Aminobenzene

Required Aniline hydrochloride, 4 g. aniiinc, 16 ml. diazo aminobenzene, 8 g. acetic acid, 20 ml. 

Chemical Designations - Synortyms Aminobenzene Aniline Oil Blue Oil Phenylamine Chemical Formula C HjNHj. 

Heavily fluonnated aminobenzenes, pyridines, and pyrimidines are diazotized in strong-acid media Solid sodium nitrite added directly to the fluonnated amine dissolved in 80% hydrofluonc acid, anhydrous hydrogen fluoride, or (1 1 wt/wt) 98% sulfuric acid in (86 14 wt/wt) acetic and propionic acids affords the electrophilic fluoroarenediazonium ion Addition of an electron rich aromatic to the resultant diazonium solution gives the fluoroareneazo compound [10 II] (equa tions 9 and 10)... 

Xmino-benzol, n. aminobenzene, aniline, -essig-siure,/. aminoacetic acid, glycine, -kohlen-saure, /. amidocarbonic acid, carbamic acid, sfiure, /. amino acid, -saurerest, m. amino acid residue, -verbindung, /. amino compound. -zucker, m. amino sugar. 

By heating the diacetyl compound with sodium hydroxide solution partial saponification of the acetyl groups takes place. 25.6 grams of diacetyl compound are heated to boiling for some hours with 100 cc of 2 N sodium hydroxide solution. The precipitate produced by acidification of the solution with acetic acid is filtered off and treated with dilute sodium carbonate solution. The 4-aminobenzene-sulfonacetylamide passes into solution while the simultaneously formed 4-acetylaminobenzene-sulfonamide remains undissolved. It is filtered with suction and the filtrate again acidified with acetic acid. The 4-aminobenzene-sulfon-acetamide separates out and is recrystallized from water. It forms colorless lustrous rhombic crystals Of MP 1B1°C. 

These are taken up in 250 cc of 2 N caustic soda solution and heated for 1 hour on a boiling water bath. With hydrochloric acid, the pH is then adjusted to 6 to 7 and the precipitate is filtered with suction and crystallized from 75% ethyl alcohol. The resulting 3-(p-aminobenzene sulfonamido)-2-phenyl-pvrazole crystallizes in white crystals and has a melting point of 177° to 178°C. 

Monosubstitution can occur at any one of the six equivalent carbons of the ring. Most of the monosubstituted benzenes have common names such as toluene (methylbenzene), phenol (hydroxybenzene), and aniline (aminobenzene). 

Aniline (aminobenzene) is an oily liquid that turns brown when exposed to air and light. The compound is an important dye precursor. 

Benzothiadiazole 1,1-dioxide can be conveniently assayed and characterized without isolation by forming its adduct with cyclopentadiene.5 The following procedure illustrates characterization, for assay the same procedure can be applied to an aliquot, with all amounts scaled down in proportion. The dried ether extract of 1,2,3-benzothiadiazole 1,1-dioxide prepared from 1.43 g (0.0080 mole) of sodium 2-aminobenzene-sulfinate is concentrated to about 20 ml at 0°, and 20 ml. of acetonitrile at —20° is added. Twenty milliliters of cold, freshly prepared cyclopentadiene6 is added The mixture is kept overnight at —10° to 0°. Solvent and excess cyclopentadiene are removed by evaporation at 0° under reduced pressure to leave 1.20-1.28 g. (64-68% based on sodium 2-aminobenzenesulfinate) of crude 1-1 adduct, mp. 87° (dec.). For purification it is dissolved in 20 ml. of methylene chloride, 70 ml. of ether is added, and the solution is kept at —70°. Adduct decomposing at 90° crystallizes recovery is about 75%. From pure, crystalline 1, 2, 3-benzothiadiazole 1,1-dioxide the yield of adduct is 92-98%. 

If an aromatic o-diamine such as 1,2-diaminobenzene (2.24) is diazotized in dilute aqueous acid, the 2-aminobenzene-l-diazonium ion formed first (2.25) undergoes a rapid intramolecular N-azo coupling reaction to give 1,2,3-benzotri-azole (2.26). Both amino groups of 2.24 can, however, be diazotized in concentrated acid (Scheme 2-18), forming the bis-diazonium ion 2.27. 1,3- and 1,4-diamines must also be bisdiazotized in concentrated acids in order to avoid inter-molecular N- or C-coupling. 

The monomer of the conducting polymer polyaniline is the compound aniline (aminobenzene). (a) Draw the structural formula of the aniline monomer. What is the hybridization of the N atom in (b) aniline (c) polyaniline (d) Indicate the locations of lone pairs, if any, in polyaniline, (e) Do the N atoms help to carry the current Explain your reasoning. See Box 19.1. 

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