Eastman-kodak Company

David G Lincoln

Robert F Romanet

Susan M Fischer

Gary M Russo

Paul A Burns

Paul P Spara

Mark J Robbins

James L Edwards

Mbiya Kapiamba

Rajiv P Balasubramanian

Donald R Diehl

Daniel L Kapp

Gregg P Bryant

Disclosed is a photographic element comprising a light sensitive silver halide emulsion layer and, having associated with that layer, a 1H-pyrazo&lsqb;1,5-b&rsqb;-1,2,4-triazole dye forming coupler having a fully substituted carbon atom at the 6-position, a chloro group at the 7-position, and, at the 2-position, a propionic ester moiety.

Photographic material comprising a bicyclic pyrazolotriazole coupler with improved hue

Photographic element containing a red dye-forming pyrazolotriazole coupler

Photographic element containing azole couplers

Disclosed is a photographic element comprising a light-sensitive silver halide emulsion layer having associated therewith a bicyclic azole dye-forming coupler, having appended to a ring carbon at a non-coupling position thereof a substituent group represented by the formula:

Photographic element having improved dye stability, compound, and imaging process

The invention provides a photographic element comprising a silver halide emulsion layer having associated therewith a dye-forming coupler represented by formula II: wherein

Photographic element having improved magenta dye light stability and

The invention provides a photographic element comprising a silver halide emulsion layer having associated therewith a dye-forming coupler represented by formula II: ##STR1## wherein X is hydrogen or a coupling-off group;

A multi-step process for the preparation of tetraazaindenes provides new, intermediate compounds and methods for their formation. A first method or step (1) of the process comprises reacting Meldrum's acid (cyclic dimethylmethylene malonate) or a related compound with an orthoester to form a first intermediate. Another method or step (2) of the invention comprises reacting the first intermediate with a triazole to form a second intermediate. A third method or step (3) comprises reacting the second intermediate with a base to form a tetraazaindene salt from which the tetraazaindene can then be formed. Other methods of the invention comprise sequential combinations of the three new methods above described. For example, Meldrum's acid is reacted with triethylorthoacetate in the presence of pyridine and ethyl acetate to form a first intermediate represented by the structural formula ##STR1## The first intermediate is then reacted with 3-amino-5-methylthio-1,2,4-triazole to form a second intermediate represented by the structural formula ##STR2## Upon reaction with sodium carbonate, a tetraazaindene having the formula ##STR3## is produced. Other related compounds are formed when reactants related to those set forth above are employed. Tetraazaindenes are useful as photographic chemicals, for example, as image toners or stabilizers in photographic emulsions.

Method for preparing tetraazaindenes

Photographically useful compounds

Preparation of tetraazaindenes

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Webster, NY, United States of America

David G Lincoln