CA1134818A - Release compounds and photographic emulsions, elements and processes utilizing them - Google Patents

Abstract

Abstract of the Disclosure Photographic couplers which make available a photographically useful group by an intramolecular nucleo-philic displacement reaction can be used in photographic emulsions, elements and processes to provide a photographically useful group in a controlled manner.

Description

This invention relates to novel photographic compounds which make available photographically useful groups during photographic processing and to photographic emulsions, elements and processes utillzing such compounds. .
The art has recognized various ways in which a photographically useful group can be released from compounds in photographic elements and processes. For example, Whitmore et al U.S. Patent 3,148,062 and Barr et al U.S.
Patent 3,227,554 show the release of a development inhibitor or a dye from the coupling position of a photographic coupler upon reaction of the coupler with oxidized color developing agent. Bloom et al U.S. Patent 3,443,940 and Bloom U.S.
Patent 3,751,406 ~how a photographic coupler containing a dye in a non-coupling position. Reaction of the coupler wlth oxidized color developing agent followed by a ring closure reaction of the coupled developlng agent at the point of attachment of the dye leads to release of the dye from the coupler. Holtz U.S. Patent 3,705,801 shows photographic couplers which release from the coupling position thereof a bleach inhibitor upon reaction of the coupler with oxidized color developing agent. Fields et al U.S. Patent 3,980,479 shows compounds containing a nucleophilic group and a photo-graphically useful group attached to the compound through an electrophilic clea~age group. When sub~ected to alkallne conditions the nucleophilic group and the electrophilic cleavage group interact to release the photographically useful gr~up unless the compound has reacted wlth oxidized developing agent, in which event release is inhibited. Hinshaw et al U.S. Patent 4,199,354~ Chasman et al U.S. Patent 4,139,379 and Hinshaw et al U.S. Patent 4,13g,389 show other , B ~

~ ... , .. . ... .. . . .... , .. . Y,.. ... ... ... ... . .

113~B18 compounds from which a photographically useful group 16 released by a nucleophilic displacement reaction during photographic processing.
m us, as can be seen from these representative patents, the prior art has used several technlques to release imagewise a variety of photographically useful groups to be employed for various purposes in photographic elements and processes. A feature which these compounds and techniques have in common is that the photographlcally useful group is released directly from the compound in it6 useful form. Such direct release limits control over the timing and rate of relea6e of the photographically useful group, as well as over the rate and distance it may then travel through the element before reacting with another compound in the element. Some degree of control over these parameters may be obtained by suitably modifying one or more of:
(l) the moiety from which the photographically useful group is released, (2) the means of attachment of the photographically useful group to the moiety from which it is released and i 20 (3) the photographically useful group ltself. However, such modlficatlon may be inconsistent with the end use intended for the moiety or the photographically useful group and hence removes a degree of freedom ln designing a compound for a given purpose. For example, modifying a photographic coupler containing a development inhibitor BO as to modify the rate of release of the development inhibltor may affect not only rate of release but also may affect the hue of the dye formed B

. ... . , . . . ... ..... ... . .. i .

113~ 18 by the coupler and/or the reactivity or diffusivity of the development inhibitor.
Thus, there is a need for compounds that will release or otherwise make available photographically useful groups, but which will permit control over such parameters as time of release, rate of release, and rate of diffusion of the photographically useful group, without modifying the photographically useful group or the coupler moiety from which it is released in a way which would be inconsistent with the ultimate use for which each is intended.
I have found that this can be accomplished by means of a photographic coupler containing a timing group which is cleaved from the coupler as a result of reaction of the coupler with oxidized color developing agent and thereafter undergoes an intramolecular nucleophilic displacement reactlon to make available a photographically useful group.
One embodiment of my invention is the couplers as described above. Another embodiment of my invention is a process for forming photographic images by developing an exposed - 20 silver halide emulsion with a color developing agent in the presence of a coupler as described above. Other embodiments of my invention are silver halide emulsions and photographic elements containing couplers as described above.
Preferably, couplers of my invention contain a ;j timing group between a coupler moiety and a photographically useful group, so that reaction of the coupler with oxidized color developing agent cleaves the bond between the timing group and the coupler, and then an intramolecular nucleophilic displacement reaction cleaves the bond between the photo-graphically useful group and the timlng group. Thus, the sequential detachment of first the timing group from the ~3~

coupler moiety, followed by detachment of the photographically useful group from the timing group is a characteristic feature of compounds of this invention.

As used herein the terms "coupler' and "coupler compound" refer to the entire compound, including the coupler moiety, the timing group and the photographically useful group, while the term "coupler moiety" refers to that portion of the compound other than the timing group and the photographically useful group.

The particular timing group employed, including the linkage by which it is attached to the coupler moiety and the nature of the substituents on it, can be varied so as to control such parameters as rate and time of cleavage of the timing group from the coupler and of the photographically useful group from the timing group. Since these parameters can be controlled by modification of the timing group, they need not be emphasized in selecting the particular coupler moiety and the particular photographically useful group, thus providing greater freedom in selecting such moieties and groups for a particular end use.
If the photographically useful group is joined to the coupler moiety only through the timing group, then cleavage of the timing group from the coupler moiety releases the timing group and the photographically useful group as a unit. In this embodiment the particular timing group employed, including the nature of the substituents on it, can additionally control the rate and distance of diffusion of the unit formed by the timing group and the photographically useful group after this unit is released from the coupler moiety but before the photographically useful group is released from the timing group. If the photographically useful group is ~i~3~ 8 joined to the coupler moiety both directly and through the timin~ group, the particular timing group and the nature of the substituents on it can control the rates of cleavage of the timing group from the coupler and from the photo-graphically useful group, and, hence, can control the rate at which the photographically useful group is made available In this embodiment the direct linkage between the photographically useful group and the coupler moiety prevents diffusion of the photographically useful group.
In a preferred embodiment, my in~ention relates to a photographic coupler containing a timing group between a coupler moiety and a photographically useful group, the coupler moiety being joined to the timing group and the timing group being ~oined to the photographically useful group so that upon reaction of the coupler with oxidized color developing agent the timing group and the photographically useful group are released as a unit from the coupler moiety and thereafter the photographically useful group is released from the timing group by an intramolecular nucleophilic dis-placement reaction.
Photographic couplers of my invention, in one form, can be represented by the structure:
(I) COUP - TIME - PUG

where COUP is a coupler moiety, TIME is a timing group and PUG is a photographically useful group.
The coupler moiety can be any moiety which will react with oxidized color developing agent to release the -TIME-PUG group. It includes coupler moieties employed in conventional color-forming couplers which yield colored products on reaction with oxidized color developing agents as well as coupler moieties which yield colorless products on .
.

1~3~18 reaction with oxidized color developing agents. Both types of coupler moieties are well known to those skilled in the art and representative patents which describe them are referred to hereinafter.
The coupler moiety can be unballasted or ballasted with an oil-soluble or fat-tail group It can be monomeric, or it can form part of a dimeric, oligomeric or polymeric coupler, in which case more than one -TIME-PUG group can be contained in the coupler, or it can form part of a bis compound in which the TIME or PUG group forms part of the link between two coupler moieties.
It will be appreciated that, depending upon the particular coupler moiety, the particular color developing agent and the type of processing, the reaction product of the coupler moiety and oxidized color developing agent can be: (1) colored and nondiffusible in which case it will remain in the location where it is formed; (2) colored and diffusible, in which case it may be removed during processing from the location where it i~ formed or allowed to migrate to a different location; or (3) colorless and diffusible or non-diffusible, in which case it will not contribute to image density. In cases (2) and (3) the reaction product may be initially colored and/or non-diffusible but converted to colorless and/or diffusible products during the course of processing.
The -TIME-PUG group is ~oined to the coupler moiety at any of the positions from which groups released 113~818 from couplers by reaction with oxidized color developing agent can be attached. Preferably, the -TIM~-PUG group can be attached to the coupling position of the coupler moiety so that upon reaction of the coupler wlth oxidized color developing agent the -TIME-PUG group will be displaced. However, the -TIME-PUG group can be in a non-coupling position of the coupler moiety, e.g.
as in Bloom U.S. Patent 3,443,940 referred to above, from which position it will be displaced as a result of reaction of the coupler with oxidized color developing agent. In the case where the -TIME-PUG group is in a non-coupling position of the coupler moiety, other groups can be in the coupling position, including conventional coupling-off groups or the same or a different photographically useful group from that contained in the -TIME-PUG group. Alternatively, the coupler moiety can have a -TIME-PUG group in each o~ the coupling position and a non-coupling position. Accordingly, couplers of this invention can release more than one mole of photo-graphically useful group per mole of coupler. The photo-~0 graphicælly useful groupscan be the same or different and can be released at the same or different times and rates.
The timing group can be any organic group which will serve to connect COUP to PUG and which, after cleavage of the unit -TIME-PUG from COUP, will cleave from PUG by an intramolecular nucleophilic displacement reaction. The term "intramolecular nucleophilic displacement reaction" is understood to refer to a reaction in which a nucleophilic center of a compound reacts directly, or indirectly through an intervening molecule, at another site on the compound, which is an electrophilic center, to effect displacement 113~18 of a group or atom attached to the electrophilic center.
Gener~lly, such compounds have a nucleophilic group and an electrophilic group spatially related by the configuration of the molecule to promote reactive proximity. Preferably the nucleophilic group and the electrophilic group are located in the compound so that a cyclic organic ring, or a transient cyclic organic rin~, can be easily formed by an intramolecular reaction involving the nucleophilic center and the electrophilic center.
A nucleophilic group is understood to be a grouping of atoms one of whicn is electron rich. This atom is referred to as the nucleophilic center. An electrophilic group is understood to be a grouping of atoms one of which is electron deficient. This atom is referred to as the electrophilic center.
Thus, ln photographic couplers of this lnvention, the timing group contains a nucleophilic group and an electrophilic group which are spatially related with respect to one another so that upon release of -TIME-PUG from the coupler moiety the nucleophilic center and the electrophilic center will react to effect displacement of the photographically useful group from the timing group. In order to assure that the photographically useful group is not released prior to release of -TIME-PUG from the coupler moiety, the nucleophilic center should be prevented from reacting with the electrophilic center until such release and the electrophilic center should be resistant to external attack, e.g. hydrolysis. Premature reaction can be prevented by attaching the coupler moiety to the timing group at the nucleophllic center, so that cleavage of -TIME-PUG ~rom the coupler moiety unblocks the nucleophilic center and permits lt to react with the electrophilic center, or by positioning the nucleophilic group and the electro-_g_ Xl . .,, , . , . , ~,, .

t.

113(~818 philic group so that they are prevented from coming into reactive proximity until release. Similarly, the photo-graphically useful group will be attached at a position on the timing group from which it will be displaced upon reaction of the nucleophilic center and the electrophilic center.
Release of the photographically useful group can lnvol.ve a single reaction once the timing group is cleaved from the coupler moiety or it can involve sequential reactions.-For example, two sequential intramolecular nucleophilic dis-placement reactions may be required within the timing group to effect release of the photographically useful group. As another example the intramolecular nucleophilic displacement reaction may release a second coupler which contains another timing group to which the photographically useful group is joined and fror, which it is released after the ~econd coupler reacts with oxidized color developing agents.
The timin~ group can contain moieties and substituents which will permit control of one or more of the rate of reaction of COUP with oxidized color developing agent, the rate of diffusion of TIME-PUG once it is released from COUP and the rate of release of PUG by the intramolecular nucleophilic displacement reaction. The timing group can contain additional substituents, such as additional photo-graphically useful groups, or precursors thereof, which will remain attached to the timing group.
The photographically useful group can be any group that is desirably made available in a photographic element in an imagewise fashion. The photographically useful group can be a photographic dye or dye precursor, or a 3o photographic reagent ~uch as a development inhibitor, a t development accelerator, a bleach inhibitor, a bleach accelerator, a coupler (e.g. a competing coupler, a color-forming coupler~ a DIR coupler, etc.), a developlng agent X

113~318 (e.g. a competing developing agent), a silver halide solvent, a silver complexing agent, a fixing agent, a toner, a hardener, a tanning aga~, a fogging agent, an antifoggant, a chemical or spectral sensitizer, a desensitizer, etc.
m e photographically useful group can be present in the coupler as a preformed species or it can be present in a blocke~ form or as a precursor. For example, a preformed development inhibitor may be attached to the ti~ng group or the development inhibiting function may be blocked by being the point of attachment to the timing group.
As another example, a preformed dye may be attached to the timing group, a dye which is blocked so as to shift its 6pectral absorption may be attached to the timing group or a leuco dye may be attached to the timing group.
Preferred compounds according to thi~ invention lnclude a photographic coupler containing a coupler moiety, a photographically useful group, and a timing group ~oining the coupler moiety and the photographically useful group, the timing group comprising a ~cleophilic group attached to the coupler moiety at a position from which it is displaced as a result of reaction of the coupler moiety wlth oxidized color developing agent, an electrophilic group attached to the photographically useful group, and a linking group 6patially relating the nucleophilic group and the electro-philic group to undergo, after cleavage of the timing group and the photographically useful group from the coupler moi0ty, an intramolecular nucleophilic displacement reaction which cleaves the photographically useful group from the timing group. Preferably, the nucleophilic group and the electrophilic group are spatially related within the timing group 60 that the intramolecular nucleophilic X

il3~8il3 dlsplacement reaction involves the formation of a three-to seven-membered rin~, preferably a five- to seven-membered rin~.
A preferred class of photographic coupler compoundc of this invention can be represented by the structure:

(1' ) I

I~lu X-E

where:
CvU~ is a coupler moiety, as described above, PU5 is a photo5raphically useful group, as described above, Nu is a nucleophilic group attached to a pocition on COUP from ~hich it will be displaced upon reaction of C~UP with oY.idized color developln5 ~ agent;
; ~ is an electrophilic ~roup, and X is a lin~ing group for spatially relating Nu and E, upon release of Nu from COUP, to undergo an intramolecular nucleophilic displacemer.t reaction with the for~ation of a three-to seven-membered ring and thereby release PUG~ ~' Representative Nu groups contain electron rich oxygen, sulfur and nitrogen atoms. Representative E groups contain electron deficient carbonyl, thiocarbonyl, phosphinyl and thiophosphinyl moieties.
In the followin~ listings of representative Nu and E groups, the groups are oriented so that the lefthand bond of Nu is ~oined to COUP and the righthand bond of Nu is ~oined .
~;
.. , . . . - -. .

1139~818 to X, while the lefthand bond of E i6 ~oined to X and the rlghthand bond of E is ~oined to PUG.
Representative Nu groups lnclude: -0-(CR2)n~, 0 0 o R 0 0 ,0, -S-(CR2)n-, -S-, -S-, -0-S-, -N-S-, -0-C-(CR2)n-, -0-C-0-, O o ., " ~ Il ", 0-C-(CR ) -, -0-C-0-, -N-C-(CR2)n~, -0-C-N-, -0-N- a~d ~0-P-(CR2)n-, R

where each R is independently hydrogen, alkyl of 1 to 20 carbon atoms such as methyl, ethyl, propyl, hexyl, decyl pentadecyl, octadecyl and the like, or aryl of 6 to 20 carbon atoms such as phenyl, naphthyl, benzyl, tolyl, t-butylphenyl, carboxyphenyl and the like, and n is an integer from 0 to 4 such that the ring formed by Nu, X and E upon nucleophilic attack of Nu upon the electrophilic center in E
contains 3 to 7 ring atoms. Preferably R is hydrogen or lower alkyl of 1 to 4 carbon atoms.
,0, ; Representative E groups include: -(CR2)n-C-, ", , ~, ' ~(CR2)n~C-~ ~S(CR2)n~c-~ ~(CR2)n~N~C-, ~(CR2)n~N~C~~

, " " " "
~S(CR2)n-N-C-, -(CR2)n-C-, -O(CR2)n-C-, -S(CR2)n-C-, ~(CR2) ~ -- ~ ................... .. ..
O(CR ) -N-C-,-S(CR2)n-N-C-~ ~(CR2)n N, "2 n , , R RR R
where R and n are defined above.

.

~13~818 The linking group represented by X can be an acyclic group such as alkylene (e.g. methylene, ethylene, propylene, etc.) but preferably is a cyclic group such as an aromatic group (e.g. phenylene, naphthylene, etc.) or a heterocycllc group (e.g. furan, thiophene, pyridine, qulnoline, benzoxazine, etc.). The groups Nu and E are attached to X to provide, upon release of Nu from COUP, favorable spatial relationship for nucleophilic attack of the nucleophilic center in Nu on the electrophilic center in E. When X is an aromatic or heterocyclic group, Nu and ~ can be attached to the same or adjacent rings. Aromatic groups in which Nu and E are attached to ad~acent ring positions are pzrticularly preferred X groups.
Particularly preferred couplers of structure II
above can be represented by the structure:

(III) Nu ,t ~1 ; where:
COUP is a coupler moiety;
Nu is a nucleophilic group attached to the coupling position of COUP, selected from the group consisting of -0-, -0-CR2-~ -0-C-, -N-C-,-S, -S-CR2-, and -N-,S,-O
where e~ch R i6 independently hydrogen or alkyl of 1 to 20 carbon atoms, preferably lower alkyl of 1 to 4 carbon atoms, .. . .. . . . . . ~ . - - - - i , .

~3~818 Z represents the atoms necessary to complete a mono- or bicyclic aromatic or heterocyclic ring system -containing 5 to 10 ring atoms, preferably containing ring atomF selected from carbon, oxygen, nitrogen and sulfur;
E is an electrophilic group selected from the I
group consisting of -(CR2)n-C-, -(CR2)n-N-C-, S R S
.. , ..
~(CR2)n-C- and -(CR2)n-N-C-;
where each R is inGependently hydrogen or alkyl of 1 to 20 carbon atom~, preferably lower alkyl of 1 to 4 carbon atoms and n is an integer of 0 to 4 such that the ring formed upon reaction of the nucleophilic center in Nu with the electro-philic center in E contains 5- to 7-members; and PVG is a photographically useful group; PUG being attached to a position in E from which it will be displaced upon nucleophilic attack of Nu at the electrophilic center in E.
In the above structure III the nucleus completed by Z can be unsubstituted or substituted. The substituents can be those which will modify the rate of reaction, diffusion, or displacement, such as halogen (e.g. fluoro, chloro, bromo, iodo), nitro, alkyl of 1 to 20 carbon atoms, acyl (e.g. carboxy, carboxyalkyl, alkoxycarbonyl, alkylcarbonamido, sulfoalkyl, alkylsulfonamido, alkylsulfonyl, etc.), ballast groups and the like, or they can be substituents which are separately useful in the photographic element such as a stabilizer, an ~ antifoggant, a dye (e.g.~ a filter dye, a solubilized masking ; dye) and the like. For example, solubilizing groups will increase the rate of diffusion; ballast groups will decrease the rate of diffusion; electron withdrawing groups will -~5-X

.. . ........ . .......
., 113~818 decrease the rate of displacement of the photographically useful group; and photographically useful groups which remain attached to Z can serve functions such as stabilization, masking and the like.
There follows a listing of patents and publications which describe representative COUP and PUG groups useful ln the in~ention. Also listed are structures of preferred COUP, TIM~ and PUG groups. In these structures the unsatisfied bonds in each of COUP and PUG show the point of attachment to TIM~, the lC vertical unsatisfied bond in TIME shows the point of attachment of COUP and the horizontal unsatisfied bond in TIME shows the point of attachment to PUG.
I COUP's A. Couplers which form cyan dyes upon reaction with oxidized color developing agents are described in such representative patents and publications as: U.S. Patents

2,772,162, 2,895,ô26, 3,002,836, 3,034,892, 2,474,293, 2,423,730, 2,367,531, 3,041,236 and "Farbkuppler-eine Literaturubersicht," published in Agfa Mitteilungen, Band II, pp. 156-175 (1961).
Preferably such couplers are phenols and naphthols which form cyan dyes on reaction with oxidized color developing agent and have the -TIME-PUG group attached to -~ the coupling position, i.e. the carbon atom in the 4-position.
Structures of preferred such coupler moieties are:

IA-l OH
R2 ~ NHCOR

OlH , R2 ~ CNHR

113~81i3 ~ NHCOR
RlCONH--~J

OH
~ CONHR

where Rl represents a ballast group, and R2 represents one or more halogen (e.g. chloro, fluoro), lower alkyl (e.g.
methyl, ethyl, butyl) or lower alkoxy (e.g. methoxy, ethoxy, butoxy) groups.

B. Couplers which form magenta dyes upon reaction with oxidized color developing agent are described ln ~uch representative patents and publications as: U.S. Patents 2,600,788, 2,369,489, 2,343,703, 2,311,082, 3,152,896, 3,519,429,

3,062,653, 2,908,573 and "Farbkuppler-eine Literaturubersicht,"
published in Agfa Mitteilungen, Band II, pp. 126-156 (1961).
; Preferably such couplers are 5-pyrazolones which ~; form magenta dyes upon reaction with oxidized color developing agent and have the -TIME-PUG group attached to the coupling position, 1.e. the carbon atom in the 4-position. Structures of preferred such coupler moieties are:

IB-l R2 -N - N
O~JLNH-R

IB-2 R2 -N N o 1 11 "
HC R

-17_ '~' ; . . , ' . :
, : ~

~13'~3i8 where R1 is as defined above and R2 is as defined above or is phenyl or substituted phenyl (e.g. 2,4,6-trihalophenyl).

C. Couplers which form yellow dyes upon reaction with oxidized and color developing agent are described in such representative patents and publications as: U.S.
Patents 2,875,057, 2,407,210, 3,265,506, 2,298,4432 3,048,194, 3,447,928 and "Farbkuppler-eine Literaturubersicht,"
published in Agfa Mitteilungen, Band II, pp. 112-126 (1961).
Preferably such yellow-dye forming couplers are acylacetamides, such as benzoylacetanilides and pivalyl-acetanilides, and have the -TIME-PUG group attached to the coupling position, i.e. the active methylene carbon atom.

Structures of preferred such coupler moieties are:

IC-l R2 O O
R ~ -CH-CNH ~ ~ R

IC-2 (cH3)3c-c-cH-cNH ~ 1 where Rl is as defined above and R2 is hydrogen or one or more halogen, lower alkyl (e.g. methyl, ethyl) or ballast (e.g. alkoxy of 16 to 20 carbon atoms) groups.

D. Couplers which form colorless products upon reaction with oxidized color developing agent are described - in such representative patents as: U.K. Patent 861,138;
U.S. Patents 3,632,345, 3,928,041, 3,958,993 and 3,961,959.
Preferably such couplers are cyclic carbonyl containing compounds which form colorless products on reaction with . ~' ~1 3~B1 8 oxidized color developing agent and have the -TIME-PUG
group attached to the carbon atom in the ~-pos~tion with respect to the carbonyl group.
Structures of preferred such coupler moieties are:

ID-l O

R ~
(CH2)n n = 1, 2 ID-2 o Rl ~ H2)n n = 1, 2 ~XR1 ID-4 o o where Rl ls as defined above.
- ., E. Couplers which ~orm black dyes upon reactlon with oxidized color developing agent are described in such representative patents and patent application6 as U.S.
Patents 1,939,231, 2,181,944, 2,333,106, u.s. Patent

4,126,461, German OLS 2,644,194 publi6hed April 21, 1977 and German 01S 2,650,764 published May 18, 1977.

B

. ~

113~i318 Preferably such couplers are resorcinols or m-aminophenols which form black or neutral products on reaction with oxidized color developing agent and have the -TIME-~UG group para to a hydroxy group.
Structures of preferred such coupler moieties are:
OH

IE-l ~ - NHCOR

OH

OH

~j~ COOR
~--~OH

~ \R2 where Rl is alkyl of 3 to 20 carbon atoms, phenyl or phenyl substituted with hydroxy, halo, amino, alkyl of 1 to 20 carbon atoms or alkoxy of 1 to 20 carbon atoms; each R2 is independently hydrogen, halogen, alkyl of 1 to 20 carbon atoms, alkenyl of 1 to 20 carbon atoms, or aryl of 6 to 20 carbon atoms; and R3 is one or more halogen, alkyl of 1 to 20 carbon atoms, alkoxy of 1 to 20 carbon atoms or other monovalent organic groups.

II TIME's A. Acyclic TIME groups:

IIA-l Zl O
1~
(CH2)n- N -C - n = 1-4 .

113~818 . .
where Zl is O , C=O, or S; and R3 is hydrogen, alkyl of 1 to 20 carbon atoms, preferably lower alkyl of 1 to 4 carbon atoms, or aryl of 6 to 20 carbon atoms.
B Aromatic ~IME groups:

IIB~

~ (CH2 )n-N-C-Xl 3 X~
. . .
where n is O or 1, ~ is 0, 0 , o , S, CH2 C=O
, NH NH
O=S=O, or C=O, R3 is as defined above, and Xlis hydrogen, cyano, fluoro, chloro, bromo, iodo, nitro, alkyl of 1 to 20 carbon atoms, a dye, -OR4, -COOR4,-CONHR4, -NHCOR4,-NHS02R4, -S02NHR4 or S02R4 where ~4 i8 hydrogen or alkyl of 1 to 20 carbon atomr preferably alkyl of 1 to 4 carbon ~tom~.

`~
- . . . . . .. .

.113~Bi8 C. Heterocyclic TIME groups:

IIC-l I

IIC-2 ~ (CH2)n-N-C~

where n is 0 or 1, Z2~ Xl and R3 are as defined above.
D, Bis TIM~ groups:
_ _ IID-l Z
12 R3,0~

Y [~ (CH2)n~N~C~ ~, Xl ~ . ~
where Y is a linking group, such as C=0, 0=S=0 or -N~S02CH2S02NH-,n is O or 1 and Xl, Z2 and R3 are as defined above.

, ! , ~ . . ~ ~

113g~18 IID-2 Z2 R3,0, 0 R3 ~ (CH2~n-N
~C-N-(CH2)n ~

where n is 0 or 1 and Z2~ and R3 are as defined above.

III PUG's A. PUG's which form development inhibitors upon release from TIME are described in such representative patents as U.S. Patents 3,227,554; 3,384,657; 3,615,506;
3,617,291, 3,733,201 and U.K. Patent 1,450,479. Preferred development inhibitors are iodide and heterocyclic compounds ~uch as mercaptotetrazoles, selenotetrazoles, mercaptobenzo-10thiazoles, selenobenzothiazoles, mercaptobenzoxazoles, selenobenzoxazoles,mercaPtobenZimidazoles, selenobenzimidazoles, benzotriazoles and benzodiazoles. Structures of preferred development inhibitor moieties are:
. R5 ~N - N
IIIA-l . -S ~ \ ¦¦
N~ N
, , . X ' - ~ . - . , .

1~3g~1~

IIIA-5 -N~N ~ R6 IIIA-6 - N ~N

where R5 is hydrogen, lower alkyl of 1 to 4 carbon atoms (e.g. methyl, ethyl, butyl) or phenyl and R6 is hydrogen or one or more halogen (e.g. chloro, fluoro, bromo), lower alkyl of 1 to 4 carbon atoms or nitro groups.
B. PUG's which are, or form, dyes upon release ~rom -TIME-:
Suitable dyes and dye precursors include azo, azomethine, azopyrazolone, indoaniline, indophenol, anthra-quinone3 triarylmethane, alizarin, nitro, quinoline, indigoid and phthalocyanine dyes or precursors of such dyes such as leuco dyes, tetrazollum salts or shifted dyes. These dyes can be metal complexed or metal complexable. Representative patents describing such dyes are U.S. Patents 3,ô80,658;
3,931,144; 3,932,380; 3,932,381 and 3,942,987. Preferred dyes and dye precursors are azo, azomethine and indoaniline dyes and dye precursors. Structures of ~ome preferred dyes and dye precursors are:

X

.

1.13~18 ~02C~3 IIIB~l --o~N-N~3No2 ~2 ~S2NH2 I I IB -2 ~3N ~o OC71115-OC02CH2C~5 Cl NHCO (CH2 ) 4 ~b ~C02CH2C6H5 ~N-N-R" ' ;~

, 113~8113 R" R" ' (C~2)21S02ClffH33 C~3 C~3 -C1 . ~ 2N~
C1~29-~
~;02N~C~13-n 3902N~
02~ C6~1~n ~02NHC~l~n 3602N~9 ~02NE~C6~113 -n ' --Cl ~802NI~
1~2~-~

C. PUG's which are couplers:
Couplers released from -TI~E- can be non-diffusible color formln~ coupler~, non-color ~orming couplers or diffus~le competing couplers. Representative patents and publications and preferred structures for the first two categories are shown above in IA through IE. Representative patents and publications describing competing couplers are: "On the Chemistry of White Couplers," by W. Puschel, Agfa-Gevaert AG Mitteilungen ans der Forschungs-laboratorium der Agfa-Gevaert AG, Springer Verlag, 1954, pp.352-367, U.S. Paten~ 2,998,314, 2,808,329, 2,689,793, 2,742,832; German Patent 1,168,769 and British Patent 907,274. Structures of preferred competing couplers are:

~i 1~

.

1.13 ~18 IIIC-l ~ R8 ,~

where R7 is hydrogen or alkylcarbonyl (e.g. acetyl) and R8 is hydrogen or a solubilizing group (e.g. sulfo, carboxy, etc.).

IIIC-2 ~
_o~ R8 where R8 is as defined above and Rg is halogen, aryloxy, aryl-thio, or a development inhibitor, such as a mercaptotetrazole (e.g. phenylmercaptetrazole or ethyl mercaptotetrazole.) D PUG's which form developing agents:
; Developing agents released from -TIME- can be color developing agents, black-and-white developing agents or cross-oxidizing developing agents. They include aminophenols, phenylene diamines, hydroquinones and pyrazolidones.
Representative patents are: U.S. Patents 2,193,015, 2,108,243, 2,592,364, 3,~55,950, 3,658,525, 2,751,297, 2,289,367, 2,772,282, ~: 2,743,279, 2,753,265 and 2,304,953.
Structures of preferred developing agents are:

IIID-l ~ Rll -O~NHRlo where Rlois hydrogen or lower alkyl of 1 to 4 carbon atoms and Rll is hydrogen or one or more halogen te.g. chloro, bromo) or lower alkyl (e.g. methyl, ethyl, butyl) groups.

~13'~818 --O--~OH

where Rll is as defined above.

R12 o :

,NÇ ~ .

[~ Rlo RI2t~ -~ .

:
~: IIID-5 -NH ~ \R12 .

113~318 where Rlo is as defined above and R12 is hydrogen, lower alkyl of 1 to 4 carbon atoms (e.g. methyl, ethyl) lower hydroxy-alkyl of 1 to 4 carbon atoms (e.g. hydrox~methyl, hydroxyethyl) or lower sulfoalkyl E. PUGIs which are bleach inhibitors:
Representative patents are U.S. Patents 3,705,801, 3,715~208 and German OLS 2,405,279 published Au~ust 8, 1974.
Structures of preferred bleach inhibitors are:

IIIE-l -S ~
_ N

~ '' N _ N o IIIE-2 -S~ "
~ S--C--NHC-R13 i lIIE-3 -S ~ N ~ C-R13 H
IIIE-4 -S ~ 3 ; N
- where R13 ls an alkyl group of 6 to 20 carbon atoms.
. Typically, the couplers of this invention are prepared by attaching to the appropriate coupler moiety, or a derlvative of the coupler moiety, the linking group through the nucleophilic group. The linking group will have, in the appropriate spatial relationship to the nucleophilic group, a derivative of the electrophilic group, or another sultable functional group, which will form the electrophillc B

. . .

~3~8~8 group when the photographically useful group is attached.
This is then reacted with an appropriate derivat~ve of the photographically useful group to form the desired coupler.
Known reactlons are employed to perform these steps. The working examples sho~ the way ln whlch these steps can be performed using 6pecific reactants and reactions.
The photographic couplers of this invention can be incorporated in photographic elements or in photographic processin~ solutions, such as developer solutions, so that upon development of an exposed photographic element they will be in reactive association with oxidized color developing agent.
Coupler compounds incorporated in photographic processing solutions should be of such molecular size and configuration that they will diffuse through photographic layers with the processing solution. When incorporated in a photographic element, as a general rule, the coupler compounds should be non-diffusible, i.e. they should be of such molecular size and configuration that they will not signlficantly diffuse or wander from the layer in which they are coated.
Photographic elements of this invention can be processed by conventional techniques in which color forming couplers and color developing agents are incorporated in separate processing solutions or compositions or in the element.
The elements can ~e processed by redox amplification techniques ln which developed or latent lmage silver acts as a catalyst for oxidation of the color developing agent by an oxidizing agent such as a transition metal complex (e g. cobalt hexam~ne or a peroxide (e.g. hydrogen peroxide). Amplification processing is described, for example, in ~.S Patents 3,674,490;
3,822,129; 3,834,907; 3,841,873; 3,847,619; 3,862,842;
3,902,905 and 3,923,511.

. .

1~3~

Photographic elements ln which the photograph~c couplers of this invention are incorporated can be a simple element comprising a support and a single silver halide emulsion layer or they can be multilayer, multicolor elements.
The coupler compounds of this invention can be incorporated ln the silver halide emulsion layer or in another layer, such as an ad~acent layer, where they will come into reactive association with oxidized color developing agent which has developed ~ilver halide in the emulsion layer. The silver halide emulsion layer can contain, or have associated with it, other photo-graphic coupler compounds, such as color forming couplers, colored masking couplers, etc. These other photographic coupler compounds can form dyes of the same or different color and hue as the photographic coupler compounds of this invention.
Additionally, the silver halide emulsion layer can contain addenda conventionally contained ln such layers.
A typical multilayer, multlcolor photographic element according to this inventlon can comprise a ~upport having thereon a red-sensitive silver halide emulslon unlt having associated therewith a cyan dye lmage providing material, a green-sensitive silver halide emulsion unit having associated therewith a magenta dye image providing material and a blue-sensitive silver halide emulsion unit havlng associated ; therewith a yellow dye image-providing material, at least one of the silver halide emulsion units having associated therewlth a photographic coupler of the invention. Each silver halide emulsion unit can be composed of one or more layers and the various units and layers can be arranged in different locations with respect to one another. Typical arrangements are described in U.S. Patents 3,227,554; 3,620,747; 3,843,369; and 4,184,876 and U.K. Patent 923,045. The coupler compounds of this invention ~ ;B

113~8 can be incorporated in or associated with one or more layer~ or units of the element. If -TIME-PUG or PUG is a diffusible moiety, the layer(s~ and unit(s~ affected by PUG
can be controlled by incorporating in appropriate locations in the element scavenger layer(s) which will confine the action of PUG to the desired layer(s) or unit(s).
The light sensitive silver halide emulsions can include coarse, regular or fine grain silver halide crystals or ~ixtures thereof and can be comprised of such silver halides as silver chloride, silver bromide, silver bromoiodide, silver chlorobromide, silver chloroiodide, silver chlorobromoiodide and mixtures thereof. The emulsions can be negative working or direct-positive emulsions. They can form latent images predominantly on the surface of the silver halide grains or predominantly on the interior of the sllver halide grains. They can be chemlcally and spectrally sensitlzed.
The emulsions typically will be gelatin emulslons although other hydrophilic colloids can be used in accordance with usual practice.
The support can be any suitable support used with photographic elements. Typical supports include cellulose nitrate film, cellulose acetate film, polyvinylacetal film, polyethylene terephthalate film, polycarbonate film and related films or resinous materials as well as glass, paper, metal and the like. Typically, a flexible support is employed, such as a polymeric film or paper support. Paper supports can be acetylated or coated with baryta and/or an a-olefin polymer, particularly a polymer of an a-olefin containing 2 to 10 carbon atoms such as polyethylene, poly-propylene, ethylene-butene copolymers and the like.

B
...._ .

113~8 Further details regarding silver halide emulsi4ns ~nd el~ments, ~nd addenda incorporated therein can be found in Research Disclosure, December 1971, Item 9232, Paragraphs I
through XVIII. Research Disclosure is p~blished by Industrial .
Opportunities Ltd., Homewell, Havant, Hampshire, PO9 lEF~
United Kingdom.
The novel photographic couplers of my invention can be used in photographic elements in the 6ame ways as photo-graphic couplers which release photographically userul groups have previously been used in photographic elements. However, because of the improved ability to control the release of the photographically useful group, my couplers permit enhanced effects or more selective e~fects than heretofore pos~ible.
In addition, my couplers can be employed in applications where conventional couplers have previously been employed and a separate component was employed to provlde a photographically useful group.
Depending upon the nature of the particular photo-graphically useful group, my couplers can be incorporated in 20 a photographic element for different purposes and in different locations and these elements can contain ~arious other component~.
Reference will be made to exemplary ways in which preferred photographically useful groups can be lncorporated.
When the photographically useful group released ; from the coupler is a development inhibitor, it can be employed in a photographic element a6 described, for example, in U.S. Patents 3,227,554; 3,620,747; 3,703,375 and U.S.
Patent 4,184,876.
Other patents and application~ describing ways in which coupler~ which release development inhibltor~ can be employed are U.K. Patent 1,460,991; U.S. Patent 3,892,572 and German OIS 2,516,982 published December 11, 1975. Couplers of this .~
.. . ..

~ 13~
ihich release a development inhibitor can be contained in, or in reactive association with, one or more of the silver halide emulsion units in a color photographic element. If the silver halide emulsion unit is composed of more than one layer, one or more of such layers ca~ contain the coupler of this invention. The layers can contain other photographic couplers conventionally used in the art. The couplers of this invention can form dyes of the same color as the color forming coupler(s) in the layer or unit, it can form a dye of a different color, or it can result in a colorless or neutral reaction product. The range of operation of the ~-development inhibitor between layers when released from the coupler of this invention can be controlled by the use of scavenger layers, such as a layer of a fine grain silver halide emulsion. Scavenger layers can be in various locations in an element containing couplers of this invention.
They can be located between layers, between the layers and the support, or over all of the layers.
Couplers of this invention which release development inhibitors can enhance the effects heretofore obtained with DIR couplers since they can release a development inhibitor at a distance from the point at which oxidized color developing agent reacted with the coupler, in which case they can provide enhanced interlayer interimage effects and enhanced intralayer chemical adjacency effects. Thus, the couplers of this invention provide a degree of control over the effects obtainable from DIR couplers which heretofore could not be ; attained.
Photographic couplers of this inventlon which release bleach ~nhibitors can be employed in the ways described in U.S. Patent 3,705~801, to inhibit the bleaching of silver in selected areas of a photographic element.

B

113g~18 Photographic couplers of this invention which release a dye or dye precursor can be used in processes where the dye is allowed to diffuse to an integral or separate receiving layer to form a desired image as described for example ln U.S. Patents 3,227,551; 3,443,940 and 3,751,406.
Alternatively, the dye can be retained in the location where it is released to augment the density of the dye formed from the coupler from which it is released or to modify or correct the hue of that dye or another dye. In another embodiment, the dye can be completely removed from the element and the dye which was not released from the coupler can be retained in the element as a color correcting mask.
Couplers of this invention in which the photo-graphically useful group is a coupler can be employed to release another coupler. If the released coupler is a dye-forming coupler it can react with oxidized developlng agent in the same or an ad~acent layer to form a dye of the sa~e or a different color or hue as that obtained from the primary coupler. If the released coupler is a competing coupler it 20 can react with oxidized color developing agent in the same or an ad~acent layer to reduce dye density. l Photographic couplers of this invention in which the photographically useful group is a developing agent can be used to release a developing agent which will compete with the color forming developing agent, and thus reduce dye density. Alternatively, they can provide, in an imagewise manner, a developing agent which because of such considerations as activity would not desira~ly be introduced into the element in a uni~orm fashion.
3~ The following examples further illustrate this invention.

.

~ ) 113~318 o .

o~O

Q ~ æ
¢

~ C
~ ~ I Z

C ~ H ;~

. ~
e~

~d_ ' ~ ' ' . .
. . .. . .

~ ) 113~318 - ~ ' .~ . .

N ~

~ s~L

O ~

o~o~8 ~N

~ /
-- ~ C /
~a X x ~~ , o~o~8 ; e d ' : ~ . .
.. ,~ .
.
~ .

-37- .
'X

1~3~15 1i3 Preparation of Compound II
In a l-liter ~tainless steel Parr hydro~enation vessel was placed 100 g (0.14 mol) o~ compound I, 1.0 g of 10/~c Pd/C
catalyst, and 500 ml ethyl acetate. The mixture was reduced under 40 p.s.i. of hydrogen at ambient temperature. After the theoretlcal uptake of hydroge~, the catalyst was removed and the solvent evaporated in vacuo. The crude product was recrystallized from acetonitrile to give 67 g (70%) of white crystalline solid, m.p. 174-175C.
Preparation of Compound III
A 500 ml 3-neck round bottom flask was charged with 50 g (0.073 mol) of compound II, 14.5 g (0.15 mol) of succinimide, 11.9 ml (0.15 mol) of formalin, and 250 ml ethanol. The reaction mixture was heated on a steam bath for 30 hours. After cooling, the mixture wa6 poured lnto 1200 ml water and 60 ml ethyl acetate, with thorough stirring. The organic phase was separated, dried over magnesium sulfate, and the solvent evaporated in vacuo. The crude residue was taken up in a minimum amount of benzene and chromatographically separated with a silica-gel column using benzene and ethyl acetate as eluants. The fractions containing the product were combined and the solvent evaporated in vacuo. The solid residue was recrystallized from h~xane giving 30.4 g (53%) of pure colorless - crystalline product, m.p. 102-105C.
Preparation of Compound IV
To a stirre~ solution of 30.4 g (0.04 mol) of compound III ln 250 ml dimethyl ulfoxide was added portionwise 1.8 g (0.05 mol) of sodium borohydride, maintaining the temperature below 40C. After stirring for an additional 30 minutes, the .~

mixture was poured into water and extracted with ethyl acetate. The organic extracts were combined, washed with brine, dried over magnesium sulfate and the solvent evaporated in vacuo. The residue was taken up in a minimum amount of benzene and eluted with benzene-ethyl acetate mixtures through a silica-gel column. The fractions containing the product were combined and evaporated in vacuo. The residue was recrystallized from hexane giving 15.5 g (60~) of white crystalline material; m.p. 144-146C.
Preparation of Coupler #l .~
To a stirred solution of 7.0 g (0.01 mol) of compound IV
in 35 ml of tetrahydrofuran (THF) was added dropwise under a nitrogen atmosphere 12 ml (1.0 M solution in THF) of S,S'-carbonyl-di-l-phenyl-5-mercaptotetrazole. The reaction mixture was stirred for 2 hours, poured into ice-water and extracted with ethyl acetate. The extracts were dried over magensium sulfate and evaporated in vacuo. The pale yellow residue was recrystallized from ethyl acetate-ligroine yielding 5.0 g ~56~) of pure colorless long needles;

m.p. 114-117C.

Using a similar reaction scheme Coupler #2 was ~I prepared:
:.

C 1~ NHCOfHO~C5Hll-t CH3 ~ 2 5 CsHll-t s ~7~

2C4H0 ~3 Coupler #2 ~39-113'~818 ~, N
O
Z

ol; ~ ~ N
0=~ N
0 ~ ~ _ ~N ~ ~

O O 0~ 0--~ ~N

N

~ C,)~ =~_o~

: :: :

1~3~i8 Preparation of Compound III

To a solution of 16.0 g (0.055 mol) of 2-N-ethyl trifluoroacetamido-methyl-4-nitrophenol in 250 ml acetonitrile was added with stirring 7.10 g (0.055 mol) of di-i~opropyl ethylamine and 30.4 g (0.050 mol) of a-pivalyl-a-chloro-[2-chloro-5-y(2,4-di-tert-amylphenoYy)butylamido]acetanilide~

The mixture was heated on a steam bath for 1-1/2 hours. The solvent was evaporated in vacuo yielding a yellow oil. The oil was taken up in 200 ml of methanol and reacted with a solution of 20 g (0.5 mol) of sodium hydroxide in 50 ml of water. After stirring for 1 hour, the dark red solution was poured into 800 ml of ice water and 200 ml of concentrated hydrochloric acid. The solid was collected, triturated with ethyl acetate and then washed with ether. Yield of the desired amine hydro-chloride salt was 35.8 g (89~), m.p. 184-186 C.
Preparation of Coupler #3 To a mixture of 18.5 g (0.023 mol) ofcompound III
suspended in 300 ml of ethylacetate was added with vigorous stirring 150 ml of a saturated sodium bi-carbonate solution. When all the solid had dissolved, the organic phase was separated, dried over magnesium sulfate and filtered To the filtrate was added with stirring 8.8 g (0.023 mol) of S,S'-carbonyldi-l-phenyl-5-mercaptotetrazole prepared by bubbling phosgene into a benzene solution of l-phenyl-5-mercaptotetrazole. The reaction mixture w~s stirred for 30 minutes after which the solvent was evaporated in vacuo The residue was chromato-graphically separated with a silica-gel column using hexane-ethyl acetate mixtures as eluants. The fractions containing the pure product were combined and evaporated in vacuo to give 10 g .
.

113~18 (~5~) of Coupler #3; m.p. 77-80C.
Preparation of Coupler #4 -Coupler #4 was prepared by the catalytic reduction of Coupler #3 using 10~ Pd/C and reacting the resulting amine with acetic anhydride; m.p. 115-117 C.

Cl (CH3)3CCfHCONH ~
NHC(CN2)3O ~ 5Hll t 5Hll t ,~
CH2NI-c2H5 N - N
l~ lC--S~
NH~CH3 Coupler #4 .~ , 113 ~8il3 /~
~
r ~ ~
C ~

N C
C
S ~ r ~F~ ~ a~

h ~

:: O ~0 ~F

' ~ I , , 113~B18 ~s ' ' , ' g. ~ tc ,~ 5~ ~
, ., ,,~ .

~ ! ~

: -44-...... ` - -11 3 ~i 8 Preparation of Compound III
To a mixture of 26.7 g of compound I, 5.3 g of ~uccinlmide, lO drops of trifluoroacetic acid and 240 ml of di-n-butyl ether heated at 100-110C, was added with stirring 1.7 g Or paraformaldehyde. After heating for 1.5 hours, the mixtur.e was cooled and the solvent was removed on a rotary evaporator. The residue was taken up in dichloromethane and passed through a silica gel column to give 20 g of the succinimidomethyl derivative II.
The product obtained above was dissolved in lO0 ml of dimethylsulfoxide and warmed to 40C. With stirring, 4.0 g of sodium borohydride was added in portions It was then heated on a steam bath for 1 5 hours The mixture was cooled and poured cautiously with stirring into 1.2 liters ice-water and 40 ml acetic acid. The white solid was collected, dissolved in 600 ml of dlchloromethane, dried over MgS04, filtered and the filtrate passed through a short silica gel column using dichloromethane as the eluant- The solvent was removed under reduced pressure, and the residue was recrystallized from acetonitrile to give 10.7 g of pure compound III.
Preparation of Coupler #5 _ To a solution of 4.1 g of compound III in 60 ml of dried benzene was added with stirring 50 ml of 12~ solution of phosgene in benzene. The mixture was stirred at room temperature ~or 3 hours. The solvent was removed under reduced pressure. The carbamoyl chloride derivative IV thus obtained was dissolved in 20 ml tetrahydrofuran and added to a ~olution of 5 9 g of indophenol dye ~ in 50 ml of dried pyridine. The reaction mixture was ~tirred at room temperature for one hour and then heated on a steam bath overnight The solvent was removed under reduced pressure givlng an orange residue. It was 1~ ' , . . . ~ ., .

i~l3~

taken up in benzene, and chromatographically separated with a silica gel column eluting first with benzene, then with benzene-ethyl acetate solvent mixtures. The fractions con-taining the pure coupler were combined and the solvent removed in vacuo to give 2.6 g of coupler #5.
Using the same reaction scheme Coupler #6 was prepared:

Cl ~

CH3 ~ C5Hll-t ~ ~3 o~N-N~No2 C~ CR CH CR
2 2 ~ 2 3 ~Z~~

Coupler ~6 ~ ~2 ! . . i 113~818 ~ ~1 o ~ ~N~
~d ~ ~ ~

~

'o ~_ a~ N

, 113~18 Preparation of Compound V
To a stirred solution of 7.62 g of sulfanilic acid ln 40 ml 2N hydrochloric acid was added dropwise, at 0-5C, an ice-cold solution of 3.04 g of NaN0~ in 20 ml water. The diazonium salt solution thus obtained was added dropwise to a solution of 6.14 g of 2-cyano-6-chlorophenol in 50 ml pyridine, maintaining the reaction temperature below 10C. After the addition, the mlxture was allowed to warm up slowly to room temperature, stirred for 2 more hours, and then cooled in an ice bath. The bright yellow solid which separated out was collected, washed with ice-cold water followed by cold acetone.
Yield of the crude yellow azo dye was 15.4 g.
The product obtained above was added in small portionE to a stirred eolution of 500 g of thionyl chlorlde and 100 ml N,N-dimethylformamide at 0-5 C The mixture was stirred at this temperatu~e for 4 hours and then poured into ice water. The orange solid which separated out was collected, washed twice with cold dilute hydrochloric acid and dried, dissolved in 700 ml ethyl acetate, drled over Na2S04, filtered, and the solvent removed under reduced pressure to give 13 g of product; m.p. 209-211C.
The azophenol sulfonyl chloride derivative was added with stirring to a solution of 16 g of 2-tetradecyl-oxyaniline in 300 ml tetrahydrofuran and 50 g of di-iso-propylethylamine at 0-5C. After the addition, the mixture was ~tirred at room temperature for 2 hours. It was poured lnto ice-water containing 100 ml concentrated hydrochloric acid. The solid was collected, washed with water, and dried.
The crude dye was dlssolved in 50 ml CHC13 ~nd j . .. . . . .

~13g818 chromatograph~cally separated with a silica gel column using a CHC13- ethyl acetate-acetic acid solvent mixture as eluant.
A yield of 12 g of pure Compound V was obtained; m p. 98-100C.
Preparation of Coupler #7 To a suspensicn of 12 g o~ Compound III of Example 2 in 500 ml benzene was added with stirring 100 ml of saturated NaHC03 solution. After stirring for 3 hours the organic phase was separated, dried over MgS04, filtered and the filtrate concentrated under reduced pressure to 100 ml. With stirring, 100 g of 12% solution of phosgene in benzene was added. The reaction mixture was stirred overnight, after which it was -concentrated to dryness under reduced pressure. The residue was taken up in 20 ml tetrahydrofuran and reac~ed with 10.3 g of azophenol dye V dissolved in 500 ml pyridine. The reaction mlxture was stirred at room temperature oYer the weekend It was poured into ice-water containing 60 ml concentrated hydrochloric acid. The brown solid was collected, washed with ` water, and dried. The crude coupler was dissolved in a minimum amount of CHC13 and purified by passing through a silica gel column using CHC13 and ethyl acetate as eluants. Yield of pure Coupler ~7: 9.2 g; m.p. 107-110C.
Using a similar procedure Coupler #Is 8, 9 and 10 were prepared:

(C~3)3CQ H~NH ~

CN
~C~Igl~C~/-N~I~

Xi ~1 113~318 n n n n ~5~8 y - I N ~
y ~t V ~ ~
~o V V
~ ~=0 X I ~ N $

:~ h ~ o~ O
~ V

-5o-1134~18 Q) 5 ` , E t.) ~~

C~ 5 C~
O ~ e, b ' V 0~5 ~c.lq a X~ -51-113~8i8 Preparation of ComPounds II and III
To a mixture of 26.7 g of compound I, 5.3 g of succin~mide, 10 drops of trifluoroacetic acid and 240 ml of di-n-butyl ether heated at 100-110C, was added with stirring 1.7 g of paraformaldehyde. After heating for 1.5 hours, the mixture was cooled and the solvent was removed. The residue was taken up in dichloromethane and passed through a silica gel column to give 20 g of the succinimidomethyl derivative, compound II.
Compound II was dissolved in 100 ml of dimethyl-sulfoxide and warmed to 40 C. With stirring, 4.0 g of sodium borohydride was added in portions. It was then heated on a steam bath for 1.5 hours. The mixture was cooled and poured cautiously with stirring into 1.2 liters of ice water and 40 ml acetic acid. The white solid was collected, dissolved in 600 ml of dichloromethane, dried over MgS04 and filtered.
The filtrate was passed through a short silica gel column using dichloromethane as the eluant. The solvent was removed under reduced pressure, and the residue was recrystallized from acetonitrile to give 10.7 g of pure compound III.
Preparation of Coupler ~4 To a stirred solution of 4.6 g of compound III and 1.14 g of quinoline in 50 ml of tetrahydrofuran was added a solution of 1.6 g of l-naphthylchloroformate in 20 ml tetrahydrofuran. The reaction mixture was stirred at ambient temperature for 3 hours, then poured into ice water containing

5 ml of concentrated HCl. The solid was collected, washed with water and dried. Recrystallization from acetonitrile gave 4.8 g of Coupler #14; m.p. l97-lg9oc.

Example 1 -- Controlled Release of a Development Inhibltor Four color photographic elements illustrated by the rollowing schematic ~tructure were prepared. The numerical values denote quantities in g/m .

Gelatin - o.86 AgX as Ag - 1.35; Cyan Dye Forming Coupler - 0,70, DIR Coupler - See below, Gelatin - 2.7 /////////////Film Support///////////// .-The cyan dye forming coupler has the ~tructure:

~ eNH(CH2)40 ~ 5Hll t The element6 contained development inhibitor releasing couplers as follows:

Element Coupler g/m2 mol/m2 -~
A (control) None - - -(control) A* 0.193 2.6 x 10 4 C (lnventlon) #3 0.251 2.6 x 10 4 D (invention) #4 0.254 2.6 x 10 4 *Coupler A has the structure:

O O C~, ' (CH3)3c-clcHcNH ~ 0 N Nl ~ CSH11-t N - N

~. ~

, 1136~18 The four elements were exposed through a graduated-density test object, color developed ln the composition de&cribed below for 2-1/2 minutes at 38C, bIeachedJ fixed, and washed Composition of Color Developer Solution:
Water Diaminopropanol tetraacetic acid2.5 g Hydroxylamine sulfate 2.0 Na2S03 ( anhydrouS ) g 4-Amino-3-methyl-N ethyl-N-~-hydroxy-ethylaniline sulfate 4.5 e K2C03 (anhydrous) 37 5 NaEr 1.4 g KI 0.002 g Water to 1 liter; pH 10.0 During color development oxidized color developing a~ent couples with the cyan dye forming coupler to produce cyan dye, and couples with DIR couplers A, 3 and 4 to produce yellow dye and release directly (coupler A) or indirectly (couplers 3 and 4) a development inhibitor. The release of development inhibitor during the course of color development affects the production of oxidized color developing agent, and hence affects the amount of dye produced. The effect is measured by plotting the density to red light (i e., the density of the cyan dye produced) of each of the elements. These plots are shown in Figure 1. It will be observed th~t for equivalent exposures the cyan density obtained with Element C is less than that obtained with control Element B and that the cyan density obtained with 'I
Element D ls greater than that obtained with control Element B.

~, .

.

1~3g818 ThiE illustrates that merely by varying the timing ~roup the time and rate of release of a development inhi~itor can be controlled so that lt can be relsased more rapidly (Element C) or more slowly (Element D) than the same development lnhibitor released directly (Element B) from essentially the same coupler moiety.
Example 2 -- Interima~e Effectc.
Eive color photographic elements illustrated by the follo~ing schematic structure were prepared. The numerical values denote quantities in g/m2.

Gelatin - o.86 Green-sensiti~e AgBrl - 1.6; Gelatin -2.41; Cyan dye-forming coupler - 0.47;
DIR cou~ler - See below Antistain agent - 2,5-Didodecylhydro-quinone - 0,14; Gelatin - 0.5 Red-sen~itlve AEBrI - 1.6; Gelatin -2.41; Yellow dye-forming coupler -1.94 //'///////////Film Support ///////////

The cyan dye-forming coupler was the same coupler - as employed in the elements of Example 1. The yellow dye-for~..in~ coupler has the structure:
O ,0, .1 ~

NHS02Cl6H33 n liO

_~

~g ;

. . :

113~3i8 The elements contained development inhibitor releasing couplers as follows:

Elemenl, Coupler ~/m2 mol/m2 E None - -F A (see Ex. 1)0.09 1.4 x 10 4 G 11 0.31 3.5 x 10 4 H 12 0.09 1.0 x 10 4 I 13 0.29 3.3 x 10 4 The amount of development inhibitor releasing coupler incorporated in each of the elements was chosen to provide cyan dye curves having essentially equal slopes.
Couplers 11, 12 and 13 have the following structures:

(~ C5Hll-t O ICH(cH3)2~ N

NO~

Coupler #11 ; .' CONH ~

O
CH2N-CH(c~3)2 2 ~- N
. . .
Coupler #12 .

113~318 CONH(CH~)4~ ~ C5HIl-t ~21CH(CH3)2 Coupler #13 The five elements were exposed to green light through a graduated-density test object, then the test ob~ect was removed and the elements were uniformly flashed with red light. The elements were then color developed for 2 minutes at 38C using the composition described below, bleached, fixed and washed.
Composition of Color Developer Solution:
K2S03 2.0 g 4-Amino-3-methyl-N-ethyl-N-~-hydroxyethylaniline sulfate 3.55 g K2C03 (anhydrous) 30.0 g KBr 1.25 g KI 0. ooo6 g Water to 1 llter pH to 11.0 During color development oxidized color developing agent generated ln the green-sensltive layer (which has been stepwise exposed) couples with the cyan dye-~orming coupler and the DIR coupler to form cyan dye and release directly (Coupler A) or lndirectly (Couplers 11, 12 and 13) a development inhibitor. Oxidized color developing agent generated ln the red-,- ~

113~1B
sensitive layer (which has been uniformly exposed) couples with the yellow dye-forming coupler to form yellow dye. Development inhibitor released from the couplers migrates ~hrough the element until, in its active form, it inhibits silver halide development and affects the amount of dye formed in both of the layers. The effect on the red sensitive layer is proportional to the amount of development inhibitor released in the green-~ensitive layer and depends upon the amount of active develop-ment inhibitor reaching it. These effects are measured by plotting the densities of cyan dye (in the green-sensitive layer) and yellow dye (in the red-sensitive layer). These plots are shown in Figures 2-6. It will be observed that in each of Elements F-I, which contained development inhibitor releasing couplers, less yellow dye is ~ormed in proportion to green exposure than in Element E which did not contain such a coupler; and that in ~lements G-I, which contained couplers of this invention, significantly less yellow dye is formed in proportion to green exposure than in Element F, which contained a prior art coupler. This indicates that a greater amount of active development inhibitor is reaching the red-sensitive layer when couplers of this invention are employed than reaches the red-sensitive layer when couplers of the prior art are employed and results in greater interimage effects.
_xample 3 - Release of a Yellow Image Dye Three color photographic elements lllustrated by the-following schematic structure were prepared. The numerical values denote quantities in g/m2.

. .

113~18 Gelatin - 0.54 Gelatin - 2.70; AgX As Ag - 1.62;
Yellow dye-forming coupler - See below; Di-n-~utyl phthalate - 0,5 (g/
B Coupler) ////////////Film Support////////////

Element Coupler g/m2 mol/m2 J (control) B 1.3 0.0158 K (control) B o.65 o.oo78 L 7 0.65 0.0038 Coupler B has the structure:

C~l (C~3)3CCOCI ~CONR~' NHcO~c~2)3o ~ CS~ t C5Hll-t ~ .
COOH

The elements were exposed through a graduated-~ density test ob~ect, and processed at 38C according to the ;; following sequence:

:`
:

.

~3~818 Processi~ Sequence:

Color Developer ------------------------------------ 2' Water 4.3 g 4~Amino-3-methyl-N-ethyl-N-B-hydroxy-ethylaniline sulfate 0.1 ml H SO
2.0 g Sodi~m hexametaphosphate 4.0 g Na2S3 20.0 g Na CO H 0 2.0 g KB2r 3 2 - Water to 1 liter, pH 11 Fix ------------------------------------------------ 2' 800 ml Water 240 g Na2S O3-5H2O
15 g Na S~
48 ml 28~ Acetic Acid 7.5 g H BO
15 g Potassium Alum Water to 1 liter, pH 4.25 Bleach --------~------------------------------------ 2' 21.5 g NaBr 100.0 g K Fe(CN) 0.07 g NaH PO H O
Water to 1 l~te~, pH to 7.0 ~ Wash ----------------------------------------------- 2' : Fix ------------------------------------------------ 2' tsame as above) ; Wash ----------------------------------------------- 2' Stabilizing SGlution ------------------------------- 2' 5 g Cetyl trimethyl ammonium bromide : 20 g Na2CO3 Water to 1 liter, pH 11 ~: ~ash -----------------------------------------------10' .
`~ The resulting yellow dye images were evaluated by plot-ting yellow dye density vs. exposure. The results are shown in Figure 7. It will be observed that Element L, of the invention, yielded significantly more dye density than the elements con-taining prior art dyes, even though it contained less yellow coupler.

~,~

, : , 113~818 Example 4 - Release of a Cyan Image Dye Three color photographic elements illustrated by the following ~chematic structure were prepared. The numerical value denote quantities ln g/m2.

.
Gelatin - 0.54; Hardener - 0.081 Red-sensitive AgX as Ag - 1.08; Cyan dye-forming coupler - See below;
2,4-di-n-amylphenol ~ 0.5 (g/g coupler), Gelatin - 2.70 /////////////Film Support/////////////
Element Coupler g/m2 mol/m2 . C 0.86 0.0149 N C 0.43 0.0075 O #5 1.40 0.0075 Coupler C has the structure:

OH C,2H5 Cl ~ NHCOCHO ~ 5H11-t ; CH3 ~ 5 11 Cl The elements were exposed and processed as ln Example 3, except that the development was for 20 minutes at 20C in the following composition and that elements M and N
~20 were not treated in the cetyl trimethyl ammonium bromide solution:
:

; -- ' ~ '''-:

113~B18 Composition of Color Developin~ Solutlon:
Water K2S03 2.0 g 4-Amino-3-methyl-N-ethyl-N-~-(methanesulfonamido)ethyl-aniline ~ul~te hydrate 5,0 g Anhydrous K2C03 3 g KBr 1.25 B
XI 0, ooo6 g ~
Water to 1 liter pH to 11 The resulting cyan dye lmages were evaluated by plotting cyan dye density vs, exposure. The results are shown in Figure 8. It will be observed that Element 0, .
according to this invention, yielded 6ubstantially more dye than Element N, which contained an equimolar amount of a prior art coupler.
Example 5 - Release o~ a Competing Coupler Three color photographic elements illustrated by the following schematlc structure were prepared, The numerical values denote quantity in g/m2.

Gelatin - 1.08 Ag3rl emulsion - see below / Coupler -see below / Tri-cresyl phosphate - 0.5 Lg/g coupler); Gelatin 3.24 Antihalation layer / / / / / Film Support / / / / / / / /

.
, ' ` ' ' ~' ' ' .

113~3i8 Cyan Dye- Coupler Forming 2 2 Element AgBrI as Ag Coupler g/m mols/m P control 1.08 C (See Ex4)0.26 0.052 Q l.o8 14 o.48 0.052 X 3.24 14 o.48 0.052 Each element was exposed for 1/25 of Q second through a neutral graduated-density test ob~ect and then processed at 38C according to the following sequence.

10Processlng Sequence:
Color developer ,.,.,,,.,,,,..,,.,,,..,,,,,,1' 2.0 g K2so3 2,45 g 4-Amino-3-methyl-N,N-dlethyl-anlllne hydrochloride 30,0 ~ K2C03 (anhydrous) `~ . 1.25 ~ KBr 0,00~6 ~ KI
Water to 1 liter pH to 10.0 10% Acetlc ~cld Stop ....................... 4' Bleach...................................... 4' 175 ml 1.56 Molar Ammonium Ferric Ethylenediamine tetraacetic acid 150 g NH Br 10.5 ml Ac~tic Acid 35 g NaNO
Water t~ 1 liter Wash,....................................... 3' Fix......................................... 4' 30162 ml 60% Ammonium thiosulphate solution 13 g Sodium Hydrogen Sulfite 2.83 ml 50% NaOH Solution Water to 1 liter Wash,....................................... 3' Stabilizer.................................. l' 10.0 ml 10% Wetting Agent

6.o ml 35% Formalin Water to 1 liter ` -63-(l :.

1:13~&~8 The resulting cyan dye images were evaluated by plotting cyan dye density vs exposure. The results are shown in Figure 9. It will be observed that for equivalent amounts of silver (Elements P and Q) less dye density was obtained with a coupler of this invention than with a prior art coupler. In order to obtain equivalent density with a coupler of this invention approximately three times as much silver halide was required (Element R). Both of these observations indicate that competing coupler was being released and was competing for oxidized color developing agent with the cyan dye forming coupler.
This invention has been described in detail with particular reference to preferred embodiments thereof, but it will be urlderstood that variations and modifications can be effected within the spirit and scope of the invention.

Claims (51)

We Claim:

1. A photographic element comprising a support, at least one photosensitive silver halide emulsion layer and a photographic coupler containing a timing group which is cleaved from the coupler as a result of reaction of the coupler with oxidized color developing agent and thereafter undergoes an intramolecular nucleophilic displacement reaction to make available a photographically useful group.

2. A photographic element comprising a support, at least one photosensitive silver halide emulsion layer and a photographic coupler containing a timing group between a coupler moiety and a photographically useful group, the coupler moiety being joined to the timing group and the timing group being Joined to the photographically useful group so that upon reaction of the coupler with oxidized color developing agent, the timing group and the photographically useful group are released as a unit from the coupler moiety and thereafter the photographically useful group is released from the timing group by an intramolecular nucleophillic displacement reaction.

3. A photographic element comprising a support, at least one silver halide emulsion layer and a photographic coupler containing a coupler moiety, a photographically useful group, and a timing group Joining the coupler moiety and the photographically useful group, the timing group comprising a nucleophillic group attached to the coupler moiety at a position from which it is displaced as a result of reaction of the coupler moiety with oxidized color developing agent, an electrophillic group attached to the photographically useful group, and a linking group spatially relating the nucleophillic group and the electrophillic group to undergo, after cleavage of the timing group and the photographically useful group from the coupler moiety, an intramolecular nucleophilic displacement reaction which cleaves the photo-graphically useful group from the timing group.

4. A photographic element comprising a support, at least one silver halide emulsion layer and a photographic coupler represented by the structure:
where:
COUP is a coupler moiety;
PUG is a photographically useful group;
Nu is a nucleophilic group attached to a position on COUP from which it will be displaced upon reaction of COUP
with oxidized color developing agent;
E is an electrophillic group, and X is a linking group for spatially relating Nu and E, upon release of Nu from COUP, to undergo an intramolecular nucleophilic displacement reaction with the formation of a three- to seven-membered ring and thereby release PUG.

5. A photographic element of claim 4 wherein COUP
is a coupler moiety which yields a colored product on reaction with oxidized color developing agent.

6. A photographic element of claim 4 wherein COUP
is a coupler moiety which yields a colorless product on reaction with oxidized color developing agent.

7. A photographic element of claim 4 wherein Nu is selected from the group consisting of -O-(CR)n-, -S-(CR2)n-, -?-, , , , , , , , , , , and , E is selected from the group consisting of , , , , , , , , , , , , and ;

where each R is independently hydrogen, alkyl of 1 to 20 carbon atoms or aryl of 6 to 20 carbon atoms, and n is an integer of from 0 to 4 such that the ring formed by Nu, X and E upon nucleophilic attack of Nu upon the electrophilic center of E contains 3 to 7 ring atoms.

8. A photographic element of claim 4 wherein PUG
is a development inhibitor.

9. A photographic element of claim 4 wherein PUG
is a dye or dye precursor.

10. A photographic element of claim 4 wherein PUG
is a coupler.

11. A photographic element of claim 4 wherein PUG
is a developing agent.

12. A photographic element of claim 4 wherein PUG
is a bleach inhibitor.

13. A photographic element comprising a support and at least one silver halide emulsion layer having associated therewith a photographic coupler represented by the formula:
where:
COUP is a coupler moiety;
Nu is a nucleophilic group attached to the coupling position of COUP, selected from the group consisting of -0-, where R is hydrogen or alkyl of 1 to 20 carbon atoms;
Z represents the atoms necessary to complete a mono- or bicyclic aromatic or heterocyclic ring system containing 5 to 10 ring atoms;

E is an electrophilic group selected from the group consisting of , , , and ;
where each R is independently hydrogen or alkyl of 1 to 20 carbon atoms;
n is an integer of 0 to 4 such that the ring formed upon reaction of the nucleophilic center of Nu with the electrophilic center of E contains 5 to 7 members, and PUG is a photographically useful group attached to a position on E from which it will be displaced upon nucleophilic attack of Nu at the electrophilic center in E.
14. A photographic element of claim 13 wherein COUP is a coupler moiety which yields a colored product on reaction with oxidized color developing agent.

14. A photographic element of claim 13 wherein

COUP is a coupler moiety which yields a colorless or neutral product on reaction with oxidized color developing agent.

16. A photographic element comprising a support having thereon a red-sensitive silver halide emulsion unit having associated therewith a cyan-dye-image-providing material, a green-sensitive silver halide emulsion unit having associated therewith a magenta-dye-image-providing material, and a blue-sensitive silver halide emulsion unit having associated therewith a yellow-dye-image-providing material, at least one of the silver halide emulsion units having associated therewith a photographic coupler containing a timing group between a coupler moiety and a photographically useful group, the coupler moiety being joined to the timing group and the timing group being joined to the photographically useful group so that upon reaction of the coupler with oxidized color developing agent, the timing group and the photographically useful group are released as a unit from the coupler moiety and thereafter the photographically useful group is released from the timing group by an intramolecular nucleophilic displacement reaction.

17. A photographic element of claim 16 wherein the photographic coupler contains a coupler moiety, a photographically useful group, and a timing group joining the coupler moiety and the photographically useful group, the timing group comprising a nucleophilic group attached to the coupler moiety at a position from which it is displaced as a result of reaction of the coupler moiety with oxidized color developing agent, an electrophilic group attached to the photographically useful group, and a linking group spatially relating the nucleophilic group and the electrophilic group to undergo, after cleavage of the timing group and the photographically useful group from the coupler moiety, an intramolecular nucleophilic displacement reaction which cleaves the photo-graphically useful group from the timing group.

18. A photographic element of claim 16 wherein the photographic coupler is represented by the structure where:
COUP is a coupler moiety;
PUG is a photographically useful group;
Nu is a nucleophilic group attached to a position on COUP from which it will be displaced upon reaction of COUP
with oxidized color developing agent;
E is an electrophilic group; and X is a linking group for spatially relating Nu and E, upon release of Nu from COUP, to undergo an intramolecular nucleophilic displacement reaction with the formation of a three- to seven-membered ring and thereby release PUG.

19. A photographic element of claim 18 wherein Nu is selected from the group consisting of , , , , , , , , , , , and , E is selected from the group consisting of , , , , , , , , , , , , , anad ;
where each R is independently hydrogen, alkyl of 1 to 20 carbon.
atoms or aryl of 6 to 20 carbon atoms, and n is an integer of from 0 to 4 such that the ring formed by Nu, X and E upon nucleophilic attack of upon the electrophilic center of E contains 3 to 7 ring atoms.

20. A photographic element of claim 16 wherein the photographic coupler is represented by the structure where:
COUP is a coupler moiety;
Nu is a nucleophilic group attached to the coupling position of COUP, selected from the group consisting -O-, -O-CR2-, , , -S-, -S-CR2- and where R is hydrogen or alkyl of 1 to 20 carbon atoms;
Z represents the atoms necessary to complete a mono- or bicyclic aromatic or heterocyclic ring system containing 5 to 10 ring atoms;
E is an electrophilic group selected from the group consisting of , , , and where each R is independently hydrogen or alkyl of 1 to 20 carbon atoms;
n is an integer of 0 to 4 such that the ring formed upon reaction of the nucleophilic center of Nu with the electrophilic center of E contains 5 to 7 members, and PUG is a photographically useful group attached to a position on E from which it will be displaced upon nucleophilic attack of Nu at the electrophilic center in E.

21. A photographic element of claim 20 wherein PUG
is a development inhibitor.

22. A photographic element of claim 20 wherein PUG
is a dye or dye precursor.

23. A photographic element of claim 20 wherein PUG is a coupler.

24. A photographic element of claim 20 wherein PUG is a developing agent.

25. A photographic element of claim 20 wherein PUG is a bleach inhibitor.

26. A photographic element comprising a support having thereon a red-sensitive silver halide emulsion unit having associated therewith a cyan-dye-forming coupler, a green-sensitive silver halide emulsion unit having associated therewith a magenta-dye-forming coupler, and a blue-sensitive silver halide emulsion unit having associated therewith a yellow-dye-forming coupler at least one of the silver halide emulsion units having associated therewith a photographic coupler represented by the formula where:
COUP 18 a coupler moiety;

\
Nu is a nucleophilic group attached to the coupling position of COUP, selected from the group consisting of , , , -S-, . and where R is hydrogen or alkyl of 1 to 20 carbon atoms;
Z represents the atoms necessary to complete a mono-or bicyclic aromatic or heterocyclic ring system containing 5 to 10 ring atoms;
E is an electrophilic group selected from the group consisting of , , , and where each R is independently hydrogen or alkyl of 1 to 20 carbon atoms, n is an integer of 0 to 4 such that the ring formed upon reaction of the nucleophilic center of Nu with the electrophilic center of E contains 5 to 7 members; and PUG is a development inhibitor attached to a position on E from which it will be displaced upon nucleo-philic attack of Nu at the electrophilic center in E.

27. A photographic element of claim 26 wherein COUP is a coupler moiety which yields a colorless product on reaction with oxidized color developing agent.

28. A photographic element of claim 26 wherein COUP is a coupler moiety which yields a colored product on reaction with oxidized color developing agent.

29. A photographic element of claim 28 wherein the photographic coupler and the dye forming coupler yield dyes of essentially the same color on reaction with oxidized color developing agent.

30. A photographic element of claim 28 wherein the photographic coupler and the dye forming coupler yield dyes of different color on reaction with oxidized color developing agent.

31. A photographic element comprising a support having thereon a red-sensitive silver halide emulsion unit having associated therewith a cyan-dye-forming coupler, a green-sensitive silver halide emulsion unit having associated therewith a magenta-dye-forming coupler and a blue-sensitive silver halide emulsion unit having associated therewith a yellow-dye-forming coupler, at least one of the silver halide emulsion units having associated therewith as a dye forming coupler a photographic coupler represented by the formula where:
COUP is a coupler moiety;
Nu is a nucleophilic group attached to the coupling position of COUP, selected from the group consisting of -O-, -O-CR2-, ,, -S-, -S-CR2- and where R is hydrogen or alkyl of 1 to 20 carbon atoms;

Z represents the atoms necessary to complete a mono- or bicyclic aromatic or heterocyclic ring system containing 5 to 10 ring atoms;
E is an electrophilic group selected from the group consisting of ,,, and where each R is independently hydrogen or alkyl of 1 to 20 carbon atoms;
n is an integer of 0 to 4 such that the ring formed upon reaction of the nucleophilic center of Nu with the electrophilic center of E contains 5 to 7 members; and PUG is a dye or dye precursor attached to a position on E from which it will be displaced upon nucleo-philic attack of Nu at the electrophilic center in E.

32. A photographic element of claim 31 wherein PUG is a dye precursor which on release from E in an alkaline photographic processing composition yields a dye of essentially the same color as the dye formed by reaction of COUP with oxidized color developing agent.

33. A photosensitive silver halide emulsion containing a photographic coupler having a timing group which is cleaved from the coupler as a result of reaction of the coupler with oxidized color developing agent and thereafter undergoes an intramolecular nucleophilic displacement reaction to make available a photographically useful group.

34. A photosensitive silver halide emulsion containing a photographic coupler having a timing group between a coupler moiety and a photographically useful group, the coupler moiety being joined to the timing group and the timing group being joined to the photographically useful group so that upon reaction of the coupler with oxidized color developing agent, the timing group and the photographically useful group are released as a unit from the coupler moiety and thereafter the photographically useful group is released from the timing group by an intramolecular nucleophilic displacement reaction.

35. A silver halide emulsion containing a photo-graphic coupler having a coupler moiety, a photographically useful group, and a timing group joining the coupler moiety and the photographically useful group, the timing group comprising a nucleophilic group attached to the coupler moiety at a position from which it is displaced as a result of reaction of the coupler moiety with oxidized color developing agent, an electrophilic group attached to the photographically useful group, and a linking group spatially relating the nucleophilic group and the electrophilic group to undergo, after cleavage of the timing group and the photographically useful group from the coupler moiety, an intramolecular nucleophilic displacement reaction which cleaves the photographically useful group from the timing group.

36. A photographic silver halide emulsion containing a photographic coupler represented by the structure:
where:
COUP is a coupler moiety;
PUG is a photographically useful group;
Nu is a nucleophilic group attached to a position on COUP from which it will be displaced upon reaction of COUP
with oxidized color developing agent;
E is an electrophilic group; and X is a linking group for spatially relating Nu and E, upon release of Nu from COUP, to undergo an intromolecular nucleophilic displacement reaction with the formation of a three- to seven-membered ring and thereby release PUC.

37. A photographic silver halide emulsion containing a photographic coupler represented by the formula:
where:
COUP is a coupler moiety;

NU is a nucleophilic group attached to the coupling position of COUP, selected from the group consisting of -O-, -O-CR2-,,,-S-, -S-CR2- and where R is hydrogen or alkyl of 1 to 20 carbon atoms;
Z represents the atoms necessary to complete a mono- or bicyclic aromatic or heterocyclic ring system containing 5 to 10 ring atoms;
E is an electrophilic group selected from the group consisting of , , , and where each R is independently hydrogen or alkyl of 1 to 20 carbon atoms;
n is an integer of 0 to 4 such that the ring formed upon reaction of the nucleophilic center of Nu with the electrophilic center of E contains 5 to 7 members; and PUG is a photographically useful group attached to a position on E from which it will be displaced upon nucleophilic attack of Nu at the electrophilic center in E.

38. A process of forming a photographic image which comprises developing an exposed silver halide emulsion layer with a color developing agent in the presence of a photographic coupler containing a timing group which is cleaved from the coupler as a result of reaction of the coupler with oxidized color developing agent and thereafter undergoes an intramolecular nucleophilic displacement reaction to make available a photographically useful group.

39. A process of forming a photographic image which comprises developing an exposed silver halide emulsion layer with a color developing agent in the presence of a photographic coupler containing a timing group between a coupler moiety and a photographically useful group, the coupler moiety being joined to the photographically useful group so that upon reaction of the coupler with oxidized color developing agent, the timing group and the photographically useful group are released as a unit from the coupler moiety and thereafter the photographically useful group is released from the timing group by an intramolecular nucleophilic displacement reaction.

40. A process of claim 39 wherein the photographic coupler contains a coupler moiety, a photographically useful group, and a timing group joining the coupler moiety and the photographically useful group, the timing group comprising a nucleophilic group attached to the coupler moiety at a position from which it is displaced as a result of reaction of the coupler moiety with oxidized color developing agent, an electrophilic group attached to the photographically useful group, and a linking group spatially relating the nucleophilic group and the electrophilic group to undergo, after cleavage of the timing group and the photographically useful group from the coupler moiety, an intramolecular nucleophilic displacement reaction which cleaves the photographically useful group from the timing group.

41. A process of claim 39 wherein the photographic coupler is represented by the structure:
where:
COUP is a coupler moiety;
PUG is a photographically useful group;
Nu is a nucleophilic group attached to a position on COUP from which it will be displaced upon reaction of COUP
with oxidized color developing agent;
E is an electrophilic group, and X is a linking group for spatially relating Nu and E, upon release of Nu from COUP, to undergo an intromolecular nucleophilic displacement reaction with the formation of a three- to seven-membered ring and thereby release PUG.

42. A process of claim 41 wherein Nu is selected from the group consisting of -O-(CR2)n-, -S-(CR2)n-, , , , , , , , , , , and , E is selected from the group consisting of , , , , , , , , , , , , , and ;

where each R is independently hydrogen, alkyl of 1 to 20 carbon atoms or aryl of 6 to 20 carbon atoms, and n is an integer of from 0 to 4 such that the ring formed by Nu, X and E upon nucleophilic attack of Nu upon the electrophilic center of E contains 3 to 7 ring atoms.

43. A process of claim 39 wherein the photographic coupler is represented by the formula where:

COUP is a coupler moiety;
Nu is a nucleophilic group attached to the coupling position of COUP, selected from the group consisting of -O-, -O-CR2-, , , -S-, -S-CR2- AND where R is hydrogen or alkyl of 1 to 20 carbon atoms;
Z represents the atoms necessary to complete a mono- or bicyclic aromatic or heterocyclic ring system containing 5 to 10 ring atoms;
E is an electrophilic group selected from the group consisting of , , , and where each R is independently hydrogen or alkyl of 1 to 20 carbon atoms;
n is an integer of 0 to 4 such that the ring formed upon reaction of the nucleophilic center of Nu with the electrophilic center of E contains 5 to 7 members; and PUG is a photographically useful group attached to a position on E from which it will be displaced upon nucleophilic attack of Nu at the electrophilic center in E.

44. A process of claim 43 wherein the photographic coupler is contained in the photographic element.

45. A process of claim 44 wherein the photographic coupler is contained in a processing solution with the color developing agent.

46. A photographic coupler containing a timing group which is cleaved from the coupler as a result of reaction of the coupler with oxidized color developing agent and thereafter undergoes an intramolecular nucleophilic displacement reaction to make available a photographically useful group.

47. A photographic coupler containing a timing group between a coupler moiety and a photographically useful group, the coupler moiety being the timing group and the timing group being joined to the photographically useful group so that upon reaction of the coupler with oxidized color developing agent, the timing group and the photographically useful group are released as a unit from the coupler moiety and thereafter the photographically useful group is released from the timing group by an intramolecular nucleophilic displacement reaction

48. A photographic coupler containing a coupler moiety, a photographically useful group, and a timing group joining the coupler moiety and the photographically useful group, the timing group comprising a nucleophilic group attached to the coupler moiety at a position from which it is displaced as a result of reaction of the coupler moiety with oxidized color developing agent, an electrophilic group attached to the photographically useful group, and a linking group spatially relating the nucleophilic group and the electrophilic group to undergo, after cleavage of the timing group and the photographically useful group from the coupler moiety, an intramolecular nucleophilic displacement reaction which cleaves the photo-graphically useful group from the timing group.

49. A photographic coupler represented by the structure:

where:
COUP is a coupler moiety;
PUG is a photographically useful group;
Nu is a nucleophilic group attached to a position on COUP from which it will be displaced upon reaction of COUP
with oxidized color developing agent;
E is an electrophilic group; and X is a linking group for spatially relating Nu and E, upon release of Nu from COUP, to undergo an intramolecular nucleophilic displacement reaction with the formation of a three to seven-membered ring and thereby release PUG.

50. A photographic coupler of claim 49 wherein Nu is selected from the group consisting of , -S-(CR2)n-, , , , , , , , , , , -O-?- and , E is selected from the group consisting of -O-(CR2)N-, , , , , , , , , , , , , and ;

where each R is independently hydrogen, alkyl of 1 to 20 carbon atoms or aryl of 6 to 20 carbon atoms, and n is an integer of from 0 to 4 such that the ring formed by Nu, X and E upon nucleophilic attack of Nu upon the electrophilic center of E contains 3 to 7 ring atoms.

51. A photographic coupler represented by the formula:

where:
COUP is a coupler moiety;
Nu is a nucleophilic group attached to the coupling position of COUP, selected from the group consisting of -O-, -O-CR2-, , , -S-, -S-CR2- and where R 15 hydrogen or alkyl of 1 to 20 carbon atoms;
Z represents the atoms necessary to complete a mono- or bicyclic aromatic or heterocyclic ring system containing 5 to 10 ring atoms;
E is an electrophilic group selected from the group consisting of , , , and where each R is independently hydrogen or alkyl of 1 to 20 carbon atoms;
n is an integer of 0 to 4 such that the ring formed upon reaction of the nucleophilic center of Nu with the electrophilic center of E contains 5 to 7 members; and PUG is a photographically useful group attached to a position on E from which it will be displaced upon nucleophilic attack of Nu at the electrophilic center in E.