M- Nitrobenzoic acid

The preparation of a number of miscellaneous acids is described. m-Nitrobenzoic acid. Although m-nitrobenzoic acid is the main product of the direct nitration of benzoic acid with potassium nitrate and concentrated sulphuric acid, the complete separation of the small quantity of the attendant para isomer is a laborious process. It is preferable to nitrate methyl benzoate and hydrolyse the resulting methyl w-nitrobenzoate, which is easily obtained in a pure condition ... 

Hydrolysis of methyl m-nitrobenzoate to m-nitrobenzoic acid. Place 90 -5 g. of methyl m-nitrobenzoate and a solution of 40 g. of sodium hydroxide in 160 ml. of water in a 1-htre round-bottomed flask equipped with a reflux condenser. Heat the mixture to boiling during 5-10 minutes or until the ester has disappeared. Dilute the reaction mixture with an equal volume of water. When cold pour the diluted reaction product, with vigorous stirring, into 125 ml. of concentrated hydrochloric acid. Allow to cool to room temperature, filter the crude acid at the pump and wash it with a httle water. Upon drying at 100°, the crude m-nitrobenzoic acid, which has a pale brownish colour, weighs 80 g. and melts at 140°, Recrystalhsation from 1 per cent, hydrochloric acid afibrds the pure acid, m.p. 141°, as a pale cream sohd the loss of material is about 5 per cent. 

Suggest an efficient synthesis of m-nitrobenzoic acid from... 

Nadeau IJ, JC Spain (1995) The bacterial degradation of m-nitrobenzoic acid. Appl Environ Microbiol 61 840-843. 

Iridium-catalyzed transfer hydrogenation of aldehyde 73 in the presence of 1,1-dimethylallene promotes tert-prenylation [64] to form the secondary neopentyl alcohol 74. In this process, isopropanol serves as the hydrogen donor, and the isolated iridium complex prepared from [Ir(cod)Cl]2, allyl acetate, m-nitrobenzoic acid, and (S)-SEGPHOS is used as catalyst. Complete levels of catalyst-directed diastereoselectivity are observed. Exposure of neopentyl alcohol 74 to acetic anhydride followed by ozonolysis provides p-acetoxy aldehyde 75. Reductive coupling of aldehyde 75 with allyl acetate under transfer hydrogenation conditions results in the formation of homoallylic alcohol 76. As the stereochemistry of this addition is irrelevant, an achiral iridium complex derived from [Ir(cod)Cl]2, allyl acetate, m-nitrobenzoic acid, and BIPHEP was employed as catalyst (Scheme 5.9). 

Measurements of the dissociation constants of m-nitrobenzoic acid and p-nitrobenzoic acid began with Ostwald in 1889114. However, the first reasonably precise values were obtained by Dippy and coworkers in the nineteen-thirties, as part of an extensive study of the ionization of carboxylic acids by conductimetric methods115. The pKa values in water at 25 °C of m-nitrobenzoic acid and p-nitrobenzoic acid were found to be 3.493 and 3.425, respectively, compared with 4.203 for benzoic acid itself. On the basis of these values Hammett28,116 proposed 0 values of 0.710 for m-NOy and 0.778 for p-NOy (see Section II.A). These a values have commonly been used thereafter, often rounded to 0.71 and 0.78, respectively. 

Methyl m-nitrobenzoate has been prepared by the esterification of m-nitrobenzoic acid 1 this method is, however, obviously much less satisfactory than nitration of methyl benzoate. Nitration by means of fuming nitric acid has also been applied to methyl benzoate,2 but the use of the ordinary nitration mixture of concentrated sulfuric add and concentrated nitric acid is more satisfactory. 

B is-( 3-nitrophenyl)-furoxan, ndls (from glac acet ac or acet) yel ndls (from xylene), mp 183—85° readily sol in hot xylene, warm glac acet ac St acetone insol in w, ale, eth, petr eth, benz St chlf was prepd by oxidation of 3-nitro-a-benzaldoxime with isoamyl-nitrice in hot benz, or by shaking it. with benzoic acid or m-nitrobenzoic acid Ag salt in eth and by other methods (Refs 2, 3, 4,... 

Methyl benzoate Methyl m-nitrobenzoate m-Nitrobenzoic acid... 

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