Benzoic adds

Place I g. of benzamide and 15 ml. of 10% aqueous sodium hydroxide solution in a 100 ml. conical flask fitted with a reflux water-condenser, and boil the mixture gently for 30 minutes, during which period ammonia is freely evolved. Now cool the solution in ice-water, and add concentrated hydrochloric acid until the mixture is strongly acid. Benzoic acid immediately separates. Allow the mixture to stand in the ice-water for a few minutes, and then filter off the benzoic add at the pump, wash with cold water, and drain. Recrystallise from hot water. The benzoic acid is obtained as colourless crystals, m.p. 121°, almost insoluble in cold water yield, o 8 g. (almost theoretical). Confirm the identity of the benzoic acid by the tests given on p. 347. 

From the results of Malek et al.49,561 m 205,206,211) it may be concluded that the various metal derivatives used in esterifications exhibit many common catalytic characteristics. Thus, these authors190 established relationships concerning the free energies of esterification of thirteen ortho-, meta- and para-substituted benzoic adds by 1,2-ethanediol. They obtained Hammett parameters which do not differ greatly from those found for the add-catalyzed esterifications of the same adds with various alcohols. They concluded... 

Hydrogenation, of gallic add with rhodium-alumina catalyst, 43, 62 of resorcinol to dihydroresorcinol, 41,56 Hydrogen peroxide, and formic acid, with indene, 41, 53 in oxidation of benzoic add to peroxy-benzoic add, 43, 93 in oxidation of ieri-butyl alcohol to a,a/r, a -tetramcthyltetra-methylene glycol, 40, 90 in oxidation of teri-butylamine to a,<, a, a -tetramethyltetra-methylenediamine, 40, 92 in oxidation of Crystal Violet, 41, 2, 3—4... 

Lead dioxide as oxidizing agent for conversion of 2-hydroxy-3-methyl-benzoic add to 2-hydroxyiso-phthalic acid, 40, 48 Lithium aluminum hydride, in purification of 1,2-dimethoxyethane, 41, 97... 

Chand P, Kotian PL, Morris PE, Bantia S, Walsh DA, Babu YS (2005b) Synthesis and inhibitory activity of benzoic add and pyridine derivatives on influenza neuraminidase. Bioorg Med Chem 13 2665-2678... 

Detection and result The chromatogram was dried in a stream of warm air for 10 min, inunersed in the reagent solution for 3 s and then subjected to intense UV radiation (high pressure lamp, A = 365 nm) for up to 10 min. Terephthalic hRt 0-5), pimelic (hRf 55), suberic hRf 60), sebadc hRf 65 — 70) and benzoic adds (hRf 70 — 75) together with sorbic, malic, adipic, dtric, tartaric, lactic and fumaric adds only exhibited a reaction on silica gel layers at higher concentrations. 4-Hydroxybenzoic, salicylic and acetylsalicylic adds fluoresced light blue after irradiation. The detection limit per chromatogram zone was 0.5 pg for salicylic add and more than 5 pg for benzoic add. 

The oxidation of toluene to benzaldehyde and benzoic add over V205/Ti02 assisted by microwaves was studied by Liu et al. [82]. The authors conduded that microwave energy can greatly improve the process of selective toluene oxidation. The highest yields of benzoic add were, however, only 38—41% and the highest selectivity was 51% at 80% conversion to benzoic add. 

The mixture is cooled to room temperature, transferred to a 4-1. separatory funnel, and washed with three 300-ml. portions of saturated brine, to remove copper salts, and three 300-ml. portions of 10% aqueous sodium hydroxide, to remove benzoic add (Note 6). The benzene solution is then washed with 150 ml. of brine and is dried over anhydrous sodium sulfate. 

Sandmeyer s synthesis of aromatic nitriles is far more elegant than the removal of water from the ammonium salts of carboxylic acids, which latter reaction is also applicable to benzene derivatives. In particular, the former synthesis permits of the preparation of carboxylic acids via the nitriles, and so provides a complete substitute for Kolbe s synthesis (alkyl halide and potassium cyanide), which is inapplicable to aromatic compounds. The simplest example is the conversion of aniline into benzoic add. The converse transformation is Hofmann s degradation (benzamide aniline, see p. 152). 

J. Cunningham, G. Al-Sayyed, Factors influencing efficiencies of Ti02-sensitised photodegradation. Part 1. Substituted benzoic adds Discrepancies with dark-adsorption parameters,... 

Methoxybenzoic acid o-Anisic acid (8) Benzoic add, 2-methoxy- (9) (579-75-9) Thionyl chloride (8.9) (7719-09-7)... 

A mixed melting point experiment involves mixing a little of the product with some pure compound. In carrying out a mixed melting point experiment for the benzoic acid obtained by the hydrolysis of ethyl benzoate, some crystals of the laboratory-synthesised benzoic add are mixed with pure benzoic acid. If the two compounds are Identical, then a melting point of the correct temperature range will be obtained. If the melting point is lower than expected, then it is likely that the product is either impure or Is not benzoic acid. 

World Health Organization Concise International Chemical Assessment Document (CICAD) Benzoic Add and Sodium Benzoate, No. 26, 38pp. International Programme on Chemical Safety, 2000... 

Amino-3-fluorobenzoic acid is an important intermediate in the synthesis of derivatives of indole, such as the potent and selective thromboxane/prostaglandin endoperoxide receptor antagonist L-670,596 or the anti-inflammatory agent Etodolac. Compounds of this type have therapeutic applications. 2-Amino-3-fluoro-benzoic add is aiso an important precursor for the synthesis of fluoroacridines, which can be converted to interesting tridentate ligands, such as Acriphos. ... 

The broad band decoupled C-NMR spectrum of benzoic add is shown in Figure 8. The spectrum was recorded at room temperature in chloroform-d on a Hitachi R-1900 FT NMR spectrometer operating at 22.6 MHz. Chemical shifts were measured relative to tetramethylsilane, and assignments for the observed peaks are found in Table 5. 

Figure 1 Doubleproton transfer in benzoic add dimers. When the 0-0 bond length becomes shorter, tunneling is enhanced.

---