O- benzoic add

P-Methylanthraquinone. Use 10-5 g. of p-toluyl o-benzoic add (preceding Section) and 90 g. (46 ml.) of fuming sulphuric acid (20 per cent. S03). Recrystallise the product from alcohol in the presence of a little decolourising carbon. The yield of pure (3-methylanthraquinone, m.p. 176°, is 7 - 5 g. 

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. 

Several authors studied the influence of substituents on activation parameters. Bad-dar et al.315 who studied the polyesterification of y-arylitaconic anhydrides and adds with 1,2-ethanediol found that in the non-catalyzed reaction a p-methoxy substituent decreases both the activation enthalpy and the entropy whereas an increase is observed with a p-chloro substituent. On the other hand, Huang et al., who studied the esterification of 2,2-dimethyl-l,3-propanediol with benzoic, butanedioic, hexanedioic, decanedioic and o-phthalic add found the same values since the activation enthalpy is 64 kJ mol-1 for the first reaction and 61 kJ mol-1 for the others. 

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

Ai/12(dimerization in benzene) in kcal/mole dimer, o-methoxy benzoic add 3 4 0 2 p-mefcho r. f1) n> ei-r acid ... 

Berti and Bottari l s 149 reported that epoxidation of o-carboxy-tmns-Htilbcnc with per benzoic add is a Btoreospccific reaction that can yield either of two lactones (XLII) and (XLITT), depending ou the temperature (Eq. 42). Two lactones (XLlV) and (XLV) can likewise be formed from the corresponding ets-stilbene derivative, the predominance of one over the other being again temperature-dependant (Eq. 43). The five-membered lactones (XLII) and (XLIV) appear (i> be favored at low temperatures. 

Photoreactions involving benzoic add are not common, but it is now reported that the arene moiety is susceptible to substitution in the presence of sodium hypochlorite in aqueous alkali at pH > 12. At ratios of the order of 0.1 for [Q0 ] [PhC02 l, hydroxylation and chlorination of the aromatic ring occur simultaneously with ipso substitution at the carboxylate group (which yields phenol). At high relative concentrations of hypochlorite, the photo-products react further in the dark to yield polychlorinated derivatives. The reaction is discussed in terms of the initial steps being the generation of the active species 0( P), 0( D), O, and Cl from irradiation of C10 . 

Figure 3.6 Experimental isotherm data on ODS, fitted to a Langmuir model, (a) Hydrophilic organics. Mobile phase, 0.20 M Na+ H2PO buffer, pH 6.3, for benzoic adds, water for other compounds Fj, = 70 pl/min, T = 25°C. 1, p-toluidine 2, p-cresol 3, o-toluidine 4, m-cresol 5, 2-amino-4-nitrophenol 6, phenol 7, jH-rdtrobenzoic acid 8, resorcinol 9, hydroquinone 10, benzoic acid, (b) Nucleosides. 1, Adenosine 2, guanosine 3, cytidine 4, uridine. Spherisorb ODS-2, 25 mM Na" " H2PO, pH 7,25°C. Reproduced with permission from ]. Jacobson, J. Frenz and Cs. Horodth, J. Chromatogr, 316 (1984) 53 (Fig. 4a), and J.-X. Huang and Cs. Horvath, J. Chromatogr., 406 (1987) 275 (Fig. 5).

Karthikeyan G, Perumal PT (2003) An ionic liquid mediated efficient oxidation of alcohols using o-iodoxy benzoic add (lBX)-a simple and eco-friendly protocol. Synlett 2249-2251... 

Let us now consider a specific example, that of benzoic acid, as worked out by Flexer, Hammett and Dingwall88. The absorption curves of benzoic add in different media (0-1N HjS04, O-IjV NaOH and in a buffer of Q-IM sodium acetate in 0-35M acetic add) are shown in Figure 7.6. The absorption data at different wavelengths are given in Table 7.5. The pKa of benzoic acid was calculated using the equation... 

Emantioseieetive Birch redmction-atkylation. lire chiral benzoic acid deriv ativc 1. prepared hy ccuidcnsatioit irf o-bydroxybenzcM add with L olinol fob lowed by cycltzation (Mitsunobu reaction), undergoes Birch reduction (K. NHt. HfF, r-butyl aloohot) (oltow cd by alkylation with essentially only 2. 

Values of a l were calculated from thepKa of 4-substituted-[2.2.2]bicy-clooctane-1-carboxylic acids in 50% w/w ethanol-water at 25 by setting in Equation 41 equal to every odd value in the range 1.45 to 1.67. This range was chosen to include all of the choices of L, which had been made previously from the value of 1.464 used by Roberts and Moreland to the value of 1.65 used by Hansch et al. The corresponding o d values were obtained by means of Equation 42, using the Op values of McDaniel and Brown (28). The a and a o values are given in Table 1. The pKa values reported by Thuaire (30) for 4-substituted benzoic acids in ethanol-water mixtures and in ethanol (Table 2) were correlated with the 12 sets of and a n values obtained above by means of the extended Hammett equation. Also studied were pKa values for 4-substituted benzoic adds in ethanol-water mixtures determined by Wepster (31). The substituents studied are set 7 H, Me, Et, OH, OMe, Cl, Br, NO2, CF3, C02Me Set 8 = Set 7, less CF3 Set 6 = Set 8 less Br. 

The 9,10-anthraquinone system is a classic example of an EE mechanism, which includes a synproportionation process. Absorbance versus distance profiles were measured for this reaction and the homogeneous and heterogeneous rate constants were in agreement with those derived from cychc voltammetry [169]. Protonation of the benzophenone anion radical by benzoic add and o-cresol was studied using this technique [170]. A variety of electrode geometries were explored in determining the heterogeneous... 

In a study of 2,2-diphenyIpropyUithium, a product isolated after addition of CO2 and water was o-(l-phenyl-l-methylethyl)benzoic add. Propose a mechanism to account for its formation. 

F.p. — 56-6 to — 56-9°. M.p. - 26°. B.p. 179°/75l mm., 62°/10 mm. Sol. 300 parts 1 0. Misc. with EtOH, Et O. 1 0504. Vdla-tife in steam. Forms bisulphite comp. Reduces NH3.AgNOa but not FehUng s. NaHg —> benzyl alcohol. EasUy ox. to benzoic add. PGg —> benzyUdoie chlcnide, Condmises with primary amines yielding Schiff bases e.g., aniline —> . benzylideneaniline. NH, —> hydrobenzamide. KCN — benzoia, NjaOfi —y benzyl alcohol - - benzoic acid. 

Clark, Am. Chem. J., 1892, 14, 669. ca-Bromo- toluic Acid o-Bromomethyl-benzoic acid, benzyl bromide o-earboxyUc add)... 

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