Patent GB-853129-A (GB)
Title: New pyrrolo derivatives and process for their manufacture
IPC: C07D263/62
Filed: 1957-07-31
Abstract: Optical brightening agents suitable for incorporation in spinning compositions, e.g. of synthetic linear polyamides, or in an acetylcellulose solution to be used for spinning are of the formula: <FORM:0853129/IV(a)/1> in which A is a benzene nucleus which may be substituted, of which two vicinal carbon atoms are bound to the imidazole nitrogen atoms; R and R1 are hydrogen or the same or different substituents; and R2 is hydrogen, an acyl group, or a substituted or unsubstituted alkyl, alkenyl, cycloalkyl, aryl, aralkyl or heterocyclic residue; or salts or quaternary ammonium salts thereof.ALSO:The invention comprises the pyrrole derivatives of the formula:  <FORM:0853129/IV(b)/1> in which A is a benzene nucleus (which may be substituted, e.g. by halogen atoms, or alkyl, alkoxy or sulphonic acid groups) of which two vicinal carbon atoms are bound to the imidazole nitrogen atoms ; R and R1 are hydrogen or the same or different substituents, e.g. araliphatic groups, alkyl, alkenyl or hydroxyalkyl groups containing up to 3 carbon atoms, or aromatic or heterocyclic groups ; and R2 is hydrogen, an acyl group, or a substituted or unsubstituted alkyl, alkenyl, cycloalkyl, aryl, aralkyl or heterocyclic group ; and salts and quaternary salts thereof.  These compounds may be prepared by reacting ammonia or an agent yielding ammonia, (such as urea), or a suitable primary amine, with a compound of formula :  <FORM:0853129/IV(b)/2> or a salt thereof, and, if desired, acylating when R2 is hydrogen ; alkylating, hydroxyalkylating, alkenylating, or aralkylating when R and/or R1 is hydrogen ; and/or sulphonating in the benzene nucleus ; and, if desired, converting into a quaternary ammonium salt.  The starting benzimidazole compounds may be prepared by reacting an o-diaminobenzene, of which one amino group is primary and the other primary or secondary, or a salt thereof, with a hydroxyacid of formula :  <FORM:0853129/IV(b)/3> or a functional derivative thereof, and if desired alkylating, hydroxyalkylating, alkenylating or aralkylating.  The compounds of the invention exhibit fluorescence and may be used as optical brightening agents, for rendering organic materials opaque to ultra-violet rays, and as intermediates for the manufacture of dyestuffs.ALSO:Optical brightening agents suitable for addition to dyebaths or bleaching baths or for admixture with dyestuffs or dressing agents (such as starches or synthetic dressings, e.g. anti-crease dressings) are of the formula: <FORM:0853129/IV (c)/1> in which A is a benzene nucleus, which may be substituted, of which two vicinal carbon atoms are bound to the imidazole nitrogen atoms; R and R1 are hydrogen or the same or different substituents; and R2 is hydrogen, an acyl group, or a substituted or unsubstituted alkyl, alkenyl, cycloalkyl, aryl, aralkyl or heterocyclic group; and salts and quaternary ammonium salts thereof.  The compounds may be applied in aqueous solution or dispersion or in solution in organic solvents.  Materials which may be treated include protein fibres such as wool, acetylcellulose fibres, cellulose fibres, e.g. paper pulp, polyamide fibres such as nylon, and polyacrylonitrile fibres.  In examples, polyacrylonitrile fibres are treated with 2, 5- di-[benzimidazyl-(2)]-pyrrole in a bath containing formic acid; undyed cellulose textiles are washed in a bath containing 2, 5- di-[benzimidazyl-(2)]-pyrrole and the sodium salt of 2- heptadecyl -N- benzylbenzimidazyl disulphonic acid; and protein fibres, acetyl-cellulose fibres or polyamide fibres are treated with a solution containing ammonium hydroxide and the imidazolium compound obtained from methylated 2, 5- di-[benzimidazyl-(2)]-pyrrole and dimethyl sulphate.ALSO:Detergent compositions contain, as optical brightening agents, compounds of the formula:  <FORM:0853129/III/1> in which A is a benzene nucleus, which may be substituted, of which two ricinol carbon atoms are bound to the imidazole nitrogen atoms; R and R1 are hydrogen or the same or different substituents; and R2 is hydrogen, an acyl group, or a substituted or unsubstituted alkyl, alkenyl, cycloalkyl, aryl, p aralkyl or heterocyclic group; or salts or quaternary ammonium salts thereof.  Suitable detergents are soaps, soap-like substances, salts of sulphonated compounds, e.g. sulphonated benzimidazoles substituted at the 2-carbon atom by a higher alkyl radical, salts of monocarboxylic acid esters of 4-sulphophthalic acid with higher fatty alcohols, salts of fatty alcohol sulphonates, alkyl-aryl-sulphonic acids, condensation products of higher fatty acids with aliphatic hydroxy- or amino-sulphonic acids, polyglycol ethers derived from ethylene oxide and a higher fatty alcohol, alkyl-phenol or fatty amine, sulphate cellulose waste liquor, or condensation products of formaldehyde with naphthalene sulphonic acids, which may be alkylated.