The present invention relates to novel cationic azomethine direct dyes of formula (I) and the leuco forms thereof of formula (II), and also to the use thereof for dyeing keratin fibres, in particular human keratin fibres such as the hair: (I) (II) in which formula (I) or (II) X.sub.1, X.sub.2, R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6, n and n are as defined in the description. The compounds of formula (I) according to the invention can give powerful, chromatic and sparingly selective colourings with good colour build-up, which are resistant to the various attacking factors to which keratin fibres may be subjected, such as inclement weather, light, washing and perspiration. ##STR00001##

The is provided a compound of formula I or II or physiologically acceptable salts or solvates, or oxidised derivatives thereof:

##STR00001##

where R.sup.1 to R.sup.3, R.sup.13 and R.sup.14 are as defined herein. Also disclosed herein are methods of dyeing hair or (temporarily) tattooing the skin using the compounds of formula I or II (or physiologically acceptable salts or solvates, or oxidised derivatives thereof) in a suitable composition.

An object of the present invention is to provide a compound exhibiting a cyan color having properties such as high chroma, high light fastness, and high solubility. The compound is represented by the following General Formula (1).

##STR00001##

In Formula (1), R.sub.1 R.sub.2 each independently represent a linear, branched, or cyclic alkyl group having 6 or more and 12 or fewer carbon atoms, R.sub.3 represents a 4-alkylphenyl group, a 4-halogenated phenyl group, or a 3-alkoxyphenyl group, R.sub.4 represents a linear, branched, or cyclic alkyl group having 1 or more and 8 or fewer carbon atoms, and R.sub.5 represents a linear, branched, or cyclic alkyl group having 1 or more and 8 or fewer carbon atoms or a benzyl group.

The present invention provides a plastic article containing suspended photochromic dye molecules, and the said suspended photochromic dye molecules suspended in liquid micro-droplets of a suspension medium, and the said micro-droplets of the said suspension medium containing the said suspended photochromic dye molecules are embedded inside a solid polymer matrix, and the said solid polymer matrix is formed by polymerization of liquid polymer precursors. The invented structure of a plastic article containing suspended photochromic dye molecules exhibits fast response time and enhances photochromic performance.

A coloring compound comprises a triphenylmethane structure having specific substituents.

The present application relates to exocyclic amine-substituted coumarin derivatives and their uses as fluorescent labels. These compounds may be used as fluorescent labels for nucleotides in nucleic acid sequencing applications.

The present invention relates to dissymmetric azomethine direct dyes of formula (I) and the leuco forms thereof of formula (II), and also to the use thereof for dyeing keratin fibres, in particular human keratin fibres such as the hair:

##STR00001##

in which formula (I) or (II) R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6, n and n are as defined in the description.

The compounds of formula (I) or (II) according to the invention can give powerful, chromatic and sparingly selective colourings with good colour build-up, which are resistant to the various attacking factors to which keratin fibres may be subjected, such as inclement weather, light, washing and perspiration.

A compound excellent in chroma, light resistance and solubility. The compound has a structure represented by Formula (1).

##STR00001## wherein R.sub.1 and R.sub.2 each independently represent a linear or branched alkyl group having 1 to 12 carbon atoms, R.sub.3 represents a linear or branched alkyl group having 1 to 4 carbon atoms, an aryl group having a substituent, or an unsubstituted aryl group, and R.sub.4 represents an alkyl group having 1 to 4 carbon atoms; and R.sub.5 and R.sub.6 each independently represent a linear, branched or cyclic alkyl group having 1 to 8 carbon atoms, an alkyl group having a hydroxyl group at the terminal, an aryl group having a substituent, or an unsubstituted aryl group; and R.sub.5 and R.sub.6 may be combined to form a heterocycle.

The present invention relates to novel cationic azomethine direct dyes of formula (I) and the leuco forms thereof of formula (II), and also to the use thereof for dyeing keratin fibres, in particular human keratin fibres such as the hair: (I) (II) in which formula (I) or (II) X.sub.1, X.sub.2, R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6, n and n are as defined in the description. The compounds of formula (I) according to the invention can give powerful, chromatic and sparingly selective colourings with good colour build-up, which are resistant to the various attacking factors to which keratin fibres may be subjected, such as inclement weather, light, washing and perspiration.

##STR00001##

The present invention pertains generally to the field of chemical synthesis, and more particularly to methods for the chemical synthesis of a thiosulfonic acid of Formula (1) by a step of periodate mediated oxidative coupling of a thiosulfonic acid of Formula (2) with an aniline of Formula (3), as described herein. The present invention also relates to such methods which incorporate one or more additional (subsequent and/or preceding) steps, for example, to prepare compounds of Formula (5) from compounds of Formula (1); to prepare compounds of Formula (6) from compounds of Formula (5); and to prepare compounds of Formula (2) from compounds of Formula (4), as described herein.

##STR00001##