possibly even before him, Mene obtained 1,3-diphenyltriazene through the action of nitrous fumes on aniline. 

The fact that practically all aromatic amines are readily converted into diazo compounds contributed greatly to Griess s success. The original method (Griess, 1858) by which he diazotized picramic acid (1.1 see Scheme 1-1) consisted of passing nitrous gases, prepared by the reduction of nitric acid with starch or arsenious acid, into an alcoholic solution of the amine. 

In the modern formulation, but ignoring the quinone diazide mesomerism (see Sec. 4.2), his diazotization is shown in Scheme 1-1 yielding 1.2. For the centenary of the discovery of diazo compounds Wizinger (1958) and Cliffe (1959) wrote accounts of its history. More recently Zahn (1989) summarized the life and work of Peter Griess. 

Griess (1864a) had already observed that the diazo compounds obtained from primary aromatic amines in acid solution are converted by alkalis into salts of alkalis. The reaction is reversible. The compounds which Hantzsch (1894) termed sjw-diazotates exhibit apparently the same reactions as the diazonium ions into which they are instantaneously transformed by excess of acid. Clearly the reaction depends on an acid-base equilibrium. 

Aromatic diazonium compounds became industrially very important after Griess (1866a) discovered in 1861/62 the azo coupling reaction, by which the first azo dye was made by C. A. Martius in 1865 (see review by Smith, 1907). This is still the most important industrial reaction of diazo compounds. Hantzsch and Traumann (1888) discovered that a heteroaromatic amine, namely 2-aminothiazole, can also be diazotized. Heteroaromatic diazonium compounds were, however, only used for azo dyes much later, to a small extent in the 1930 s, but intensively since the 1950 s (see Zollinger, 1991, Ch. 7). 

Griess (1860) coined the prefix diazo for the nitrosation product of an aromatic amine, because he assumed that two nitrogen atoms replaced two hydrogen atoms of the parent aromatic compound. On the other hand, azobenzene received its name on the basis of the C H N ratio 6 5 1, indicating the replacement of one hydrogen by one nitrogen atom. 

In the historical introduction to this book (Sec. 1.1) it was mentioned that the discoverer of diazo compounds, Peter Griess, realized quite early (1864 a) that these species could react with alkali hydroxides. Thirty years later Schraube and Schmidt (1894) found that the primary product from the addition of a hydroxide ion to a diazo compound can isomerize to form a secondary product. In this section we will discuss the equilibria of the first acid-base process of aromatic diazonium ions. In the following section additional acid-base reactions will be treated in connection with the isomerism of addition products of hydroxide ions to diazonium ions. 

Griess (1866 b) found that benzenediazonium tribromide (QHsN Br ) in the presence of ammonia is converted into phenyl azide in high yield. The reaction probably proceeds through phenyltriazene, as an intermediate which is subsequently oxidized to the azide by the tribromide ion (Scheme 6-14). 

If an electron is transferred from a reducing agent to an arenediazonium ion, an aryldiazenyl radical (8.47) is formed. As discussed in this section, the latter dissociates rapidly into an aryl radical and N2 (Scheme 8-28). This type of dediazoniation was observed by Griess (1864 c), albeit not in our present formulation. He found that arenediazonium ions formed iodoarenes and N2 in the presence of iodide ions. More important for synthetic organic chemistry were some dediazonia-tions discovered in the late 19th and early 20th centuries, which are catalyzed by metals and metal ions, namely the Sandmeyer, Pschorr, Meerwein, and related syntheses (see Ch. 10). 

It was mentioned earlier (Sec. 8.6) that for iodo-de-diazoniation no catalyst is necessary because the redox potential of the iodide ion (E° = 1.3 V) is sufficient for an electron transfer to the arenediazonium ion. The reaction was actually observed by Griess (1864 c). Four iodo-de-diazoniation procedures are described in Organic Syntheses. For the syntheses of iodobenzene and 4-iodophenol (Lucas and Kennedy, 1943, and Daines and Eberly, 1943, respectively) KI is used in equimolar quantity and in 1.2 molar excess. However, for 2-bromoiodobenzene and for 1,3,4-triiodo-5-nitrobenzene (replacement of a diazonio group in the 4-position by iodine), up to... 

The reaction of azide ions with diazonium ions is preferable to the classical synthesis of aryl azides which was found by Griess (1864d, 1866b) in the reaction of benzenediazonium tribromide with ammonia (see discussion in Sec. 6.4). 

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