GB835891A - New dicarboxylic acid esters and amides and process for their manufacture - Google Patents

Abstract

The invention comprises new acyl compounds of formula <FORM:0835891/IV (b)/1> in which R1 and R2 are aryl residues, -OC-R3-CO- is the residue of an unsaturated dicarboxylic acid as defined below and the -O- bridges and -NH- groups are attached to adjacent carbon atoms in the aryl nuclei. The dicarboxylic acids referred to are those that contain one or more double bonds between the two carboxylic groups. The double bonds may occur in the form of aromatic or heterocyclic rings, for example, benzene or furane rings. Of particular importance are the dicarboxylic acids in which the two carbonyl bonds of the carboxylic groups form together with the intermediate residue a continuous chain of conjugated double bonds, e.g. maleic acid, fumaric acid, terephthalic acid, thiophene-2,5-dicarboxylic acid and furane 2,5-dicarboxylic acid. The new compounds are prepared by condensing dihalides of the unsaturated acids, in inert organic solvents, with primary aryl amines which contain a hydroxyl group adjacent to the amino group. The amines may contain other substituents such as alkyl groups, halogen atoms and nitro groups. Examples are given of the preparation of <FORM:0835891/IV (b)/2> <FORM:0835891/IV (b)/3> <FORM:0835891/IV (b)/4> <FORM:0835891/IV (b)/5> <FORM:0835891/IV (b)/6> <FORM:0835891/IV (b)/7> <FORM:0835891/IV (b)/8> <FORM:0835891/IV (b)/9> <FORM:0835891/IV (b)/100> <FORM:0835891/IV (b)/111> <FORM: <FORM:0835891/IV (b)/134> and (o) <FORM:0835891/IV (b)/145> The products may be used for the production of oxazoles which are optical brightening agents by treatment with agents which split off water, as described and claimed in Specification 835,892. In this way <FORM:0835891/IV (b)/156> is obtained from compound (a) above, <FORM:0835891/IV (b)/167> from (c), <FORM:0835891/IV (b)/178> from (d), <FORM:0835891/IV (b)/189> from (e), <FORM:0835891/IV (b)/190> from (n), and <FORM:0835891/IV (b)/201> from (o).