Pyrazolidinone salts as developing agents

DETAILED DESCRIPTION We claim: 1.
A 1-phenyl-3-pyrazolidinone salt of the formula ##STR14## in which X.
sup.
.
crclbar.
is an organic anion, L represents the atoms necessary to complete an unsubstituted pyrrolidine, piperidine or morpholine ring, R.
sub.
1 is phenyl which is unsubstituted or substituted by alkyl, alkoxy, chloro, hydroxyl or amino, R.
sub.
2 and R.
sub.
3 are each hydrogen or lower alkyl which is unsubstituted or substituted by hydroxyl, alkoxy, aryloxy or amino, and R.
sub.
4 and R.
sub.
5 are each hydrogen, lower alkyl which is unsubstituted or substituted by hydroxyl, alkoxy, aryloxy or amino, or phenyl which is unsubstituted or substituted by alkyl, alkoxy, chloro, hydroxyl or amino.
2.
A 1-phenyl-3-pyrazolidinone salt of the formula ##STR15## 3.
A 1-phenyl-3-pyrazolidinone salt according to claim 1, wherein R.
sub.
2 and R.
sub.
3 are each hydrogen, methyl, hydroxymethyl or hydroxyethyl.
4.
A 1-phenyl-3-pyrazolidinone salt according to claim 1, wherein R.
sub.
4 and R.
sub.
5 are each hydrogen.
5.
A 1-phenyl-3-pyrazolidinone salt according to claim 1, wherein R.
sub.
1 is phenyl, p-tolyl or p-anisyl.




Description:
The present invention relates to novel developing agents.
It is well know that certain pyrazolidinone compounds are useful as components of photographic developing compositions, as described, for example, in chapter 11 of the book "The Theory of the Photographic Process", 4th edition, edited by T.
H.
James and published by Macmillan.
An example of such a compound is 1-phenylpyrazolidinone of the formula ##STR1## However, although widely used, developing agents of the pyrazolidinone class do suffer from certain disadvantages in their use.
One disadvantage is that they only dissolve slowly in water, and thus elevated temperatures or prolonged stirring are necessary in order to make up solutions containing compounds such as the compound of the formula (1).
A second disadvantage of such compounds is that they are susceptible to oxidation.
It is known that said compounds may be rendered resistant to oxydation by use of a suitable protecting group to replace the labile N--H group