4- Aminobenzoic acid, reaction with

The Niementowski reaction involves condensation of an o-aminobenzoic acid (13) with 2 resulting in a quinolinol (14). 

The reaction of 2-aminobenzoic acid hydrazidcs with ortho esters gives 4-methyl-3//-1,3,4-benzotriazepin-5(4//)-ones 17 or 4-methyl-l//-l, 3,4-benzotriazepin-5(4//)-ones 18, depending on the structure of the hydrazide. Selected examples are given.359 11 360 361... 

To 10.3 g, 0.075 mol aminobenzoic acid neutralized with 5 mol/L sodium hydroxide (or to 3-acetyl aniline in 250 mL of water), was added sodium chloroacetate (26.2 g, 0.225 mol). The solution was refluxed, and the pH was maintained between 10 and 12 by the addition of 5 M aqueous sodium hydroxide solution. After the pH ceased to fall, the solution was refluxed for an additional 1 h and then cooled and acidified with 0.5 mol/L HCl. The crystals were vacuum filtered and dried under high vacuum. The product was recrystallized from an acetone/water mixture. The yield of these aryliminodiacetic acids reaction varied from 3.1 g to 5.3 g. 

Fife et al. have reported intramolecular GB-assisted ester hydrolysis. The pseudo-first-order rate constants (k bj.) are pH-independent from pH 8 to pH 4. The triflnoroethyl, phenyl, and p-nitrophenyl esters of 2-aminobenzoic acid hydrolyze with similar rate constants in the pH-independent reactions, and the rates of these water reactions are twofold slower in D2O than in HjO. The most likely mechanism involves the intramolecular GB assistance by the neighboring amino group. The rate enhanc ents in the pH-independent reaction in comparison with the pH-indepen-dent hydrolysis of the corresponding para-substituted esters are 50- to 100-fold. 

The diazonium salts usually decompose when warmed with water to give a phenol and nitrogen. When treated with CuCl, CuBr, KI, the diazo group is replaced by chlorine, bromine or iodine respectively (Sandmeyer reaction). A diazonium sulphate and hydroxyl-amine give an azoimide. The diazonium salt of anthranilic acid (2-aminobenzoic acid) decomposes to give benzyne. ... 

Amino-3 5-diiodobenzoic acid. In a 2 litre beaker, provided with a mechanical stirrer, dissolve 10 g. of pure p-aminobenzoic acid, m.p. 192° (Section IX,5) in 450 ml. of warm (75°) 12 -5 per cent, hydrochloric acid. Add a solution of 48 g. of iodine monochloride (1) in 40 ml. of 25 per cent, hydrochloric acid and stir the mixture for one minute during this time a yellow precipitate commences to appear. Dilute the reaction mixtiue with 1 litre of water whereupon a copious precipitate is deposited. Raise the temperature of the well-stirred mixture gradually and maintain it at 90° for 15 minutes. Allow to cool to room tempera-tiue, filter, wash thoroughly with water and dry in the air the yield of crude acid is 24 g. Purify the product by dissolving it in dilute sodium hydroxide solution and precipitate with dilute hydrochloric acid the yield of air-dried 4-amino-3 5-diiodobenzoic acid, m.p. >350°, is 23 g. 

Reaction of anthranilic acid (o-aminobenzoic acid) with HN02 and H2SO4 yields a diazonium salt that can be treated with base to yield a neutral diazonium carboxylate. 

Similarly, 17/-1,4-benzodiazepinc-2,5(3//,4//)-dione (3) is cleaved to 2-aminobenzoic acid by hot 70% sulfuric acid the reaction with methanolic methylamine provides /V-methyl-o-aminohippuramide.209... 

Dialkylphosphonoacetic acid esters react with p-aminobenzoic acid to anilides. The potassium salt of the diamyl ester is said to be surface-active [126]. Phosphorus organic carbonic acid amides can also be obtained by the following reaction [127] see Eq. (76). 

In the context of synthesis and exchange reactions of biodegradable drug-binding matrices, starch trisuccinic acid was loaded via imidazolides with amines such as n-butylamine, morpholine, 4-aminobenzoic acid, or 3,4-dihydroxyphenylalanine to prepare the respective amides in high yields [160] an example is presented below. 

Different reactivity of a-oxyalkyl and boryloxyalkyl fragments was revealed in reactions with amines of weak basicity. For example, in the reaction with diphenylamine or o-aminobenzoic acid with a reagent ratio of 1 1, substitution of the oxymethyl group by the aminomethyl one takes place [Eq. (117)]. The P,B-containing heterocycle is retained (89IZV1340). 

The reaction with m- and p-aminobenzoic acids results in the formation of 1,5,3,7-diazadiphosphacyclooctane (155), possessing the structure of a double betaine [Eq. (119)]. These compounds were obtained from bis(hydroxymethyl)phenylphosphine (89IZV1340). 

Aromatic amines that have been used include o-toluidine, p-aminosali-cylic acid, p-aminobenzoic acid, diphenylamine and p-aminophenol. Their ability to react preferentially with a particular carbohydrate or class of carbohydrate is often useful, e.g. p-aminophenol, which shows some specificity for ketoses compared with aldoses and is useful for measuring fructose. These reagents have proved particularly useful for the visualization and identification of carbohydrates after separation of mixtures by paper or thin-layer chromatography, when colour variations and the presence or absence of a reaction aid the interpretation of the chromatogram. 

Aminobenzoic acid 1.4 g 4-aminobenzoic acid + 3.2 ml 90% orthophosphoric acid in 100 ml methanol Dip Reaction with aromatic amine in hot acid... 

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