Patent ID: 6890706

Claim:
A photographic processing solution comprising therein at least one compound of formula (I) wherein X is O or NH; n is 1 or 2, p is 0, M is hydrogen, an alkali metal, Ca or Mg, ammonium or a cation formed from an amine; each R 1 , independently, is an aminoacid residue from which a hydrogen atom on the amino group has been removed; each R 2 , independently, is hydrogen, C 1 -C 8 alkyl, C 1 -C 8 alkoxy, halogen, cyano, COOR, wherein R is hydrogen or C 1 -C 3 alkyl, CONH—R in which R has its previous significance, SO 2 NH—R in which R has its previous significance, NH—COR in which R has its previous significance, or SO 3 M, wherein M has its previous significance, or, if n is 1, R 2 can also be CO—R 3 in which R 3 is C 1 -C 3 alkyl or phenyl.