Ciba-geigy Ag

Aaron David Ezekiel

Rolf Steiger

Geoffrey E Ficken

Jean-Francois Reber

The present invention relates to light-sensitive photographic material with a light-sensitive heavy metal compound, e.g. a silver halide, and a spectral sensitizer. The spectral sensitizer is a compound in which the radicals of a sensitizing dyestuff are covalently bonded to amino, imino, hydroxyl, mercapto, carboxylic acid or carboxylic acid amide groups of a natural hydrophilic colloid, preferably gelatin. The invention also relates to new sensitizing dyes which are dinuclear cyanine dyes or merocyanine dyes which have attached either to a heterocyclic nucleus of the dye or to its methine chain a group which is reactive with a hydrophilic colloid.

Spectral sensitization of photographic material and new spectral

Spectral sensitization of photographic material with natural colloids

This invention relates to the new compound 2-aminonaphtho [1,2-d] selenazole of the formula ##STR1## Compound (I) is prepared by halogenating 1,2,3,4-tetrahydro-1-oxonaphthalene-3-sulphonate, reacting the halogenated compound with selenourea and then eliminating the sulphonic acid group. Compound (I) is useful as starting material for the preparation of 2-methylnaphtho [1,2-d] selenazole by hydrolyzing compound (I), acylating the hydrolysis product and ring closure.

Conversion of 2-aminonaphtho[1,2 d] selenazole to 2-methylnaphtho[1,2 d]

This invention relates to the new compound 2-aminonaphtho [1,2-d] selenazole of the formula ##SPC1## Compound (I) is prepared by halogenating 1,2,3,4-tetrahydro-1-oxonaphthalene-3-sulphonate, reacting the halogenated compound with selenourea and then eliminating the sulphonic acid group. Compound (I) is useful as starting material for the preparation of 2-methylnaphtho [1,2-d] selenazole by hydrolysing compound (I), acylating the hydrolysis product and ring closure.

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Ilford, United Kingdom

Aaron David Ezekiel