The present invention relates to azo dyes of formula (1), wherein D is a radical of formula (2) or (3), R.sub.1 and R.sub.2 independently denote hydrogen; C.sub.6-C.sub.10aryl which is unsubstituted or substituted by cyano, carboxy, hydroxy, halogen, C.sub.1-C.sub.6alkyl, or C.sub.1-C.sub.6alkoxy; C.sub.1-C.sub.12alkyl which may be interrupted one or more times by —O—, —S—, —NR.sub.4—, —CO—, —COO— or —OOC—, and is unsubstituted or substituted by cyano, carboxy, hydroxy, C.sub.6-C.sub.10aryl, or C.sub.6-C.sub.10aryloxy, which C.sub.6-C.sub.10aryl or C.sub.6-C.sub.10aryloxy is unsubstituted or substituted by cyano, carboxy, hydroxy, halogen, C.sub.1-C.sub.6alkyl, or C.sub.1-C.sub.6alkoxy; R.sub.3 and R.sub.4 are each independently of the other hydrogen, halogen, nitro, cyano, trifluoromethyl, carboxy, C.sub.1-C.sub.6alkyl, C.sub.1-C.sub.6alkoxy, C.sub.1-C.sub.6alkylcarbonyl, C.sub.6-C.sub.10arylcarbonyl, C.sub.1-C.sub.6alkoxycarbonyl, C—C.sub.6alkylsulfonyl, C.sub.1-C.sub.6alkylsulfonylamino or C.sub.1-C.sub.4alkanoylamino; and R.sub.5 is halogen, nitro, cyano, trifluoromethyl, carboxy, C.sub.1-C.sub.6alkyl, C.sub.1-C.sub.6alkoxy, C.sub.1-C.sub.6alkylcarbonyl, C.sub.6-C.sub.10arylcarbonyl, C.sub.1-C.sub.6alkoxycarbonyl, C.sub.1-C.sub.6alkylsulfonyl, C.sub.1-C.sub.6alkylsulfonylamino or C.sub.1-C.sub.4alkanoylamino; and R.sub.6, R.sub.7, R.sub.8 and R.sub.9 independently of each other are hydrogen, hydroxy, halogen, cyano, nitro or C.sub.1-C.sub.4alkanoylamino, and the radicals X independently denote N or C—H, with the proviso that at least one radical X denotes C—H, which are distinguished by their good lightfastness properties.

##STR00001##

Disclosed is an azo compound represented by Formula (I)

##STR00001##

in which R.sup.1 is hydrogen or methyl, R.sup.2 is hydrogen or methyl, and R.sup.3 is hydrogen, an unsubstituted linear alkyl group of from 1 to 4 carbon atoms, or an unsubstituted branched alkyl group of from 1 to 9 carbon atoms. This disclosure also provides a black dye composition including the azo compound represented by Formula (I).

Disclosed is an azo compound represented by Formula (I), ##STR00001##
in which R.sup.1 is hydrogen or methyl, R.sup.2 is hydrogen or methyl, and R.sup.3 is hydrogen, an unsubstituted linear alkyl group of from 1 to 4 carbon atoms, or an unsubstituted branched alkyl group of from 1 to 4 carbon atoms. This disclosure also provides a black dye composition including the azo compound represented by Formula (I).

The present invention relates to azo dyes of formula (1), wherein D is a radical of formula (2) or (3), R.sub.1 and R.sub.2 independently denote hydrogen; C.sub.6-C.sub.10 aryl which is unsubstituted or substituted by cyano, carboxy, hydroxy, halogen, C.sub.1-C.sub.6alkyl, or C.sub.1-C.sub.6alkoxy; C.sub.1-C.sub.12alkyl which may be interrupted one or more times by O, S, NR.sub.4, CO, COO or OOC, and is unsubstituted or substituted by cyano, carboxy, hydroxy, C.sub.6-C.sub.10 aryl, or C.sub.6-C.sub.10 aryloxy, which C.sub.6-C.sub.10 aryl or C.sub.6-C.sub.10 aryloxy is unsubstituted or substituted by cyano, carboxy, hydroxy, halogen, C.sub.1-C.sub.6alkyl, or C.sub.1-C.sub.6alkoxy; R.sub.3 and R.sub.4 are each independently of the other hydrogen, halogen, nitro, cyano, trifluoromethyl, carboxy, C.sub.1-C.sub.6alkyl, C.sub.1-C.sub.6alkoxy, C.sub.1-C.sub.6alkylcarbonyl, C.sub.6-C.sub.10 arylcarbonyl, C.sub.1-C.sub.6alkoxycarbonyl, C.sub.1-C.sub.6alkylsulfonyl, C.sub.1-C.sub.6alkylsulfonylamino or C.sub.1-C.sub.4 alkanoylamino; and R.sub.5 is halogen, nitro, cyano, trifluoromethyl, carboxy, C.sub.1-C.sub.6alkyl, C.sub.1-C.sub.6alkoxy, C.sub.1-C.sub.6alkylcarbonyl, C.sub.6-C.sub.10 arylcarbonyl, C.sub.1-C.sub.6alkoxycarbonyl, C.sub.1-C.sub.6alkylsulfonyl, C.sub.1-C.sub.6alkylsulfonylamino or C.sub.1-C.sub.4 alkanoylamino; and R.sub.6, R.sub.7, R.sub.8 and R.sub.9 independently of each other are hydrogen, hydroxy, halogen, cyano, nitro or C.sub.1-C.sub.4 alkanoylamino, and the radicals X independently denote N or CH, with the proviso that at least one radical X denotes CH, which are distinguished by their good lightfastness properties. ##STR00001##

Described herein is a method of dyeing the hair. The method includes applying to the hair a hair color composition including one or more direct dye compounds and rinsing the hair with water. The one or more direct dye compounds each include a blue-violet or blue chromophore, one or two permanent cations, one to four incipient cations, and one or more hydrophobic moieties. The incipient cations are pendant to the core structure and are neutral. The direct dye compounds enter the hair shaft after the hair color composition is applied to the hair. The hair color composition has a pH of from about 6 to about 11. The pH of the hair after rinsing is from about 3.5 to about 6. The rinsing of the hair causes one or more of the one to four incipient cations to change from neutral to positively charged inside of the hair shaft.

A family of covalent kinetic stabilizer compounds that selectively and covalently react with the prominent plasma protein transthyretin in preference to more than 4000 other human plasma proteins is disclosed. A contemplated compound corresponds in structure to Formula I, below, where the various substituents are defined within, and ##STR00001##
reacts chemoselectively with one or two of four Lys-15 -amino groups within the transthyretin tetramer. The crystal structure confirms the binding orientation of the compound substructure and the conjugating amide bond. A covalent transthyretin kinetic stabilizer exhibits superior amyloid inhibition potency, compared to a non-covalent counterpart, and inhibits cytotoxicity associated with amyloidogenesis.

A family of covalent kinetic stabilizer compounds that selectively and covalently react with the prominent plasma protein transthyretin in preference to more than 4000 other human plasma proteins is disclosed. A contemplated compound corresponds in structure to Formula I, below, where the various substituents are defined within, and

##STR00001##

reacts chemoselectively with one or two of four Lys-15 -amino groups within the transthyretin tetramer. The crystal structure confirms the binding orientation of the compound substructure and the conjugating amide bond. A covalent transthyretin kinetic stabilizer exhibits superior amyloid inhibition potency, compared to a non-covalent counterpart, and inhibits cytotoxicity associated with amyloidogenesis.