Pyridine-2,3,6-triones, process for their manufacture, their use as silver dye-bleach catalysts and photographic process.

摘要

New silver dye-bleach catalysts and the process for their manufacture are provided. These compounds have the general formula
<Chemistry id="chema01" num="0001"><Image id="ia01" he="29" wi="28" file="IMGA0001.TIF" imgContent="chem" imgFormat="TIFF" inline="no" /></Chemistry>wherein A is an electron-withdrawing group and R<Sub>1</Sub> and R<Sub>2</Sub> are hydrogen, optionally substituted alkyl or optionally substituted aryl.