Accession Number : AD0715756
Title : Persulphate Oxidation of Carboxylid Acids and Amides.
Descriptive Note : Final technical rept. Oct 69-Sep 70,
Corporate Author : ABERDEEN UNIV (SCOTLAND) DEPT OF CHEMISTRY
Personal Author(s) : Thomson,R. H.
Report Date : 31 OCT 1970
Pagination or Media Count : 26
Abstract : 2-Biphenylyloxyacetic acid and 2-(2'-biphenylyl)-2-methylpropanoic acids on treatment with potassium persulphate in hot aqueous solution underwent oxidative decarboxylation followed by cyclization giving good yields of the corresponding pyrans and smaller quantities of dimeric products. 2-(1-Napthyl)phenoxyacetic acid, by comparison, gave mainly dimeric products and a low yield of pyram. 2-(2'Methoxybiphenylyl)- and 2-(2'-ethoxybiphenylyl)- oxyacetic acids similarly gave low yields of pyrans. A minor product obtained from the latter acid and from 1,1'-biphenylylenedioxyacetic acid in 15.5% yield has been assigned a novel spirodiketone structure and is considered to arise by Diels-Alder addition of the first-formed benzo-2,3-dihydro-furan-3-spirocyclohexa-3', 5'-diene-2'-one. Evidence is presented that SO4 is the effective oxidant in these reactions and mechanisms are proposed to account for the formation of the products. Two further examples of the oxidative cyclization of biphenyl1-2-carboxamides with persulphate are reported in which cyclization occurs with elimination of the 2'-substituent giving principally 3,4-benzo-coumarin. (Author)
Descriptors : (*CARBOXYLIC ACIDS, *OXIDATION), (*OXYGEN HETEROCYCLIC COMPOUNDS, SYNTHESIS(CHEMISTRY)), (*AMIDES, OXIDATION), (*NITROGEN HETEROCYCLIC COMPOUNDS, SYNTHESIS(CHEMISTRY)), ACETIC ACID, DIENE SYNTHESIS, SULFATES, KETONES, GREAT BRITAIN
Subject Categories : Organic Chemistry
Distribution Statement : APPROVED FOR PUBLIC RELEASE