Eastman-kodak Company

Mark J Robbins

David G Lincoln

Michael Edgar Long

Samuel S Brody

David L Van Galio

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

A method of solvent fusing thermal images is disclosed herein an inert gas is bubbled through a liquid solvent to vaporize the solvent. The solvent temperature is controlled. The vaporized solvent fuses the image.

Solvent fusing of thermal printer dye image

Photographically useful compounds

Preparation of tetraazaindenes

Growing community of inventors

Rochester, NY, United States of America

Mark J Robbins