Indan and indene

Indan can be recovered by distillation of the heavy gasoline from coal tar refining. Indene, which is present in pyrolysis gasoline and in coal tar heavy gasoline, is of particular technical importance. It is polymerized with coumarone and other olefins to produce indene/coumarone resins. 

Indene/coumarone resins find extensive application, especially in the production of adhesives, as reinforcers and tackifiers in the production of commerical rubber products, and in paint manufacture. Production of indene-derived resins in Western Europe is around 110,000 tpa. 

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Ethyltoluene is manufactured by aluminum chloride-cataly2ed alkylation similar to that used for ethylbenzene production. All three isomers are formed. A typical analysis of the reactor effluent is shown in Table 9. After the unconverted toluene and light by-products are removed, the mixture of ethyltoluene isomers and polyethyltoluenes is fractionated to recover the meta and para isomers (bp 161.3 and 162.0°C, respectively) as the overhead product, which typically contains 0.2% or less ortho isomer (bp 165.1°C). This isomer separation is difficult but essential because (9-ethyltoluene undergoes ring closure to form indan and indene in the subsequent dehydrogenation process. These compounds are even more difficult to remove from vinyltoluene, and their presence in the monomer results in inferior polymers. The o-ethyltoluene and polyethyltoluenes are recovered and recycled to the reactor for isomerization and transalkylation to produce more ethyltoluenes. Fina uses a zeoHte-catalyzed vapor-phase alkylation process to produce ethyltoluenes. 

Hypothalamic amines and the release of gonadotrophins and other pituitary hormones, 8,119 Indane and indene derivatives of biological interest, 4, 163 The Inhibition of nonadrenaline uptake by drugs, 2, 1... 

Dimethylsilylene reacts with cyclooctatetraene at 550 °C to give 1-sila-indane and -indene as the main products. These are thought to result from the silacyclononatetraene, which isomerizes and aromatizes under the extreme thermal conditions by analogy with the carbon system (Scheme 23) (75TL3893). 

Experimental Thermochemistry of Heterocycles and Their Aromaticity A Study of Nitrogen, Oxygen, and Sulfur Derivatives of Indane and Indene... 

A plausible alternative (supplementary ) approach to the aromaticity of our diverse derivatives of indane and indene makes use of the deviation from thermoneutrality for the generic reaction ... 

Finally, we note that all of the discussed heterocyclic derivatives of indane and indene have heteroatoms only in their five-membered ring. There are many other heterocycles related to indane that have the heteroatoms located elsewhere. However, the thermochemistry of such species is essentially uncharted. The enthalpy of formation of purine (XLVIII), with its four nitrogens dispersed through both rings, has been measured in recent times [78], and chronicled in the archive [15] with yet a later value [79], These two values inexplicably differ by over 2000 kJ mol-1. In the absence of a value for the enthalpy of sublimation we are hesitant to discuss this species further, other than to note two estimates from a paper more than 100 years old [80] that straddle the results in [78] by ca. 20 kJ mol-1. 

Figure 2.7 contains plots of repetitive injection GC/MS chromatographic peak areas (integrated total ion current) as a function of sample temperature for benzene and styrene as well as selected products representing alkyl aromatics (ethyl benzene), indanes (methyl indane) and indenes (indene) evolved from PS-catalyst samples. The plots show that benzene is by far the most abundant volatile product. All of the PS-catalyst samples produce alkyl benzenes and indanes, however samples containing HZSM-5 catalyst generate significantly lower relative yields of these products. 

Coupling reactions. The Ph3P-complex of NU2 is found to succor the reaction of obiomohenzylzinc bromides with alkenes and alk3mes, dehvering indanes and indenes, respectively. 

To find the structures of indane and indene just retrace your steps. This compound resulted from vigorous hydrogenation of indane.(Three hydrogen molecules were added across the resonance stabilized double bonds of indane.) Therefore, the structure indane must be ... 

Petroleum- and coal-derived heavy gasoline fractions with a boiling range of around 160 to 220 °C contain polymethylated benzenes, such as trimethylbenzenes (pseudocumene, mesitylene and hemimellitene), together with the tetramethylated benzenes durene, isodurene and prehnitene. Indane and indene compounds, penta- and hexamethylbenzene and cumene, are also present in these heavy gasoline fraction. (Cumene is predominantly converted to phenol as described in Chapter 5.2). 

The manufacture of vlnyltoluene is analogous to that of styrene where toluene is substituted for benzene (Equations 1 and 2) in a conventional acid catalyzed alkylation with ethylene. The process gives rise to three Isomers during alkylation (Equation 1). The close boiling points (Table 2) of the meta and para isomers make it impractical to accomplish a separation by distillation (10). The ortho Isomer, however, is removed and recycled by a careful and costly distillation. This step is necessary because some of the ortho isomer undergoes cycllzatlon (Equation 3) during the dehydrogenation step to produce indan and Indene (11). 

Figure 23 Benzylic hydroxylations of indan and indene by P. putida.

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