St Andrews Research Repository

St Andrews University Home
View Item 
  •   St Andrews Research Repository
  • Chemistry (School of)
  • Chemistry
  • Chemistry Theses
  • View Item
  •   St Andrews Research Repository
  • Chemistry (School of)
  • Chemistry
  • Chemistry Theses
  • View Item
  •   St Andrews Research Repository
  • Chemistry (School of)
  • Chemistry
  • Chemistry Theses
  • View Item
  • Login
JavaScript is disabled for your browser. Some features of this site may not work without it.

Reactions of some secondary and tertiary o-nitroaniline derivatives with bases

Thumbnail
View/Open
PamelaCollinsPhDThesis.pdf (32.03Mb)
Date
1957
Author
Collins, Pamela Ann
Supervisor
Smith, D. M.
Funder
Committee of Vice-Chancellors and Principals of the Universities of the United Kingdom
University of St Andrews
Metadata
Show full item record
Altmetrics Handle Statistics
Abstract
In chapter 1, a brief account of the chemical and physical properties of benzimidazole A-oxides is given. The scope and limitations of a method recently developed for the synthesis of the N-oxides from substituted o-nitroaniline derivatives are discussed. Chapter 2 discusses the reactions in the literature which are relevant to those being investigated. Chapter 3 describes the efforts made to investigate the involvement of the activatuig' groups of the o-nitroaniline derivatives in the reaction pathway. In chapter 4 the reactions of N-(4 and/or 6-substituted o-nitrophenyl) glycine and sarcosine esters with bases are described. All of the 4-substituted glycine esters and those with fluorine, acetamido and methyl on C-6 cyclized 'normally' to the corresponding NH-benzimidazole N'-oxides whereas those with chlorine, trifluoromethyl, and nitro on C-6 reacted 'abnormally' to give, in addition, such products as 1-hydroxy-quinoxaline-2,3-diones and diaminoazoxybenzenes. All of the sarcosine esters reacted 'abnormally' producing none of the N-methylbenzimidazole N'-oxides. Surprisingly they did form products indicating loss of the W-methyl group, e.g. quinoxalin-2-ones. The aldol-type condensation mechanism that has been previously applied to the syntheses of benzimidazole N-oxides does not explain these new results; they suggest that the presence of an amino-hydrogen in the starting material is necessary for N-oxide formation. An alternative mechanism is proposed which takes this possibility and the types of products formed into account. It involves the formation of an oxadiazine intermediate which can then react in a number of different ways to give the observed products. The reasons for some neighbouring substituents affecting the reaction pathway appears to be largely steric though there may also be an electronic factor. Chapter 5 contains a discussion of how the alternative mechanism could be applied to a number of other cyclizations of carbocyclic and heterocyclic compounds which involve interaction of a nitro group with a potentially nucleophilic ortho-substituent.
Type
Thesis, PhD Doctor of Philosophy
Collections
  • Chemistry Theses
URI
http://hdl.handle.net/10023/15296

Items in the St Andrews Research Repository are protected by copyright, with all rights reserved, unless otherwise indicated.

Advanced Search

Browse

All of RepositoryCommunities & CollectionsBy Issue DateNamesTitlesSubjectsClassificationTypeFunderThis CollectionBy Issue DateNamesTitlesSubjectsClassificationTypeFunder

My Account

Login

Open Access

To find out how you can benefit from open access to research, see our library web pages and Open Access blog. For open access help contact: openaccess@st-andrews.ac.uk.

Accessibility

Read our Accessibility statement.

How to submit research papers

The full text of research papers can be submitted to the repository via Pure, the University's research information system. For help see our guide: How to deposit in Pure.

Electronic thesis deposit

Help with deposit.

Repository help

For repository help contact: Digital-Repository@st-andrews.ac.uk.

Give Feedback

Cookie policy

This site may use cookies. Please see Terms and Conditions.

Usage statistics

COUNTER-compliant statistics on downloads from the repository are available from the IRUS-UK Service. Contact us for information.

© University of St Andrews Library

University of St Andrews is a charity registered in Scotland, No SC013532.

  • Facebook
  • Twitter