Toluene, naming

Some of the scientists of that period (probably friends of Pelletier and Walters), did not approve of Berzehus choice of name for this substance, and two of these, Muspratt and Hoffman, in a research paper dated 1845, take occasion to remark (4) Berzehus has proposed for this compound the name toluol or toluene, names which are not very well chosen, but which we shall retain in the following discussion. ... 

In these examples the base name of the benzene derivative determines the carbon at which numbering begins anisole has its methoxy group at C 1 toluene its methyl group... 

An old name for benzene was phene and its hydroxyl derivative came to be called phe nol This like many other entrenched common names is an acceptable lUPAC name Likewise o m and p cresol are acceptable names for the various ring substituted hydroxyl derivatives of toluene More highly substituted compounds are named as deriv atives of phenol Numbering of the ring begins at the hydroxyl substituted carbon and proceeds m the direction that gives the lower number to the next substituted carbon Sub stituents are cited m alphabetical order... 

Name Acrony m Color CAS Registry Number Mo 1 wt d, mg /m 3 Melting point, °C Sol y, toluene Acute oral LT>5o, mg/kg "... 

As the name implies, these stains are sprayed on and require Httie if any wiping. The solvent itself penetrates into the pore and allows the pigment and a small amount of binder to remain on the surface. These stains usually are composed of an oil-type vehicle and a combination of earth pigments reduced in a combination of aHphatic and aromatic hydrocarbons such as naphtha and toluene. The solvent system itself plays a big role in the appearance of the stain owing to the varying degrees to which solvents penetrate. Restrictions on the use of certain aromatic hydrocarbons have affected the manner in which these stains work. 

Toluene [108-88-3] 7 8 colorless, mobile liquid with a distinctive aromatic odor somewhat milder than that of ben2ene. The name toluene derives... 

Federal name O Glycero 1 CH3O H C3H3O H Petroleu m jelly Toluen e Steari c acid Olei c acid Mineral oil Ethy 1 ethe r Aceton e Butyl acetate... 

Two complementai y reviews of this subject are by Shah et al. AIChE Journal, 28, 353-379 [1982]) and Deckwer (in de Lasa, ed.. Chemical Reactor Design andTechnology, Martinus Nijhoff, 1985, pp. 411-461). Useful comments are made by Doraiswamy and Sharma (Heterogeneous Reactions, Wiley, 1984). Charpentier (in Gianetto and Silveston, eds.. Multiphase Chemical Reactors, Hemisphere, 1986, pp. 104—151) emphasizes parameters of trickle bed and stirred tank reactors. Recommendations based on the literature are made for several design parameters namely, bubble diameter and velocity of rise, gas holdup, interfacial area, mass-transfer coefficients k a and /cl but not /cg, axial liquid-phase dispersion coefficient, and heat-transfer coefficient to the wall. The effect of vessel diameter on these parameters is insignificant when D > 0.15 m (0.49 ft), except for the dispersion coefficient. Application of these correlations is to (1) chlorination of toluene in the presence of FeCl,3 catalyst, (2) absorption of SO9 in aqueous potassium carbonate with arsenite catalyst, and (3) reaction of butene with sulfuric acid to butanol. 

Benzene, which has been used as a solvent successfully and extensively in the past for reactions and purification by chromatography and crystallisation is now considered a very dangerous substance so it hasto be used with extreme care. We emphasise that an alternative solvent system to benzene (e.g. toluene, toluene-petroleum ether, or a petroleum ether to name a few) should be used first. However, if no other solvent system can be found then all operations involving benzene have to be performed in an efficient fumehood and precautions must be taken to avoid inhalation and contact with skin and eyes. Whenever benzene is mentioned in the text an asterisk e.g. C Hg or benzene, is inserted to remind the user that special precaution should be adopted. 

Specific percentage by weight of a toxic chemical In the mixture or trade name product to be a trade secret, your notice to customers must contain a statement that the chemical Is present at a concentration that does not exceed a specified upper bound. For example, if a mixture contains 12 percent toluene and you consider the percentage a trade secret, the notification may state that the mixture contains toluene at no more than 15 percent by weight. The upper bound value chosen must be no larger than necessary to adequately protect the trade secret. 

Like other alkaloids of this group, quinine forms molecular compounds with a variety of organic substances. With benzene and toluene it produces compounds of the formulae B. CgHg and B. C,Hg respectively, with phenol it gives the crystalline product B. CgHjOH, and similar combinations with polyhydric phenols, ethers, aldehydes and ketones are known. One of the most characteristic of these substances is cupreine-quinine, a combination of the two alkaloids, obtainable from cuprea bark, and at first regarded as a new alkaloid, and named homoquinine. ... 

Compounds related to benzene were obtained from similar- plant extracts. Eor example, a pleasant-smelling resin known as toln balsam was obtained from the South American tolu tree. In the 1840s it was discovered that distillation of tolu balsam gave a methyl derivative of benzene, which, not surprisingly, came to be named toluene. 

Monosubstitution can occur at any one of the six equivalent carbons of the ring. Most of the monosubstituted benzenes have common names such as toluene (methylbenzene), phenol (hydroxybenzene), and aniline (aminobenzene). 

Aromatic substances, more than any other class of organic compounds, have acquired a large number of nonsystematic names. The use of such names is discouraged, but 1UPAC rules allow for some of the more widely used ones to be retained (Table 15.1). Thus, methylbenzene is known commonly as toluene hydroxybenzene, as phenol ami nobenzene, as aniline and so on. 

Note in the second and third examples showm that -phenol and -toluene are used as the parent names rather than -benzene. Any of the monosubstituted aromatic compounds shown in Table 15.1 can serve as a parent name, with the principal substituent (-OH in phenol or -CHj in toluene) attached to Cl on the ring. 

Problem 16.1 Monobromination of toluene gives a mixture of three bromotoluene products. Draw and name them. 

Trinitrotoluene, TNT, is a well-known explosive, (a) Using the structure available on the Web site, determine the systematic name for TNT. (b) TNT is made by nitrating toluene (methylbenzene) with a... 

C, which leads to a break in the pressure-composition curve at BF3 Ir = 2 1. The formation of the 1 1 complex in solution is indicated by titrations. Insertion of InCl into the Fe—Fe bond in boiling dioxane yields [T7 -C CO)2Fe]2lnCl in 55% yield. The only group-VIIA compound that forms an addition compound with a group-lIIB halide, namely with BF3, is [(i7 -Cp)2ReH]The formation of (t -Cp),ReH BF3 is established when (T7 -Cp),ReH is titrated tensimetrically in toluene with BF3 at 0°C. 

When the two groups in disubstituted benzenes are different, the same three isomers are possible that are possible when the substituents are the same. Compounds with two different substituents are usually named as positional derivatives of a monosubstituted (parent) compound. Above, the common (and commercial) name for methylbenzene is toluene, and the chlorinated derivatives are named as shown above. However, the same two chlorinated derivatives can also be properly named 2-chloromethylbenzene and 4-chloromethylbenzene. In this case, for naming, the parent compound is methylbenzene and it is understood that the methyl group is in the 1-position. The terms ortho- (1,2-), meta- (1,3-), and para- (1,4-) are also sometimes used for example, 2-chlorotoluene can be called ortho-c Aoioio -uene. This can be very confusing, but in the chemical industry, outside of the research labs, the common names for the parent compounds are almost always used. 

With trisubstitution by the same or different substituents, the three positional isomers shown above are possible. When the substituent groups are the same, the positional numbers are given followed by the suffix tri-. For example, if the three groups are chlorine, the first isomer above is named 1,2,3-trichlorobenzene. The compound above with different substituents is named as a derivative of the parent compound toluene (methylbenzene) where it is understood that the methyl group is in the 1-position. 

In a recent study, poly(aryl ether) dendritic branches terminated with triethyleneglycol chains were attached to Cgg [66] dendrimer 32 represents the fourth generation. The photophysical properties of these fullerodendrimers have been systematically investigated in three solvents, namely toluene, dichloromethane, and acetonitrile. On increasing dendrimer generation, it has been found that in each solvent (i) the maximum of the fullerene fluorescence band is red-shifted... 

P 23] The nitration of two standard aromatic compounds, namely benzene and toluene, was performed utilizing nitric acid/sulfuric acid mixtures and the pure... 

Applications Caceres et al. [114] compared various methods for extraction of Tinuvin 770 and Chimas-sorb 944 from HDPE pellets, namely room temperature diffusion in CHC13 (20 % extraction), ultrasonica-tion (20% extraction), Soxtec extraction with DCM (nonsolvent) (50 % extraction), dissolution (dichloroben-zene)/precipitation (2-propanol) (65-70% recovery) and boiling under reflux with toluene (solvent) at 160 °C (95 % extraction). By changing conditions (nature of solvent, T, t) similar comparisons do not have much added value. Table 3.6 compares the results of reflux extraction and MAE for additives in LDPE [115]. 

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