1-Chloro-3-ethylbenzene

Benzyl chloride undergoes further chlorination to give di- and tri-chloro derivatives, though it is possible to control the extent of chlorination by restricting the amount of chlorine used. As indicated above, it is easier to mono-brominate than it is to mono-chlorinate. The particular stabilization conferred on the benzylic radical by resonance is underlined by the reaction of ethylbenzene with halogens. 

Laali et al.234 have developed a method to the highly selective pura-adamantylation of arenes (toluene, ethylbenzene, anisole) with haloadamantanes (1-chloro- and 1-bromoadamantane, l-bromo-3,5,7-trimethyladamantane) and 1-adamantanol promoted by triflic acid in butylmethylimidazolium triflate [BMIM][OTf] ionic liquid. In contrast to reactions mn in 1,2-dichloroethane, little or no adamantane byproduct was detected in [BMIM][OTf. Furthermore, no isomerization of para-tolyladamantane was observed supporting the intramolecular nature of the formation of meta isomers. In competitive experiments with benzene-toluene mixture (1 1 molar ratio), high substrate selectivities were found (kT/kB = 16-17) irrespective of the alkylating agent. This is in sharp contrast to values about unity measured in 1,2-dichloroethane. 

Draw the structures of the following compounds (a) 3-ethyl-4-methyl-2-hexanone (b) 2-chloro-buytl acetate (c) ethylbenzene id) 3-ethylcyclohexene (e) 2-methyl-3-pentanol (/) 2-methylpropyl methyl ether. 

The inifer technique is specific for cationic and radical polymerizations. The most frequently used inifers in the first case are 1-chloro-l-methyl-ethylbenzene (a) 1,4-bis( 1-chloro-l-methylethyl)benzene (6) and l,3,5-tris(l-chloro-l-methyl)benzene (c)... 

When protons are on different carbons, it usually is straightforward to determine whether they are chemically equivalent on the basis of symmetry. Geminal protons (those on the same carbon, as in CH2) can be more subtle. Consider the protons of ethylbenzene (C6H5CH2CH3) and of its 3-bromo- 3-chloro derivative (C6H5CH2CHClBr). Rotation about the saturated C-C bond creates three rotamers for each molecule, which may be represented by the Newman projections shown in 4-10 and 4-11. For 4-10, the three rotamers... 

---