Aromatics chlorination

The unsubstituted C-16 hydrocarbon, [2.2]paracyclophane (3), is DPXN. Both DPXC and DPXD are prepared from DPXN by aromatic chlorination and differ only in the extent of chlorination DPXC has an average of one chlorine atom per aromatic ring and DPXD has an average of two. 

Neoprene 250 Excellent mechanical properties. Good resistance to uouaromatic petroleum, fatty oils, solvents (except aromatic, chlorinated, or ketone types). Good water and alkali resistance. Fair acid resistance. 

Torlon-type polymers are unaffected by aliphatic, aromatic, chlorinated and fluorinated hydrocarbons, dilute acids, aldehydes, ketones, ethers and esters. Resistance to alkalis is poor. They have excellent resistance to radiation. If a total of 10 Mrad is absorbed at a radiation dosage of 1 Mrad/h the tensile strength decreases by only 5%. 

Replacement, of aromatic chlorine atoms, by amino groups using ammonia, 40, 97... 

Aromatic bromine compounds can be formed and transformed during various thermal processes, like aromatic chlorine compounds (ref. 22). Brominated dibenzodioxins and -furans and mixed brominated/chlorinated compounds have been detected in trace levels in the fly ash of a municipal waste incinerator (ref. 23).Chlorine is generally abundant compared to the bromine of typical municipal waste the chlorine vs. bromine ratio is in the range of 250 1. 

Aromatics, chlorinated hydrocarbons, lower alcohols, ketones, esters Alcohol, benzene, chlorinated hydrocarbons, esters, ether Alcohol, esters, ketones, dioxane... 

Figure 3 Debenzylation of a pharmaceutical intermediate containing benzyl ether and aromatic chlorine.

S. Y Wang, and J. P. Chen et al., Selective Debenzylation in the Presence of Aromatic Chlorine on Pd/C Catalysts Effects of Catalyst Types and Reaction Kinetics , paper presented at 20th Organic Reactions Catalysis Society Meeting, March 21-25, 2004, Hilton Head Island, SC, USA. 

Selective Debenzylation in the Presence of Aromatic Chlorine on Pd/C Catalysts Effects of Catalyst Types and Reaction Kinetics... 

Note that the competitive aromatic chlorination of the aromatic donors effected by the strongly oxidizing antimony pentachloride (in equation 37) is circumvented by the use of the mild Et30+SbCl[Pg.244]

A limited degree of regioselectivity of aromatic chlorination in surfactant solutions has been observed (Jaeger and Robertson, 1977). Somewhat similar observations were made by Onyivruka et al. (1983) who also used n.m.r. spectroscopy to probe the substrate orientation, and they concluded that it controlled regioselectivity. 

Solvents Good behaviour up to 60°C except with aromatics, chlorinated solvents, certain oxidants... 

Aiyl fluorides and iodides cannot be prepared by direct halogenatlon. The cyano group cannot be Introduced by nucleophilic substitution of of Aromatic chlorine in chlorobenzene but cyanobenzene can be easily obtained from diazonium salt. 

TEES is capable of treating several classes of organic compounds, including aliphatics, aromatics, chlorinated aliphatics and aromatics, polycyclic aromatics, cyanides, amines, phenolics, organic acids, and ketones. 

Sodium fluoride does not effect any replacement of aromatic chlorine atoms with fluorine, unless they are activated by substitution of electron-withdrawing groups in the ring. Several examples are reported for heterocyclic compounds. 

A catalytic amount of tetraphenylphosphonium bromide is required for the preparation of 3,4-difluorobenzoyl fluoride (11) from 3,4-dichlorobenzoyl chloride (9) with potassium fluoride.32 While 11 is formed only in 23% yield, the partially fluorine substituted intermediate 10 can be treated again with potassi um fluoride and tetraphenylphosphonium bromide at 230 °C for 10 h. In this way besides the chlorine atom of the acid chloride in 9 both the aromatic chlorine atoms are also displaced.32... 

Amines, Condensation With Aromatic Chlorine Compounds. Amines can be condensed with aromatic Cl den vs and the resulting compds... 

For an extensive discussion of the use of zeolites for catalysis of aromatic chlorinations see L. Delaude and P. Laszlo, J. Org. Chem., in press. We thank Professor Laszlo for a preprint of this publication. 

For the various matrices that were studied, specifically the sludge/fly ash, river sediment and shale rock, certain modifiers were more effective that others in terms of achieving high extraction efficiencies. For the target analytes (PCB s, aromatics, chlorinated aromatics and hydrocarbons) propylene carbonate and benzene achieved the highest extraction efficiencies compared to pure CO2. 

Jardim, W., Moraes, S., and Takiyama, M., Photocatalytic degradation of aromatic chlorinated compounds using Ti02 toxicity of intermediates, Water Res., 31, 1728, 1997. 

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