Diphenylmethane heterocyclic

Benzene (1) is the simplest aromatic hydrocarbon upon which our knowledge of aromatic chemistry is based. This hydrocarbon, the alkylbenzenes (2), the arylmethanes [e.g. diphenylmethane (3)], the biphenyls [e.g. biphenyl (4)] and the condensed polycyclic systems [e.g. naphthalene (5) and anthracene (6)] all exhibit chemical reactivity and spectroscopic features which are markedly different from their aliphatic and alicyclic hydrocarbon counterparts. Indeed the term aromatic character was introduced to specify the chemistry of this group of hydrocarbons and their substituted functional derivatives, and it was soon used to summarise the properties of certain groups of heterocyclic compounds having five- and six-membered ring systems and the associated condensed polycyclic analogues (Chapter 8). 

Interesting possibilities of synthesis arise when elimination leads to cyclic products. Such cyclization is fairly common with aromatic compounds. The mixture of products obtained from diphenylmethane contains about 25 per cent fluorene 2S> (Table 3). Similarly, benzophenone yields about 30 per cent fluorenone 20). The same method can be applied to the synthesis of heterocyclic compounds. Diphenylamine yields up to 30 per cent carbazol 26 di-phenylether about 10 per cent dibenzofurane 16). 

Diphenylmethyl Carbanions The carbanions based on diphenylmethane (p/fj, = 32) [2] are useful initiators for vinyl and heterocyclic monomers, especially alkyl methacrylates at low temperatures [78]. 1,1-Diphenylalkyllithiums can also efficiently initiate the polymerization of styrene and diene monomers that form less stable carbanions. Diphenylmethyllithium can be prepared by the metallation reaction of diphenylmethane with butyllithium or by the addition of butyllithium to DPE as shown in Equation 7.13. This reaction can also be utilized to prepare functionalized initiators by reacting butyllithium with a substituted DPE derivative [78]. Addition of lithium salts such as lithium chloride, lithium tert-butoxide, or lithium 2-(2-methoxyethoxy)ethoxide with... 

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