Aromatic compounds dibenzyl ester

The production of polysulfones was shown to be possible in Ref [ 181 ] by means of interaction of sulfuric acid, sulfur trioxide or their mixes with aromatic compounds (naphthalene, methylnaphthalene, methoxynaphtha-lene, dibenzyl ester, bisphenylcarbonate, bisphenyl, stilbene) if one used the anhydride of carbonic acid at 30-200 as the process activator. Obtained polymers could be reprocesses by means of pressing. 

On the basis of Betti s initial work, the Betti reaction has been extended to both primary amines and secondary amines. The resulting Betti amines have been applied as ligands or chiral auxiliaries in asymmetric synthesis. In addition, the Betti reaction has also been extended to the reaction among aldehydes, secondary amines, and compounds of active methylene moiety, such as dibenzyl ketones which can tautomerize to enols and mimic naphthol. Moreover, the reaction of aromatic aldoximes and 0-keto esters to afford isoxazolones should also be considered as an extension of the Betti reaction. 

The latter is known as the elimination-addition mechanism of the nucleophilic aromatic substitution. The high reactivity of aryllithiums precludes the use of several types of functional groups such as aldehydes, ketones, esters, amides, amines, alcohols, phenols, nitro-compounds, carboxylic acids etc. However, properly protected alcohols, phenols or amines can effect the reaction. Various ether protecting groups, e.g. Tr, Me, /-Pr, Bn, 4-MeOBn, are employed in the former instances, whereas A, V-dibenzyl group is convenient for the amine protection. 

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