Penta methyl benzene

CnHie Penta-methyl benzene, etc. C12H18 Hexa-methyl benzene. C13H20 Heptyl benzene. 

There are three possible types of shape and size selectivity effects, as shown in Fig. 4.2S. First, the reactant molecules may be too large to enter the cavities. Comparison of Tables 4.11 and 4.13 shows that all of the molecules access faujasite structures. Only molecules larger than penta-methyl benzene are excluded. Early examples of shape and size selectivity were almost completely limited to small openings and normal versus branched paraffins. For example, n hexane was selectively cracked in the presence of 3-methylpentane over zeolite A catalysts. Other, more subtle, effects may occur. The diffusivity of frart5 butane-2 is 200 times larger than that of cis-butene-2 in zeolite CaA. By adding Pt to CaA, selective hydroge nation of fr[Pg.79]

But in this connection the reaction is in many cases, and indeed in the simplest case, not of equal importance with its application for the ketone syntheses, for three reasons First, the product of the reaction is a hydrocarbon which can again react thus it is often difficult to limit the reaction to the desired point- For example, in the action of methyl chloride on toluene, not only is one hydrogen atom substituted, with the formation of dimethyl benzene, but varying quantities of tri-, tetra-, penta-, and hexa-methyl benzene are also formed. A second disadvantage is this In the different series a mixture of isomers is obtained in the above case, e.g., not only one of the three dimethyl benzenes, but a mixture of the 0-, m-, and p-varieties is formed, which cannot be separated like the homologues by fractional distillation. The reaction is still further complicated in that the aluminium chloride partially splits off the alkyl groups ... 

CgHu, Cyclooctene, iridium complex, 21 102 C10H4, Benzene, l-isopropyl-4-methyl-, ruthenium complex, 21 75 CioHit, 1,3-Cyclopentadiene, 1,2,3,4,5-penta-methyl-, 21 181... 

In addition to the two methyl peaks near 5790 and 5735 cm, the methyl group in aromatic compounds has a band near 5660 cm, which has been found useful for quantitative analysis. Luty and Rohleder assigned this peak to be due to -i- 26. They also suggest that a peak at 4080 cm" is due to 38s, second overtone of a symmetric bending vibration of the CHj group. This peak is well isolated in compounds having multiple methyl groups such as penta and hexa-methyl benzene. 

Ci6H6i,B5oP2 CgHs, Penta(methyl-o-carboranyl)diphosphine benzene solvate, 45B, 737... 

Methyl chloride (—) Aid, (0.3) 80 — Toluene, xylenes, trimethylbemsenes, durene, penta- and hexa-methyl-benzenes 164... 

Garcia-Garcia et al. reported that the gold-catalyzed cycloisomerization of 1,3-dien-5-ynes 128 afforded penta-substituted benzenes 129 (Scheme 27.43) [55]. The reaction is initiated by an intramolecular nucleophilic attack of the terminal alkene, leading to intermediate 130, which is represented as the contribution of several resonance structures, such as ISC and 130". [l,2]-Migration of one of the methyl groups... 

The Pt(CH2 = CH2)(PPh3)2-catalyzed dehydrogenative double silylation of olefins and dienes with o-bis(dimethylsilyl)benzene was also examined by Tanaka and co-workers.61 The major product of the reaction with dienes, such as isoprene and penta-1,2-diene, is a result of 1,2-addition to the less substituted double bond. The reaction pathway for simple alkenes, shown in Eq. (19), appears to be dependent on the alkene substrate and, in some cases, on reaction temperature. Products resulting from 1,2-addition, 1, and 1,1-addition, 2, are detected for various substrates. In addition, hydrosilylation may occur to give the simple hydrosilylated product, 3, or a by-product, 4, derived from 1,4-migration of a methyl group in 3. 

Di-amino derivatives of the secondary amines, mono-methyl aniline, and the tertiary amines, di-methyl aniline, are also known. Of these compounds the para-amino di-methyl aniline is the most important in the dyestuff industry. Tri-amino, tetra-amino, penta-amino and hexa-amino derivatives of benzene and also penta-amino toluene are all known. 

The proofs for the above constitutions are as follows (i) Thymol yields cymene, i-methyl 4-iso-propyl benzene, by loss of the hydroxyl oxygen by means of phosphorus penta-sulphide. (2) Carvacrol may be synthesized from potassium cymene sulphonate by fusion with potassium hydroxide. Therefore both must be mono-hydroxy cymenes. (3) Thymol by means of phosphorus pentoxide splits off the iso-propyl radical yielding meta-cresol and propylene. (4) Carvacrol by the same reaction yields ortho-cresol. Therefore in thymol the hydroxy group is meta to the methyl group while in carvacrol it is ortho. The following relationships are thus established. 

On spraying with 2,6-dichloro-p-benzoquinone-4-chloroimine, ceric sulfate reagent (Seher, 1960, 1961) and especially with antimony penta-chloride (BoUiger, 1962), the tocopherols give different colors which vary also with the adsorbant, as shown in Table IX and Figs. 7 and 8. The reaction with antimony pentachloride (20% in chloroform) depends on the number and position of the methyl gi-oup on the benzene ring and on the nature of the side chain. These color complexes are not stable, however. 

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