Rearrangements intramolecular aromatic

Reaction CXLIX. Intramolecular Rearrangement of Aromatic Amine Sulphates.—When sulphuric acid is added to an amine a sulphate is usually formed. If the sulphate is heated either alone (baking process) or with... 

When a radical is formed in a chain four or five carbon atoms removed from an aryl group, rearrangements that amount to intramolecular aromatic substitutions can occur. The initial radical attack will yield a cyclohexadienyl radical intermediate with an attached five- or six-membered ring, as in Equation 9.109. 

Smiles rearrangement Intramolecular nucleophilic aromatic rearrangement of activated aromatic substrates. 416... 

Smiles rearrangement. Intramolecular nucleophilic aromatic substitution in alkaline solution resulting in the migration of an aromatic system from one heteroatom to another. 

For a consecutive electroeyelic ring closure Claisen rearrangement-intramolecular ami-nation process see refs 206 and 207. For studies on the sequential Claisen rearrangement of methyl-3-aryloxy-2-(aryloxymethyl)prop-2-enoates see ref 208 and for the base-catalyzed aromatic Claisen rearrangement of 3-hydroxyphenyl allyl ethers, cf. ref 209. 

Lee et al. have developed a fast and easy access to methyl ( )-2-nitromethyl-cinnamates 304 from the corresponding MBH acetates with NaN02 in DMF. Several o-chloro-2-nitromethylciimamates undergo an intramolecular aromatic substitution reaction, followed by rearrangement to yield coumarin derivatives 306 in moderate yields (Scheme 3.131). " ... 

Aromatic Substitution (Carey Sundberg, Chapter 11) Intramolecular Wittig Reaction Sigmatropic Rearrangements... 

An interesting rearrangement which is based on the intramolecular acylation of an enamine by an ester is found in the aromatization of the adduct derived from N-methylpyrrole and an acetylenedicarboxylic ester (407,408). 

The mechanism of the indolization of aniline 5 with methylthio-2-propanone 6 is illustrated below. Aniline 5 reacts with f-BuOCl to provide A-chloroaniline 9. This chloroaniline 9 reacts with sulfide 6 to yield azasulfonium salt 10. Deprotonation of the carbon atom adjacent to the sulfur provides the ylide 11. Intramolecular attack of the nucleophilic portion of the ylide 11 in a Sommelet-Hauser type rearrangement produces 12. Proton transfer and re-aromatization leads to 13 after which intramolecular addition of the amine to the carbonyl function generates the carbinolamine 14. Dehydration of 14 by prototropic rearrangement eventually furnishes the indole 8. 

Treatment of 6-arylidenehydrazino-3-alkyl-5-nitrouracils 510 with etha-nolic KOH caused a benzylic acid type of rearrangement to give 511, which were alkylated to give 512, whose cyclization with diethyl azodicar-boxylate gave (80H1295) 513 by intramolecular cycloaddition through valence isomerization and then aromatization with diethyl azodicarboxylate (Scheme 107). 

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