Part One: Ortho-Hydroxylation of Phenols. Part Two: Dibenz(b,f)Oxepins with an Addendum on Dibenz(b,f)Thiepins

Summers, Lindsay A (1955) Part One: Ortho-Hydroxylation of Phenols. Part Two: Dibenz(b,f)Oxepins with an Addendum on Dibenz(b,f)Thiepins. PhD thesis, University of Glasgow.

Abstract

Part One: Ortho-Hydroxylation of Phenols Phenol and its homologues are condensed with 2-chloro-3,5-dinitrobenzophenone giving 2-aryloxy-3,5-dinitrobenzophenones. These are hydroxylated in concentrated sulphuric acid by treatment with acetic acid and hydrogen peroxide affording 2-(2"-hydroxyaryloxy)-3,5-dinitrobenzophenones which, by renewed hydroxylation yield 2-(2",6"-dihydroxyaryloxy)-3,5-dinitrobenzophenones. Scission of the mono-hydroxylated products leads to catechol and its homologues; scission of the di---hydroxylated products yields pyrogallol and its homologues. The requisite cleavage is more reliably effected by phenylhydrazine than by piperidine. Part Two: Dibenz (b,f) oxepins 5-Nitro-2-phenoxybenzaldehyde, prepared from phenol in reaction with 2-chloro-5-nitrobenzaldehyde, is converted by standard methods into 5-nitro-2-phenoxyphenyl-pyruvic and -acetic acids. Each of these acids is cyclised by polyphosphoric acid to the appropriate derivative, of 2-nitrodibenz(b,f)oxepin. Hence, or from modified intermediates, there are prepared the parent compound, namely dibenz(b,f)oxepin and its 2-nitro-derivative. Incidentally, some aspects of the chemistry of this class of compound have been examined and the study has been extended to include members which incorporate certain structural features found in the alkaloid, cularine. In an addendum the similar synthesis of dibenz (b,f)- thiepin derivatives from 5-nitro-2-(p-tolyithio)benzaldehyde is described and some of their transformations are discussed.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Keywords: Organic chemistry
• Date of Award: 1955
• Depositing User: Enlighten Team
• Unique ID: glathesis:1955-79166
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 05 Mar 2020 11:36
• Last Modified: 05 Mar 2020 11:36
• URI: https://theses.gla.ac.uk/id/eprint/79166