Benzylation, toluene

Chlorinated paraffins. Chlorinated ben2enes. Ring-chlorinated toluenes. Benzyl chloride. 

Benzyioxycarbonyi chioride (Cbz-Ci, benzyi cbioroformate) [501-53-1] M 170.6, b 103 /20mm, d 1.195, n 1.5190. Commercial material is better than 95% pure and may contain some toluene, benzyl alcohol, benzyl chloride and HCl. After long storage (e.g. two years at 4 , Greenstein and Winitz [The Chemistry of the Amino Acids Voi 2 p. 890, J Wiley and Sons NY, 1961] recommended that the liquid should be flushed with a stream of dry air, filtered and stored over sodium sulfate to remove CO2 and HCl which are formed by decomposition. It may further be distilled from an oil bath at a temperature below 85 because Thiel and Dent [Annalen 301 257 1898] stated that benzyioxycarbonyi chloride decarboxylates to benzyl chloride slowly at 100 and vigorously at 155 . Redistillation at higher vac below 85 yields material which shows no other peaks than those of benzyioxycarbonyi chloride by NMR spectroscopy. LACHRYMATORY and TOXIC. 

Benzol hjthiophene, see Naphthalene 1,2,3-Benzotriazin-4 (3/J -one, see Azinnhos-methyl Benzotriazole, see Tetrachloroethylene Benzyl alcohol, see Benzo[a]anthracene, Benzyl butyl phthalate. Benzyl chloride, Permethrin. o-Xylene, m-Xylene, p-Xylene. Toluene 0-Benzyl alcohol, see o-Xylene m-Benzyl alcohol, see m-Xylene p-Benzyl alcohol, see p-Xylene 10-Benzyl-10-hydroanthracen-9-one, see Benzo [ a] anthracene Benzyl hydroperoxide, see Toluene Benzyl nitrate, see Toluene Benzylsuccinic acid, see Toluene... 

Toluene Benzyl alcohol Benzaldehyde Benzoic acid... 

Mikhailova TV Comparative toxicity of chloride derivatives of toluene—benzyl chloride, benzal chloride and benzotrichloride. Fed Proc 24 T877-800, 1965... 

Side-Chain Chlorination of Toluene. Benzyl chloride, used mainly in the manufacture of plasticizers, may be prepared by the thermal or photochemical chlorination of toluene.191,192 In the thermal process chlorine is passed through toluene at 65-100°C. To minimize the formation of benzal chloride and benzotrichloride, the conversion is limited to about 50%. Since the density of the reaction mixture increases linearly with the formation of benzyl chloride,145 measurement of density is used to monitor the progress of the reaction. The overall yield based on toluene is about 90%, and the maximum conversion to benzyl chloride is above 70%. Higher yields in photochemical chlorination may be achieved. 

The impurities present after chlorination are unchanged toluene, benzyl chloride and benzotrichloride. 

T.V. Mikhailova, Comparative toxicity of chloride derivatives of toluene benzyl chloride, benzal chloride, and benzotrichloride. Gig. Tr. Prof. Zabol. 8 14, 1965. 

When toluene, benzyl alcohol, and a,a-dimethylbenzyl alcohol are solvated with either water or ammonia and ionized (I - <- S0), a number of reactions... 

P-450 amine dealkylation mechanisms. Because kn/ko values for A -demethylation of / -substituted A, A -dimethylanilines by cytochrome P-450 are nearly identical with those for the hydrogen abstraction reactions of t-BuO , it was proposed that P-450 reacted by a direct hydrogen-atom-abstraction mechanism (B) rather than a sequential electron-proton-electron-transfer mechanism (A) [78, 80]. Identical relationships between A h/ d values for reactions of t-BuO and P-450 has been expanded for other substrates including />-xylene, toluene, benzyl alcohol, and tertiary trialkylamine [78]. It has thus been suggested that all these P-450 reactions proceed by a common hydrogen-atom transfer mechanism [78]. 

In the aromatic series it is observed that the introduction of a halogen atom into the side chain of a substance confers lachrymatory properties, while if it replaces a hydrogen atom from the benzene nucleus, a substance results which has no physiopatho-logical properties. Thus, from toluene, benzyl bromide, CgHj—CHjBr, is obtained in the first case. This has energetic lachrymatory properties, while bromotoluene, CgH4Br—CH3, has no toxic action. 

Toluene Benzyl chloride Benzal chloride Benzotrichloride... 

Wolczanski also investigated the chemistry of a tantalum imido system. In this system, elimination of hydrocarbon from the bis-amido imido complex occurs with difficulty at 183°C to give an amido bis-imido complex. The elimination is reversible, with the bis-imido species not being directly observed (Scheme 10). Under methane pressure, the phenyl complex loses benzene and adds methane. Neopentane, benzene, and toluene (benzylic activation) were also found to undergo activation, but not cyclohexane. The authors conclude from their equilibrium studies that the differences in metal-carbon bond strengths are approximately equal to the differences in carbon-hydrogen bond... 

Silica-supported polytrifluoromethanesulfosiloxane (Si02-Si-SCF3) has been prepared by Jiang et al., and has been used to catalyze the Friedel-Crafts benzylation of arene with benzyl alcohol [124]. The selectivity of the reaction was influenced by catalyst concentration, reaction time and arene/benzyl alcohol molar ratios. In the range 30 1 to 10 1 of toluene/benzyl alcohol molar ratios, the yield of alkylated product was quantitative, but with a molar ratio of 5 1, 37% the intramolecular condensed product, dibenzyl ether, was formed (Scheme 5.23). 

A decline in catalytic activity with use was detected for reactions catalyzed by either species. Polymers 2 and 7 in the absence of cobalt both revealed excellent stability at 190 C (hydroformylation temperatures). This is illustrated by the TGA curves shown in Figure 4. Curve A shows an onset of decomposition for phosphinated polyphosphazene of 400 C, slightly better than that of phosphinated polystyrene (curve B, 20Z crosslinked curve C, 2Z crosslinked). Loss of phosphorus was observed over a period of 45 hours for a catalyst derived from 2 (2Z DVB crosslinked). The data depicted in Figure 5 reveal benzene, toluene, benzyl alcohol, diphenylphosphine and triphenyl phosphine as cleavage products. If one recalls the previously discussed homogeneous results it should be clear that the PPho is derived from a phosphide intermediate such as 8. ... 

This reaction was initially studied by von Baeyer in 1872. It is an acid-catalyzed condensation of aromatic compounds with formaldehyde or formaldehyde derivatives. In normal conditions, the reactive benzene derivatives such as phenols and arylamines are applied to condense with formaldehyde however, a small number of less-reactive aromatics have also been used in this reaction, including benzene, toluene, benzyl chloride,biphenyl, iodobenzene, naphthalene, and mesitylene. Although no yields were given in the early studies, it is reasonable to obtain 70-80% yield for this type of reaction. Many other reactions have been developed to synthesize diarylmethanes, including Katritzky s benzotriazole method, Kochi s dealkylative coupling," Fukuzaw s 1,3-propandiol method, and the reduction method. In general, the condensation occurs at the /tflra-position of substituted aromatics. 

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