5- dimethyl-4- benzaldehyde

Of the three benzenetricarboxyhc acids, only trimellitic acid as the anhydride is commercially produced in large volume, by Hquid-phase air oxidation of either pseudocumene or dimethyl benzaldehyde. The pseudocumene oxidation is another variant of the cobalt—manganese—bromine catalyst in acetic acid solvent as described in the terephthaUc acid section. The acid is available as a laboratory chemical (99). The lUPAC name of trimellitic anhydride is 5-isobenzofurancarboxyhc acid (l,3-dihydro-l,3-dioxo). 

Pseudocumene, in the presence of acetone and sulphuric acid, gives apparently a mixture of the three isomeric dimethyl-benzaldehydes. Analogously, mesitylene is oxidized to mesity-lenic aldehyde. 

By the same procedure given above, the compounds listed below are converted to aldiehyde derivatives. In each case 50 ml. of the starting organic compound is used with the same amounts of other materials as given above. o-Xylene is converted to 3,4-dimethyl-benzaldehyde, b.p. 225-228°, in 85% yield. p-Xylene is converted to... 

C9H10O 1 -vinyl-3-methoxybenzene 626-20-0 493.31 43.241 2 16694 C9H10O2 4-hydroxy-3,5-dimethyl benzaldehyde 2233-18-3 504.72 44.337 2... 

The reaction has been carried out on large- and small-scale batches (Note 10). This modification, as exemplified by 3,4,5-trimethoxybenzaldehyde, has been applied by the submitters to the preparation of other aldehydes such as 3,4-dimethyl-benzaldehyde (90% yield), 3-benzyloxy-4,5-dimethoxybenz-aldehyde (88% yield, with retention of the benzyl group), and 3-methoxy-4-nitrobenzaldehyde (62% yield, with retention of the nitro group). 

Although little experimental data is available, numerous patents have been issued for the vapor phase catalytic oxidation of various other derivatives containing the benzene nucleus, as well as heterocyclic compounds Thus, fluorene (diphenyl methane) is oxidized to fluorenone with air in the presence of a catalyst containing iron vanadate or other suitable metal salt of the fifth or sixth group of the periodic system at a temperature of 360° to 400°.1,2 Maleic acid and anhydride are formed by the catalytic oxidation of compounds of the furan series, such as furan, furfural alcohol, furfural, methyl furfural, hydroxymethylfurfural, pyromucic acid or mixtures, with air over catalysts of molybdenum, vanadium, or other metals.133 Dimethyl benzaldehyde is formed by oxidizing pseudocumene with air at 550° C. in the presence of a tungsten oxide catalyst. Molybdenum, vanadium, or tantalum oxide catalysts may also be used to form aromatic aldehydes from o-, m-, or p-xylenes, mesitylene, p-cymene, or o-chlorotoluene by air oxidation. Times of contact of 0.3 to 0.4 seconds... 

Benzaldehyde, 2,4-dimethyl-Benzaldehyde, 2,5-dimethyl-Benzaldehyde, 4-(dimethylamino)-Benzaldehyde, 3-ethoxy-4-hydroxy- ethylvanillin Benzaldehyde, ethyl-Benzaldehyde, 4-ethyl-... 

Dimethyl benzaldehyde 3,5-Dimethyl benzaldehyde A/,A/-Dimethylbenzamide 7,12-Dimethylbenz[a]anthracene 4,5-Dimethyl-1,2-benzenediamine... 

Dimethyl benzaldehyde Di methyl benzyl carbinol Dimethyl benzyl carbinyl acetate a,a-Dimethylbenzyl isobutyrate 2,6-Dimethyl-5-heptenal 2,6-Dimethyl octanal 3,7-Dimethyl-1-octanol a,a-Dimethylphenethyl butyrate a,a-Di methyl phenethyl formate... 

Davis and co-workers [25] separated antioxidants on Whatman NOAC 82 acetylated paper using ethanol - benzene - acetylacetone (10 10 1) as mobile phase and potassium-p-diazobenzene sulfonate as detection reagent. Korn and Waggon [26] separated urea based stabilisers on paper using propanol - methanol - water (2 1 1) migration and p-dimethyl-benzaldehyde detection. 

Oxy-3.5-dimethyl-benzaldehyd 8,115. 4.0zy-3.5.dimeUiyl.benzaldehyd 8,115. z-03cy.x.diinethyl benxaidebyd 8 nils. Bemoes un-athyleater 9,110,162, H 88. PhenyleMiggftuie-inetliyleater 9,434,1173, n297. 

AminO 3.6>dimethyl-benzaldehyd 14, 66. y-Anilino-piopyleiioxyd.18 II414. 7.AminO Ohn>inaii 18 II419. 

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