O- toluic acid

Dihydro o toluic acid, 43, 24 Dihydroxycyclopentene, 42, SO Dusobutvlene, oxidation to neopentyl... 

Either Friedel-Crafts disconnection will do, but o-toluic acid (27) is available from the oxidation of o-xylene so that route is preferred as no separation of o, p-isomers is involved. 

The chiral auxiliaries anchored to the substrate, which is subjected to diastereoselective catalysis, is another factor that can control these reactions. These chiral auxiliaries should be easily removed after reduction without damaging the hydrogenated substrate. A representative example in this sense is given by Gallezot and coworkers [268], They used (-)mentoxyacetic acid and various (S)-proline derivates as chiral auxiliaries for the reduction of o-cresol and o-toluic acid on Rh/C. A successful use of proline derivates in asymmetric catalysis has also been reported by Harada and coworkers [269,270], The nature of the solvent only has a slight influence on the d.e. [271],... 

The retention and the peak asymmetry of benzoic acid also indicate the inertness of the bonded phase. If basic compounds remain on the surface or are used as reagents, the peak asymmetry of benzoic acid is poor. The peak height is lower than that of the same quantity of o-toluic acid.3,4 This phenomenon is observed if the basic catalyst that was used in the synthesis process has not been completely washed off the stationary phase or if active amino groups remain. This type of column is not suitable for the separation of acidic compounds. 

Toluene diisocyanate, see 2,4-Toluene diisocyanate o-Toluic acid, see o-Xylene... 

Hydrogenation of phthalic anhydride over copper chromite afforded 82.5% yield of the lactone, phthalide, and 9.8% of o-toluic acid resulting from hydrogenolysis of a carbon-oxygen bond [1015]. Homogeneous hydrogenation of a,a-dimethylsuccinic anhydride over tris(triphenylphos-phine)rhodium chloride gave 65% of a,a-dimethyl- and 7% of )S,)S-dimethyl-butyrolactone [1016]. 

Oeavage of esters to acids and hydrocarbons mentioned above was achieved not only with hydrides but also by catalytic hydrogenation and reduction with metals. For example the acetate of mandelic acid was converted to mandelic acid and acetic acid by hydrogenation at 20° and 1 atm over palladium on barium sulfate in ethanol in the presence of triethylamine in 10 minutes [1035], and a,a-diphenylphthalide was reduced by refluxing for 5 hours with zinc in formic acid to a,a-diphenyl-o-toluic acid in 92% yield [1036]. Such reductions are of immense importance in esters of benzyl-type alcohols where the yields of the acids are almost quantitative. 

The gas-phase selective oxidation of o-xylene to phthalic anhydride is performed industrially over vanadia-titania-based catalysts ("7-5). The process operates in the temperature range 620-670 K with 60-70 g/Nm of xylene in air and 0.15 to 0.6 sec. contact times. It allows near 80 % yield in phthalic anhydride. The main by-products are maleic anhydride, that is recovered with yields near 4 %, and carbon oxides. Minor by-products are o-tolualdehyde, o-toluic acid, phthalide, benzoic acid, toluene, benzene, citraconic anhydride. The kinetics and the mechanism of this reaction have been theobjectof a number of studies ( 2-7). Reaction schemes have been proposed for the selective pathways, but much less is known about by-product formation. 

A more complicated example is the combustion of o-toluic acid ... 

According to this equation, electrons of 7 (out of 8) carbons are shifted (7x4 = 28), as well as all electrons of hydrogen (8x 1 =8), which gives N = 36. As o-toluic acid belongs to the aromatic series, the correction from Khar ash s tables is equal to -3.5x2. This will give ... 

Dinitro-2-methyIbenzoic acid see 3,5-dinitro-o-toluic acid. 

Dinitro-o-toluic acid [28169-46-2] M 226.2, m 206 . Crystd from water. 

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