Patent GB-767780-A (GB)
Title: Improvements in trans n-carbamylamic esters
IPC: C07C275/50
Filed: 1954-10-29
Abstract: The invention comprises (1) the preparation of esters of trans-olefinic N-carbamylamic acids of the formula <FORM:0767780/IV(a)/1> (A is H or hydrocarbon group and the spare valencies are joined to H or acyclic hydrocarbon groups) by treating the corresponding cis-esters (see Specification 766,605) with an isomerizing agent consisting of aluminium chloride, a strong mineral acid or a non-tertiary amine; (2) the preparation of the above esters by carrying out the process of Specification 766,605 (i.e. reaction of the corresponding N-carbamyl-imide with a compound containing a non-tertiary alcoholic group) in the presence of such an isomerizing agent; and (3) the esters of the above trans-acids with aliphatic polyhydric alcohols.  Suitable isomerizing catalysts, apart from aluminium chloride, are sulphuric, hydrochloric and hydrobromic acids, and piperidine.  Specified polyhydric alcohols are cellulose, polyvinyl alcohol and partial ethers and esters thereof, alkyd resins having terminal hydroxyl groups, polymeric alcohols obtained by oxidizing and then partially reducing iso-olefin/conjugated diolefin copolymers, condensation polymers of methylol phenols and alcohols made from a glycol and divinyl sulphone.  Specification 740,591 also is referred to.ALSO:The invention comprises (1) the preparation of esters of trans-olefinic N-carbamylamic acids of the formula <FORM:0767780/IV(b)/1> (A is H or hydrocarbon group and the spare valencies are joined to H or acyclic hydrocarbon groups) by treating the corresponding cis-esters (see Specification 766,605) with an isomerizing agent consisting of aluminium chloride, a strong mineral acid or a non-tertiary amine; (2) the preparation of the above esters by carrying out the process of Specification 766,605 (i.e. reaction of the corresponding N-carbamyl-imide with a compound containing a non-tertiary alcoholic group) in the presence of such an isomerizing agent ; and (3) the esters of the above trans-acids with aliphatic polyhydric alcohols.  The N-carbamyl-imides are made as in Specification 740,591.  The reactions are preferably carried out in a solvent which may be in excess of the alcohol used.  Suitable isomerizing catalysts, apart from aluminium chloride, are sulphuric, hydrochloric and hydrobromic acids, and piperidine.  Examples show the preparation of methyl, b -chloroethyl and b -nitrobutyl N-carbamyl-fumaramates by direct esterification and of methyl, b -chloroethyl, b -hydroxyethyl, isopropyl and n-butyl N-carbamyl-fumaramates by isomerization of the corresponding cis-esters.  Additional products and starting materials are mentioned (derived from fumaramic, mesaconamic, a -ethyl-fumaramic and dimethyl fumaramic acids) in which A is hydrogen, methyl, n-butyl, t.-butyl, cyclohexyl or phenyl and the esterifying alcohol is an alkanol (up to C18), an unsaturated alcohol or an alcohol substituted by halogen, alkoxy, cyano, carboxylic acid or ester groups.  Other typical esterifying alcohols are cyclohexanol, benzyl alcohol, triethanolamine, ethylene glycol, trimethylene glycol, polyethylene glycols, glycerol, pentaerythritol, starch, glucose, sucrose, sorbitol, glycerides (e.g. castor oil), methylol-phenols, N-methylol-maleimide, N : N1-dimethylol-urea and the alcohols made from a glycol and divinyl sulphone.