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Description  |
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This invention relates to a new photographic naphtholic coupler capable
upon oxidative coupling of forming a dye that is capable of being washed
out of the photographic material containing the coupler upon processing
and to photographic materials and processes comprising the naphtholic
coupler.
Various couplers are known in photographic materials and processes. One of
the classes of photographic couplers includes naphtholic couplers that
typically form cyan dyes upon oxidative coupling in photographic materials
and processes. These naphtholic couplers typically form cyan dyes upon
oxidative coupling with color developing agents. Such naphtholic couplers
are also known which are capable of forming dyes upon oxidative coupling
that can be washed out of the photographic material upon processing. These
naphtholic couplers are described in, for example, U.S. Pat. No.
4,482,629.
The naphtholic couplers that are capable of forming dyes that can be washed
out of the photographic material upon photographic processing contain a
water solubilizing group, such as a carboxy group or sulfonic acid group,
substituted on a group in the 2-position of the naphtholic coupler. It has
been desirable to provide a naphtholic coupler that is not as expensive to
manufacture as the described naphtholic couplers and still provides a
useful dye that can be washed out of the photographic material with the
added advantage that the coupler enables a lower concentration of coupler
to be used in a photographic element without significantly changing
imaging results.
It has also been desirable to provide such a naphtholic coupler that
contains a coupling-off group that enables desired acutance and desired
interimage effects in a color photographic silver halide material and
process at lower concentrations of coupler.
The present invention solves these problems by providing a photographic
element comprising a support bearing at least one photographic silver
halide emulsion layer and an immobile naphtholic coupler capable upon
oxidative coupling of forming a dye that is capable of being washed out of
the photographic element upon photographic processing, wherein the
immobile naphtholic coupler comprises a ballast free naphtholic coupler
moiety comprising a --CONH.sub.2 group in the 2-position and a ballasted
coupling-off group in the 4-position comprising a releasable development
inhibitor group. The ballasted coupling-off group preferably comprises a
releasable photographically useful group (PUG) that is a releasable
development inhibitor group.
The immobile naphtholic coupler is typically represented by the formula:
##STR1##
wherein Z is a ballasted coupling-off group that is a releasable
development inhibitor group, R.sub.1 is a ballast-free substituent that
does not adversely affect the desired properties of the coupler and dye,
and z is 0, 1, 2 or 3. R.sub.1 does not comprise a ballast group because
such a group adversely affects wash-out properties of the dye formed from
the naphtholic coupler.
The ballasted coupling-off group (Z) enables the naphtholic coupler to be
immobile in the photographic element prior to exposure and processing.
Upon exposure and processing of the described element the naphtholic
coupler reacts with oxidized color developing agent to form a dye that is
washed out of the element during processing. Also, the coupling-off group
is released during processing. The portion of the coupling-off group
containing the ballast group remains in the location in which it was
coated. The coupling-off group preferably comprises a releasable
photographically useful group (PUG) which is released upon photographic
processing. The PUG either is immobilized to remain in the location of the
element in which it was coated or the PUG is mobile to allow it, after
release, to move to a location in the element at which it can serve its
intended function.
A preferred naphtholic coupler as described comprises a coupling-off group
represented by the formula:
--(LINK).sub.n --(TIME).sub.m --PUG
wherein
TIME is a releasable timing group capable of being released from the LINK
moiety during photographic processing;
LINK is a releasable linking group capable of being released from the
naphtholic coupler moiety upon oxidative coupling of the naphtholic
coupler;
n and m individually are 0, 1 or 2;
PUG is a releasable photographically useful group that is a releasable
development inhibitor group; and, preferably,
at least one of n and m is 1 or 2.
A process of forming an image having the described advantages comprises
developing an exposed photographic element as described by means of a
color developing agent in the presence of the described naphtholic coupler
and washing-out the dye formed from the naphtholic coupler.
Any naphtholic coupler moiety is useful that can contain the --CONH.sub.2
group in the 2-position and a coupling-off group in the 4-position and can
form a compound, especially a dye, that can be washed out of the element
upon oxidative coupling of the coupler. It will be appreciated that
depending upon the particular developing agent and the particular type of
processing, the reaction product of the coupler moiety and the oxidized
developing agent can be colored or colorless. Examples of useful
naphtholic coupler moieties can be unsubstituted except for the required
substituents in the 2- and 4-positions as described. Optionally the
naphtholic coupler moieties in addition to the substituents in the 2- and
4-positions can contain other substituents that do not adversely affect
the desired properties of the element and coupler. Examples of such
substituents include 5-NHSO.sub.2 CH.sub.3, 5-NHCOCH.sub.3 or 6-NHSO.sub.2
CH.sub.3. Useful naphtholic coupler moieties include those described in,
for example, the following patents in which the group described in the
2-position is replaced with --CONH.sub.2 , especially those having a
ballasted coupling-off group: U.S. Pat. Nos. 4,840,884; 4,861,701;
2,474,293; 3,227,554; 4,482,629 and 4,857,447.
Any coupling-off group containing a ballast group known in the photographic
art is useful in the 4-position of the described naphtholic coupler
moiety. Examples of useful coupling-off groups are described in, for
example, U.S. Pat. No. 4,861,701. Preferred coupling-off groups are those
that enable release of a PUG upon photographic processing, especially
those that have a releasable timing group between the bond to the coupling
position of the coupler and the releasable PUG. Preferred timing groups
are described in, for example, U.S. Pat. Nos. 4,861,701; 4,248,962;
4,409,323; 4,482,629 and 4,857,447.
A preferred naphtholic coupler is represented by formula:
##STR2##
wherein
X represents the atoms completing a 5-, 6- or 7-member ring, such as an
aryl or heterocyclic group;
R.sub.1 is a ballast-free substituent;
z is 0, 1, 2 or 3;
BALL is a ballast group known in the photographic art;
T.sup.2 is a releasable timing group, such as a timing group described in
U.S. Pat. No. 5,021,322 and U.S. Pat. No. 5,026,628 of W. Begley et al.
R.sub.2 and R.sub.3 individually are hydrogen, unsubstituted or substituted
alkyl or aryl, such as alkyl containing 1 to 40 carbon atoms or aryl
containing 6 to 40 carbon atoms, such as a phenyl or naphthyl group; and,
q is 0, 1 or 2.
T.sup.2 is, for example, a group that enables release of PUG by means of
intramolecular nucleophilic displacement, such as described in U.S. Pat.
No. 4,248,962 and U.S. Pat. No. 4,861,701.
In the case of such couplers that release a PUG by means of a timing group,
reaction of the coupler with oxidized color developing agent cleaves the
bond between the coupler and the coupling-off group. Then the bond between
the PUG and the remainder of the coupling-off group is cleaved. Bond
cleavage between the PUG and the remainder of the coupling-off group
preferably does not involve the action of oxidized color developing agent.
The cleavage of the bond between the PUG and the remainder of the
coupling-off group can involve any reaction known in the photographic art
for cleavage of such groups, for example an intramolecular nucleophilic
displacement reaction or other elimination reaction.
Any ballast group known in the photographic art can be useful on the
coupling-off group. The ballast group (BALL) herein means an organic group
of such size and configuration as to confer on the coupler molecule
sufficient bulk to render the coupler substantially non-diffusible from
the layer in which it is coated in a photographic element prior to
exposure and processing. Representative ballast groups include substituted
or unsubstituted alkyl or aryl groups containing, for example, 8 to 40
carbon atoms. Other useful ballast groups include sulfonamido groups
containing 8 to 40 carbon atoms, carbonamido, carbamoyl, sulfamoyl, ester,
sulfone, ether, thioether and amino groups.
A typical timing group T.sup.2 is a group that enables release of a PUG by
means of intramolecular nucleophilic displacement, such as described in
U.S. Pat. Nos. 4,861,701; 4,857,440; 4,847,185 and 4,248,962. A preferred
timing group for T.sup.2 is described in U.S. Pat. No. 5,021,322 and U.S.
Pat. No. 5,026,628 of W. Begley et al, the disclosures of which are
incorporated herein by reference.
Illustrative timing groups T.sup.2 are as follows:
##STR3##
and other illustrative groups described in U.S. Pat. No. 4,857,447, the
disclosures of which are incorporated herein by reference.
In the above structures, R.sub.4, R.sub.5, R.sub.6, R.sub.6a, R.sub.7,
R.sub.8, R.sub.9, R.sub.10, R.sub.11, R.sub.12, R.sub.13, R.sub.14,
R.sub.15, R.sub.16, R.sub.17, R.sub.18, R.sub.19, R.sub.20, R.sub.21,
R.sub.22, R.sub.23 and R.sub.24 individually are hydrogen or substituents
that do not adversely affect the desired properties of the naphtholic
coupler or dye formed, such as unsubstituted or substituted alkyl, for
example, methyl, ethyl, propyl, n-butyl, t-butyl and eicosyl, or
unsubstituted or substituted aryl, such as phenyl, or substituted phenyl,
and PUG is a releasable photographically useful group. At least one of the
described groups on the coupling-off group is a ballast group.
As used herein the term "naphtholic coupler" refers to the entire compound
including the coupler moiety and the coupling-off group. The term
"naphtholic coupler moiety" herein refers to that portion of the coupler
other than the coupling-off group.
The PUG is preferably any development inhibitor group that is typically
made available in a photographic element in an imagewise fashion. The PUG
can be a photographic reagent or a photographic dye. A photographic
reagent herein is a moiety that upon release further reacts with
components in the photographic element, such as a development inhibitor, a
development accelerator, a bleach inhibitor, a bleach accelerator, a
coupler (for example, a competing coupler, a dye-forming coupler, or a
development inhibitor releasing coupler (DIR coupler)), a dye precursor, a
dye, a developing agent (for example, a competing developing agent, a
dye-forming developing agent, or a silver halide developing agent), a
silver complexing agent, a fixing agent, an image toner, a stabilizer, a
hardener, a tanning agent, a fogging agent, an ultraviolet radiation
absorber, an antifoggant, a nucleator, a chemical or spectral sensitizer
or a desensitizer.
The PUG can be present in the coupling-off group as a preformed species or
it can be present in a blocked form or as a precursor. The PUG can be for
example a preformed development inhibitor or the development inhibiting
function can be blocked by being the point of attachment to the carbonyl
group bonded to PUG in the coupling-off group. Other examples are a
preformed dye, a dye that is blocked to shift its absorption, and a leuco
dye.
A preferred naphtholic coupler as described is a photographic coupler
containing a naphtholic coupler moiety and a PUG containing a hetero atom
from VIb or Vb of the Periodic Table having a negative valence of 2 or 3
bonded to a carbonyl group of the coupling-off group.
Any couplers known to be useful in the photographic art can be used with
the described naphtholic couplers and in various locations known in the
art in a photographic element. There follows a listing of patents and
publications that describe representative couplers that can be useful in
combination with the described naphtholic couplers:
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. Pat. Nos. 2,772,162; 2,895,826; 3,002,836;
3,034,892; 2,474,293; 2,423,730; 2,367,531; 3,041,236; 4,333,999 and
"Farbkuppler-eine Literaturubersicht," published in Agfa Mitteilungen,
Band III, pp. 156-175 (1961).
Preferably such couplers are phenols and naphthols that form cyan dyes on
reaction with oxidized color developing agents.
B. Couplers which form magenta dyes upon reaction with oxidized color
developing agent are described in such representative patents and
publications as: U.S. Pat. Nos. 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 III, pp. 126-156 (1961).
Preferably such couplers are pyrazolones and pyrazolotriazoles that form
magenta dyes upon reaction with oxidized color developing agents.
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. Pat. Nos. 2,875,057; 2,407,210; 3,265,506;
2,298,443; 3,048,194; 3,447,928 and "Farbkuppler-eine Literaturubersicht,"
published in Agfa Mitteilungen, Band III, pp. 112-126 (1961).
Preferably such couplers are acylacetamides, such as benzoylacetanilides
and pivaloylacetanilides that form yellow dyes upon reaction with oxidized
color developing agents.
D. Couplers which form colorless products upon reaction with oxidized color
developing agent are described in such representative patents as: U.K.
Patent No. 861,138; U.S. Pat. Nos. 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 oxidized color
developing agent.
Any releasable PUG known in the photographic art is useful in the
coupling-off group as described. Examples of useful PUG's are as follows:
PUG's
A. PUG's which form development inhibitors upon release are described in
such representative patents as U.S. Pat. Nos. 3,227,554; 3,384,657;
3,615,506; 3,617,291; 3,733,201; 4,861,701 and U.K. Pat. No. 1,450,479.
Preferred development inhibitors are iodide and heterocyclic compounds
such as mercaptotetrazoles, selenotetrazoles, mercaptobenzothiazoles,
selenobenzothiazoles, mercaptobenzoxazoles, selenobenzoxazoles,
mercaptobenzimidazoles, selenobenzimidazoles, oxadiazoles, benzotriazoles
and benzodiazoles. Structures of preferred development inhibitor moieties
are:
##STR4##
where R.sub.29 is unsubstituted or substituted alkyl, especially alkyl
containing 1 to 32 carbon atoms, such as n-butyl, t-butyl, 1-ethylpentyl,
and 2-ethoxyethyl, or alkylthio, such as butylthio and octylthio;
unsubstituted or substituted aryl, such as phenyl; or a heterocyclic
group. R.sub.25 and R.sub.26 individually are hydrogen, alkyl of 1 to 8
carbon atoms such as methyl, ethyl, or butyl, phenyl or substituted
phenyl; and R.sub.27 and R.sub.28 individually are hydrogen or one or more
halogen such as chloro, fluoro or bromo; alkyl of 1 to 4 carbon atoms,
carboxyl, esters, such as --COOCH.sub.3, or other substituents such as
--NHCOOCH.sub.3, --SO.sub.2 OCH.sub.3, --OCH.sub.2 CH.sub.2 SO.sub.2
CH.sub.3,
##STR5##
or nitro groups.
Substituents on R.sub.29 include for example a halogen atom, a nitro group,
a cyano group, an aryl group, and alkoxy group, an aryloxy group, an
alkoxycarbonyl group, an aryloxycarbonyl group, a sulfamoyl group, a
sulfonamido group, a carbamoyl group, an alkylsulfo group, an aryl sulfo
group, a hydroxy group, an aryloxycarbonylamino group, an
alkoxycarbonylamino group, an acylamino group, a ureido group, an arylthio
group and an alkylthio group. When the R.sub.29 is an aryl group the aryl
group may be substituted as described for the alkyl group. When R.sub.29
is a heterocyclic group, the heterocyclic group is a 5- or 6-membered
monocyclic or condensed ring containing as a heteroatom a nitrogen atom,
an oxygen atom or a sulfur atom. Examples are a pyridyl group, a quinolyl
group, a furyl group, a benzothiazolyl group, an axazolyl group, an
imidazolyl group, a thiazolyl group, a traizllyl group, a benzotriazolyl
group, an imido group and an oxazine group.
B. PUG's which are, or form, dyes upon release:
Suitable dyes and dye precursors include azo, azomethine, azopyrazolone,
indoaniline, indophenol, anthraquinone, triarylmethane, alizarin, nitro,
quinoline, indigoid and phthalocyanine dyes or precursors of such dyes
such as leuco dyes, tetrazolium salts or shifted dyes. These dyes can be
metal complexed or metal complexable. Representative patents describing
such dyes are U.S. Pat. Nos. 3,880,658; 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 some preferred dyes and
dye precursors are:
______________________________________
##STR6## IIIB-1
##STR7## IIIB-2
##STR8## IIIB-3
##STR9## IIIB-4
R.sub.30
R.sub.31
______________________________________
##STR10##
Cl
##STR11##
Cl
##STR12##
______________________________________
C. PUG's which are couplers:
Couplers released can be nondiffusible color-forming couplers, non-color
forming couplers or diffusible competing couplers. Representative patents
and publications describing competing couplers are: "On the Chemistry of
White Couplers," by W. Puschel, Agfa-Gevaert AG Mitteilungen and der
Forschungs-Laboratorium der Agfa-Gevaert AG, Springer Verlag, 1954, pp.
352-367; U.S. Pat. Nos. 2,998,314; 2,808,329; 2,689,793; 2,742,832; German
Pat. No. 1,168,769 and British Pat. No. 907,274. Structures of preferred
competing couplers are:
##STR13##
where R.sub.32 is hydrogen or alkylcarbonyl, such as acetyl, and R.sub.33
and R.sub.34 are individually hydrogen or a solubilizing group, such as
sulfo, aminosulfonyl, and carboxy
##STR14##
where R.sub.35, which is the same as R.sub.34 as defined above, and
R.sub.36 is halogen, aryloxy, arylthio, or a development inhibitor, such
as a mercaptotetrazole, such as phenylmercaptotetrazole or
ethylmercaptotetrazole.
D. PUG's which form developing agents:
Developing agents released 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. Pat. Nos. 2,193,015; 2,108,243;
2,592,364; 3,656,950; 3,658,525; 2,751,297; 2,289,367; 2,772,282;
2,743,279; 2,753,256 and 2,304,953.
Structures of preferred developing agents are:
##STR15##
where R.sub.37 is hydrogen or alkyl of 1 to 4 carbon atoms and R.sub.38 is
hydrogen or one or more halogen such as chloro or bromo; or alkyl of 1 to
4 carbon atoms such as methyl, ethyl or butyl groups.
##STR16##
where R.sub.38 is as defined above.
##STR17##
where R.sub.39 is hydrogen or alkyl of 1 to 4 carbon atoms and R.sub.40,
R.sub.41, R.sub.42, R.sub.43 and R.sub.44 are individually hydrogen, alkyl
of 1 to 4 carbon atoms such as methyl or ethyl; hydroxyalkyl of 1 to 4
carbon atoms such as hydroxymethyl or hydroxyethyl or sulfoalkyl
containing 1 to 4 carbon atoms.
E. PUG's which are bleach inhibitors:
Representative patents are U.S. Pat. Nos. 3,705,801; 3,715,208; and German
OLS No. 2,405,279. Structures of preferred bleach inhibitors are:
##STR18##
where R.sub.45 is an alkyl group of 6 to 20 carbon atoms.
F. PUG's which are bleach accelerators:
##STR19##
wherein R.sub.46 is hydrogen, alkyl, such as ethyl and butyl, alkoxy, such
as ethoxy and butoxy, or alkylthio, such as ethylthio and butylthio, for
example containing 1 to 6 carbon atoms, and which may be unsubstituted or
substituted; R.sub.47 is hydrogen, alkyl or aryl, such as phenyl; R.sub.48
and R.sub.49 are individually alkyl, such as alkyl containing 1 to 6
carbon atoms, for example ethyl and butyl; z is 1 to 6.
The image dye-forming couplers can be incorporated in photographic elements
and/or in photographic processing 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
nondiffusible, that is they should be of such molecular size and
configuration that they will not significantly 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.
Photographic elements in which the compounds 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 compounds of this invention can be incorporated in at least
one of the silver halide emulsion layers and/or in at least one other
layer, such as an adjacent layer, where they will come into reactive
association with oxidized color developing agent which has developed
silver halide in the emulsion layer. The silver halide emulsion layer can
contain or have associated with it, other photographic coupler compounds,
such as dye-forming couplers, colored masking couplers, and/or competing
couplers. These other photographic couplers can form dyes of the same or
different color and hue as the photographic couplers of this invention.
Additionally, the silver halide emulsion layers and other layers of the
photographic element can contain addenda conventionally contained in such
layers.
A typical multilayer, multicolor photographic element can comprise 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 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.
The couplers of this invention can be incorporated in or associated with
one or more layers or units of the photographic element. For example, a
layer or unit affected by PUG can be controlled by incorporating in
appropriate locations in the element a scavenger layer which will confine
the action of PUG to the desired layer or unit. At least one of the layers
of the photographic element can be, for example, a mordant layer or a
barrier layer.
The light sensitive silver halide emulsions can include coarse, regular or
fine grain silver halide crystals or mixtures 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 silver halide grains. They can be chemically and
spectrally sensitized. The emulsions typically will be gelatin emulsions
although other hydrophilic colloids are useful. Tabular grain light
sensitive silver halides are particularly useful such as described in
Research Disclosure, January 1983, Item No. 22534 and U.S. Pat. No.
4,434,226.
The support can be any 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 .alpha.-olefin polymer, particularly a polymer of an
.alpha.-olefin containing 2 to 10 carbon atoms such as polyethylene,
polypropylene, ethylene-butene copolymers and the like.
It is preferred that the coupling-off group contain a releasable PUG.
Depending upon the nature of the particular PUG, the couplers can be
incorporated in a photographic element for different purposes and in
different locations.
In the following discussion of suitable materials for use in the emulsions
and elements of this invention, reference will be made to Research
Disclosure, December 1978, Item 17643, published by Industrial
Opportunities Ltd., Homewell Havant, Hampshire, PO9 1EF, U.K., the
disclosures of which are incorporated herein by reference. This
publication will be identified hereafter by the term "Research
Disclosure".
The photographic elements can be coated on a variety of supports as
described in Research Disclosure Section XVII and the references described
therein.
Photographic elements can be exposed to actinic radiation, typically in the
visible region of the spectrum, to form a latent image as described in
Research Disclosure Section XVIII and then processed to form a visible dye
image as described in Research Disclosure Section XIX. Processing to form
a visible dye image includes the step of contacting the element with a
color developing agent to reduce developable silver halide and oxidize the
color developing agent. Oxidized color developing agent in turn reacts
with the coupler to yield a dye.
Preferred color developing agents useful in the invention are p-phenylene
diamines. Especially preferred are 4-amino-N,N-diethylaniline
hydrochloride; 4-amino-3-methyl-N,N-diethylaniline hydrochloride;
4-amino-3-methyl-N-ethyl-N-.beta.-(methanesulfonamido)ethylaniline sulfate
hydrate; 4-amino-3-methyl-N-ethyl-N-.beta.-hydroxyethylaniline sulfate;
4-amino-3-.beta.-(methanesulfonamido)-ethyl-N,N-diethylaniline
hydrochloride; and 4-amino-N-ethyl-N-(2-methoxyethyl)-m-toluidine
di-p-toluenesulfonic acid.
With negative working silver halide. the processing step described above
gives a negative image. To obtain a positive (or reversal) image, this
step can be preceded by development with a non-chromogenic developing
agent to develop exposed silver halide, but not form a dye, and then
uniformly fogging the element to render unexposed silver halide
developable. Alternatively, a direct positive emulsion can be employed to
obtain a positive image.
Development is followed by the conventional steps of bleaching, fixing, or
bleach-fixing, to remove silver and silver halide, washing and drying.
Naphtholic couplers as described can be prepared by reactions and methods
known in the organic compound synthesis art. Similar reactions and methods
are described in U.S. Pat. No. 4,482,629. Typically, the naphtholic
coupler is prepared by the following method:
##STR20##
Ph herein means phenyl.
SYNTHESIS EXAMPLE A
Compound (A2)
Phenyl-1,4-dihydroxy-2-naphthoate (100.0 g, 356.78 mmol) was dissolved in
deoxygenated tetrahydrofuran (500 mL) and deoxygenated methanol (500 mL)
added. To this solution, stirred at room temperature under the nitrogen
atmosphere, was added ammonium acetate (50.0 g, 648.63 mmol) followed by
concentrated ammonium hydroxide (1.0 L). After stirring for 3 hours the
reaction was then poured into ice cold 2N-HCl (4.0 L) and enough
concentrated HCl added to bring the pH to 1. The resulting product,
compound (A2) was filtered off, washed well with water and air dried. The
crude product was washed with dichloromethane and air dried. Yield 62.0 g
(72%).
Compound (A3)
Compound (A2) (50.0 g, 0.246 mol) was dissolved in dry pyridine (150 mL)
and acetonitrile (75 mL) added. The solution was stirred and cooled to
-5.degree. to 0.degree. C. Ethyl chloroformate (50 mL, 0.523 mol) was then
added dropwise with stirring while maintaining the temperature at
0.degree. C. After the addition, the cooling bath was removed and the
temperature allowed to reach room temperature. The reaction mixture was
then gradually heated to reflux and the solvent allowed to distill off.
This procedure was continued until the temperature had risen to
approximately 120.degree. C. and 150 mL of solvent had been collected.
Heating under reflux was continued for an additional 1 hour period. The
reaction mixture was then cooled to approximately 50.degree. C. and poured
into 2N--HCl, (3.0 L) held at room temperature. This suspension was then
stirred for approximately 15 minutes, filtered and the residue washed well
with water, acetonitrile and finally ether. This gave the product,
compound (A3) sufficiently pure for the next step. Yield 43.5 g (77%).
Compound (A4)
Compound (A3) (23.0 g, 100.35 mmol) was taken up in deoxygenated
dimethylsulphoxide (250 mL) and deoxygenated water (25 mL) added. To this
solution, stirred at room temperature under nitrogen, was added
85%-potassium hydroxide (9.9 g, 150.53 mmol) and stirring continued until
dissolution, approximately 15 minutes. 4-Chloro-3-nitrobenzaldehyde (18.62
mmol) was then added all at once and the resulting solution stirred at
60.degree. C. for 1 hour. The reaction mixture was then poured into ice
cold 2N--HCl (2.0 L) and filtered off. The product, compound (A4), was
washed with water and, while still wet, slurried in methanol, filtered and
washed with ether. This product was pure enough to be used in the next
step. Yield 28.0 g (74%).
Compound (A5)
Compound (A4) (28.0 g, 74.01 mmol), in a powdered form, was suspended in
tetrahydrofuran (150 mL) and methanol (100 mL). Water (100 mL) was added
followed by sodium borohydride (2.8 g, 74.01 mmol) in small portions. More
tetrahydrofuran (50 mL) was added to aid stirring. At the end of the
sodium borohydride addition complete dissolution had been achieved. The
reaction was allowed to proceed for a further 15 minutes, then poured into
ice cold 2N--HCl (2.0 L) and the product filtered off. The product
compound (A5) was washed with methanol and while still wet with solvent,
suspended in ethanol and heated to reflux. The solution was cooled,
filtered, washed with methanol, ether and finally air dried. A second crop
of material was obtained on concentrating the mother liquor. Total yield
19.5 g (67%).
Compound (A6)
Compound (A5) (19.0 g, 50 mmol) was suspended in water (200 mL) containing
85%-potassium hydroxide (26.34 g, 400 mmol). To this mixture was added
methanol (50 mL) and then heated to 80.degree. C. for 1 hour. The
resulting dark yellow-brown solution was cooled and poured into ice cold
2N--HCl (2.0 L). The yellow product was filtered off, washed well with
water and air dried. Yield 17.7 g (100%).
Compound (A7)
Compound (A6) (17.7 g, 70 mmol) was dissolved in tetrahydrofuran (80 mL)
and methanol (300 mL) added. Raney-Nickel which had been washed several
times with water and then methanol was added and the solution hydrogenated
at 55 psi for 2 hours after which hydrogen up-take had ceased. The
catalyst was filtered off, washed with methanol and the filtrate
concentrated under reduced pressure to give the product, compound (A7).
This product was deemed sufficiently pure to be carried on to the next
step. Yield 100%.
Compound (A8)
Compound (A7) (50.0 mmol) was dissolved in dry pyridine (150 mL) and
hexadecylsulfonyl chloride (16.2 g, 50.0 mmol) added. The solution was
stirred at room temperature under a nitrogen atmosphere for 30 minutes.
The pyridine was concentrated under reduced pressure and the residue taken
up in ethyl acetate. This ethyl acetate solution was then washed with
2N--HCl (X3), dried (MgSO.sub.4), filtered and concentrated. The solvent
was removed under reduced pressure and the residual oil crystallized from
acetonitrile. After filtering, washing with acetonitrile and drying, the
yield of product compound (A8) amounted to 16.3 g (53% calculated from
compound (A5)).
Compound (A9)
Compound (A8) (16.3 g, 26.6 mmol) was dissolved in tetrahydrofuran (150 mL)
to which was added pyridine (3.2 mL, 39.90 mmol) followed by chloroacetic
anhydride (6.82 g, 39.89 mmol) in tetrahydrofuran (30 mL) at a reasonably
rapid rate. After stirring at room temperature for 30 minutes the solvent
was removed under reduced pressure and the residue dissolved in ethyl
acetate. The ethyl acetate solution was then washed with 2N--HCl (X2),
dried (MgSO.sub.4) and concentrated under reduced pressure. The residue
crystallized from acetonitrile to give compound (A9) 12.2 g (66%).
Compound (A10)
Compound (A9) (12.2 g, 17.7 mmol) was dissolved in dimethylformamide (150
mL) To which was added potassium iodide (4.4 g, 25.55 mmol) and aniline
(8.2 mL, 88.5 mmol) and the reaction mixture heated to 60.degree. C. for
1.5 hours. The reaction was poured into 2N--HCl and extracted with ethyl
acetate (X2). The combined ethyl acetate extracts were washed with 2N--HCl
(X3), dried (MgSO.sub.4), filtered and then concentrated. This residue was
used as such in the next step of the reaction sequence but it could be
crystallized from acetonitrile. Yield assumed to be 100%.
Compound (A11)
Compound (A10) (83.0 g, 111.26 mmol) was dissolved in tetrahydrofuran (800
mL) and the solution stirred at room temperature. N,N-4-diethylaniline
(17.7 mL, 111.26 mmol) was added followed by a solution of 12% phosgene in
toluene (275 mL, 333.78 mmol). The reaction mixture was stirred at room
temperature for 15 minutes, concentrated under reduced pressure and the
residue used as such in the next step. The yield of the product, compound
(A11), was assumed to be 100%.
Compound (A12)
Compound (A11) as described above (111.26 mmol) was dissolved in dry
pyridine (800 mL) and PMT (19.83 g, 111.26 mmol) added to the reaction
solution. The mixture was stirred at room temperature for 1 hour. It was
then concentrated under reduced pressure and the residue taken up in ethyl
acetate. The ethyl acetate was washed with 2N--HCl (X3), dried
(MgSO.sub.4), filtered and concentrated to an oil. The oil was taken up in
a mixture of ethyl acetate, dichloromethane, heptane and acetonitrile in
the ratio of 20:20:56.4, respectively and subjected to flash
chromatography eluting with the same solvent system to elute impurities
from the column and then changed to a ratio of 27:50:20.4 to elute the
product, compound (A12). The product could be recrystallized from
acetonitrile. Yield 61.0 g (58%).
Calculated for C.sub.50 H.sub.59 N.sub.7 O.sub.8 S.sub.2 : %C=63.20,
%H=6.26, %N=10.32, %S=6.75, Found: %C=63.14, %H=6.29, %N=10.23, %S=6.62.
Compound (A13)
Compound (A8) (4.0 g, 6.53 mmol) was suspended in dry ethe | | |
