GB1007017A - 2-styrylbenzoxazole brighteners - Google Patents

Abstract

Lacquers and plastics based on chlorinated rubber, polyvinyl chloride, polystyrene and polymethyl methacrylate are brightened by addition of benzoxazole brightening agents of the formula:-wherein <FORM:1007017/C3/1> R represents hydrogen, alkyl, chloroalkyl, dichloroalkyl, hydroxyalkyl, alkoxyalkyl, aryl of less than 3 six-membered rings (optionally substituted by hydrogen, C1- 7-alkyl, C1- 7-alkoxy, hydroxy, carboxy, cyano, di-(C1- 7-alkyl) amino, C2- 8 alkanamido, C1- 7-alkylthio, C1- 7-alkylsulphonyl, carbamoyl or sulphamoyl), aralkyl, C1- 7-alkoxy, amino, C1- 7-alkylamino, di-(C1- 7-alkyl) amino and arylamino; Y represents hydrogen, C1- 7-alkoxy, halogen or C1- 7-alkyl; and n and p each individually represent zero or one, provided that their sum is either one or two.ALSO:The invention comprises optical brightening agents of the formula <FORM:1007017/C2/1> wherein R represents hydrogen, alkyl, chloroalkyl, dichloroalkyl, hydroxyalkyl, alkoxyalkyl, aryl of less than 3 six-membered rings (optionally substituted by halogen, C1-7 alkyl, C1-7 alkoxy, hydroxy, carboxy, cyano, di-(C1-7 alkyl)amino, C2-8 alkanamido, C1-7 alkyl-thio, C1-7 alkylsulphonyl, carbamoyl, or sulphamoyl), aralkyl, C1-7 alkoxy, amino, C1-7 alkyl-amino, di-(C1-7 alkyl)amino and arylamino; Y represents hydrogen, C1-7 alkoxy, halogen or C1-7 alkyl; and n and p each individually represent zero or one, provided that their sum is either one or two. The above compounds are prepared by reacting a 2-aminophenol of the formula <FORM:1007017/C2/2> with a cinnamoyl chloride of the formula <FORM:1007017/C2/3> or the corresponding bromide to give a nitro-2-cinnamamidophenol of the formula <FORM:1007017/C2/4> which is ring closed by dehydration, e.g. by fusion in boric acid, to yield a nitro-2-styrylbenzoxazole of the formula <FORM:1007017/C2/5> which is reduced to an amino-2-styrylbenzoxazole of the formula <FORM:1007017/C2/6> and subsequently mono- or di-acylated.ALSO:Cotton, resin treated cotton, nylon, acetate or woollen skeins or fabrics are invisibly marked or optically brightened by treatment with acid (e.g. acetic acid) baths, alkaline scour baths, anionic or non-ionic detergent baths commercial boundry sours, hypochlorite baths or aqueous solutions of Glaubers salt containing benzoxazole brightening agents of the formula:- <FORM:1007017/D1-D2/1> wherein R represents hydrogen, alkyl, chloroalkyl, dichloroalkyl, hydroxyalkyl, alkoxyalkyl, aryl of less than 3 six-membered rings (optionally substituted by halogen, C1-y alkyl, C1-y alkoxy, hydroxy, carboxy, cyano, di(C1-y alkyl) amino, C2-8 alkanamido, C1-y alkylthio, C1-y alkylsulphonyl, carbamoyl or sulphamoyl), aralkyl, C1-y alkoxy, amino, C1-y alkylamino, di(C1-y alkyl) amino, and arylamino; Y represents hydrogen, C1-y alkoxy, halogen, or C1-y alkyl; and n and p each individually represent zero or one, provided that their sum is either one or two.