U.S. patent application number 10/702897 was filed with the patent office on 2004-06-10 for synthesis of certain triazole compounds.
Invention is credited to Harder, John W., Place, Ileana, Romanet, Robert F., Vreeland, William B..
Application Number | 20040110962 10/702897 |
Document ID | / |
Family ID | 29549822 |
Filed Date | 2004-06-10 |
United States Patent
Application |
20040110962 |
Kind Code |
A1 |
Place, Ileana ; et
al. |
June 10, 2004 |
Synthesis of certain triazole compounds
Abstract
Disclosed is a process for forming a 1H-pyrazolo
(1,5-b)-[1,2,4]-triazole compound by ring closing a pyrazoloamidine
compound comprising reacting the amidine with an oxidizing agent
having a reduction potential vs Ag/AgCl that is more positive than
-0.16V and less than +1.43V in the presence of a halogen atom. The
invention also discloses certain triazole compounds that are
successfully made by the conventional process. The process and
compounds of the invention provide improved yields and reduce or
eliminate unwanted side-reactions.
Inventors: |
Place, Ileana; (Webster,
NY) ; Harder, John W.; (Rochester, NY) ;
Romanet, Robert F.; (Rochester, NY) ; Vreeland,
William B.; (Webster, NY) |
Correspondence
Address: |
Paul A. Leipold
Patent Legal Staff
Eastman Kodak Company
343 State Street
Rochester
NY
14650-2201
US
|
Family ID: |
29549822 |
Appl. No.: |
10/702897 |
Filed: |
November 6, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10702897 |
Nov 6, 2003 |
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10315631 |
Dec 10, 2002 |
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6657066 |
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Current U.S.
Class: |
548/262.4 |
Current CPC
Class: |
C07D 487/04
20130101 |
Class at
Publication: |
548/262.4 |
International
Class: |
C07D 487/04 |
Claims
What is claimed is:
1. A process for forming a 1H-pyrazolo (1,5-b)-[1,2,4]-triazole
compound by ring closing a pyrazoloamidine compound comprising
reacting the amidine with an oxidizing agent having a reduction
potential vs Ag/AgCl that is more positive than -0.1 6V and less
than +1.43V in the presence of a halogen atom.
2. The process of claim 1 wherein the halogen is a part of the
oxidizing agent.
3. The process of claim 1 wherein the halogen is part of a separate
compound from the oxidizing agent.
4. The process of claim 1 wherein the reduction potential is less
than 1.3.
5. The process of claim 1 wherein the reduction potential is more
positive than 0.
6. The process of claim 1 wherein the reduction potential from 0 to
1.1.
7. The process of claim 1 wherein the reduction potential is from
0.1 to 1.0.
8. The process of claim 1 wherein the oxidizing agent is selected
from the group consisting of halogens, chloro, bromo, iodo or
imides, hypervalent iodine compounds, perhalogen compounds,
peroxide/halide combinations, sulfonyl halides, halo-hydantoins and
N-halo compounds.
9. The process of claim 1 wherein the oxidizing agent is selected
from the following: 8910
10. The process of claim 1 wherein the oxidation reaction is
carried out at a temperature of from 15 to 150.degree. C.
11. The process of claim 10 wherein the oxidation reaction is
carried out at a temperature of from 60 to 100.degree. C.
12. The process of claim 1 wherein the reaction is performed in an
aprotic solvent.
13. The process of claim 12 wherein the solvent is selected from
the group consisting of aprotic solvents that are basic.
14. The process of claim 12 wherein the aprotic solvent is selected
from the group consisting of dimethyl formamide, dimethyl
acetamide, pyridine, butyronitrile, chlorobenzene,
1,2-dichloroethane, toluene, acetic acid, dioxane, and ethylene
glycol dimethyl ether.
15. A process for forming a 1H-pyrazolo (1,5-b)-[1,2,4]-triazole
compound by ring closing a pyrazoloamidine as shown in the
following equation: 11wherein, R.sup.1 and R.sup.2 are
independently selected alkyl or aryl groups; Z is H or a
substituent; and OA/HAL represents an oxidizing agent that contains
a halogen or a combination of an oxidizing agent and a halogen
containing compound, the oxidizing agent having a reduction
potential vs Ag/AgCl that is more positive than -0.1 6V and less
than +1.43V.
16. The process of claim 15 wherein Z is Cl.
17. The process of claim 15 wherein R.sup.1 is a tertiary carbon
atom.
18. The process of claim 15 wherein R.sup.1 is a t-butyl group.
19. The process of claim 15 wherein R.sup.2 is a substituted alkyl
or aryl group containing at least 8 carbon atoms.
20. The process of claim 15 wherein the reduction potential is in
the range of from 0 to 1.0.
21. The process of claim 15 wherein the oxidizing agent is selected
from the group consisting of halogens, chloroamides or imides,
hypervalent iodine compounds, perhalogen compounds, peroxide/halide
combinations, sulfonyl halides, halo-hydantoins and N-halo
compounds.
22. The process of claim 15 wherein the reaction is performed in an
aprotic solvent.
23. A 1H-pyrazolo (1,5-b)-[1,2,4]-triazole compound containing an
anionic leaving group .gamma. to the 2-position of the
triazole.
24. The compound of claim 23 wherein the anionic leaving group is
selected from --SR, --OR, and --SO.sub.2OR, where R is a
substituent.
25. The compound of claim 23 containing at least one alkyl
substituent on the .alpha. carbon.
26. The compound of claim 24 containing at least one alkyl
substituent on the .alpha. carbon.
Description
FIELD OF THE INVENTION
[0001] This invention relates to pyrazolotriazole compounds and a
process for preparing them employing certain oxidant/halogen
containing materials.
BACKGROUND OF THE INVENTION
[0002] One of the useful classes of dyes is one based on a
1H-pyrazolo (1,5-b)-[1,2,4]-triazole compound. These dyes are
desirable because they have a spectral absorption curve that has a
relatively narrow half-bandwidth and because they can typically be
stabilized to provide a very useful half-life. Such dyes of the
aza-methine type typically have a hue in the 500-600 nm range
although with judicious selection of the substituents it is
possible to shift the maximum absorption outside that range.
[0003] One notable use for such dyes is in photographic imaging,
particularly silver halide imaging. In such imaging, 1H-pyrazolo
(1,5-b)-[1,2,4]-triazole coupler compounds having a leaving group
are imagewise converted to the desired dye by a coupling reaction
with an oxidized developer, typically a p-phenylene diamine, to
form the corresponding dye. The use of such couplers and dyes is
detailed In U.S. Pat. Nos. 4,540,654 and 4,621,046.
[0004] While such couplers have been found advantageous, the
methods of synthesizing them could be improved on. One scheme
disclosed for preparing the described triazole couplers is set
forth in U.S. Pat. No. 5,378,587. It includes oxamination of the
corresponding amidine to form the oxime, sulfonating to form the
sulfonate, and heating to ring close and form the desired
pyrazolotriazole. Although, this reaction is effective, it requires
3 steps to arrive at the desired product from the amidine.
[0005] One method for accomplishing the desired conversion is
taught in EP 119,860. This method employs direct oxidation of the
imidate to the desired triazole using a lead tetra-acetate as an
oxidizing agent. When this method was employed in Synthesis Example
11, the reaction provided a yield of only 5.7%. Yields this low are
not usually of commercial significance. Higher yields of at least
15% and more desirably at least 40 or even 70% are desired. Yield
is important especially when a sequence of reactions is employed,
each of which has a yield factor, the combination of which can make
the overall yield excessively low.
[0006] It is a problem to be solved to provide an alternative means
for preparing a 1H-pyrazolo (1,5-b)-[1,2,4]-triazole compound from
the corresponding imidate which can be accomplished with less than
three steps and results in desirably high yields.
SUMMARY OF THE INVENTION
[0007] The invention provides a process for forming a 1H-pyrazolo
(1,5-b)-[1,2,4]-triazole compound by ring closing a pyrazoloamidine
compound comprising reacting the amidine with an oxidizing agent
having a reduction potential vs Ag/AgCl that is more positive than
-0.16V and less than +1.43V in the presence of a halogen atom. The
invention also provides certain triazole compounds that are not
successfully made by the conventional process.
[0008] The process and compound of the invention provide improved
yields and reduce or eliminate unwanted side-reactions.
DETAILED DESCRIPTION OF THE INVENTION
[0009] The invention is summarized above.
[0010] The halogen employed in the reaction may either be part of
the oxidizing agent or part of a separate compound from the
oxidizing agent. The reduction potential vs. Ag/AgCl is more
positive than -0.16 and less than +1.43 and is desirably more
positive than 0 and less than 1.3. Suitably, the range of
potentials is from 0 to 1.1, and typically from 0.1 to 1.0. The
reduction potential is measured in the conventional manner vs.
Ag/AgCl.
[0011] The oxidizing agent is selected from any of those that
provide the desired reduction potential. Suitable ones include
those selected from the group consisting of halogens, chloro,
bromo, or iodoamides, chloro, bromo or iodoimides, hypervalent
iodine compounds, perhalogen compounds, peroxide/halide
combinations, sulfonyl halides, halo-hydantoins and N-halo
compounds.
[0012] Examples of halogen containing oxidants and their
corresponding redox potentials are as shown in Table I:
1TABLE I Oxidant Redox Potential Ref. Electrode Type DCDMH** -0.2 V
" Comparative N,N-dichloro- dimethylhydantoin NCS*** -0.16 V " "
N-chlorosuccinimide Lead Tetraacetate* 1.43 V Ag/AgCl "
Iodobenzene-bis- 0.06 to 1.0 V " Invention trifluoroacetate*.sup..-
sctn. Iodobenzene 0.06 to 1.0 V " " diacetate*.sup..sctn.
Hydroxytosyloxy- 0.06 to 1.0 V " " iodobenzene*.sup..sctn. DBDMH**
0.4 V " " N,N-dibromo- dimethylhydantoin Br.sub.2* 0.88 V " "
Cl.sub.2* 1.16 V " "
*http://library.thinkquest.org/3659/reference/reductionpotentials.html?tq-
skip 1 = 1 &tqtime = 0710 **US5,972,864 ***Lind, J.; Jonsson,
M.; Erikson, T. E., Merenyi, G. J. Phys. Chem., 1993, 97, 1610-1614
.sctn. - The range of +0.06 to 1.0 V is estimated taking into
consideration the data of iodine oxidation given in the
reference*
[0013] Specific examples of oxidizing agent/halogen combinations
useful in the invention are: 123
[0014] The inventive process for forming a 1H-pyrazolo
(1,5-b)-[1,2,4]-triazole compound by ring closing a pyrazoloamidine
is shown in the following equation: 4
[0015] wherein,
[0016] R.sup.1 and R.sup.2 are independently selected alkyl or aryl
groups;
[0017] Z is H or a substituent; and
[0018] OA/HAL represents an oxidizing agent that contains a halogen
or a combination of an oxidizing agent and a halogen containing
compound, the oxidizing agent having a reduction potential vs
Ag/AgCl that is more positive than -0.2V and less than +1.7V.
[0019] Z is conveniently Cl. R.sup.1 is desirably a tertiary carbon
atom such as a t-butyl group. R.sup.2 is suitably a substituted
alkyl or aryl group containing at least 8 carbon atoms.
[0020] The oxidation reaction is suitably carried out at a
temperature of from 15 to 150.degree. C., and usually at a
temperature of from 60 to 100.degree. C. The reactants are
desirably brought together in an aprotic solvent such as an aprotic
solvent that is basic, such as one selected from the group
consisting of dimethyl formamide, dimethyl acetamide, pyridine,
butyronitrile, chlorobenzene, nitrobenzene, 1,2-dichloroethane,
toluene, acetic acid, dioxane, ethylene glycol dimethyl ether, and
N-methylpyrrolidone.
[0021] It is observed that the oxidation step transforms the
amidine to the pyrazolotriazole coupler in one step compared to the
three steps in the prior art process. As will be shown in the
examples that follow, it will provide superior yields of the
desired product. Further, it enables the production of triazole
compounds that could not be successfully made by the oxime route
since the inventive route serves to reduce or eliminate undesired
side-reactions.
[0022] Compounds that may be made by the process of the invention
but not by the conventional process of oxamination are 1H-pyrazolo
(1,5-b)-[1,2,4]-triazole compounds containing an anionic leaving
group .gamma. to the 2-position of the triazole. Examples of such
groups are --Cl, --Br, --I, --OR, and --SO.sub.2OR, where R is a
substituent, particularly those compounds where at least one alkyl
substituent on the .alpha. carbon.
[0023] Unless otherwise specifically stated, use of the term
"group", "substituted" or "substituent" means any group or radical
other than hydrogen. Additionally, when reference is made in this
application to a compound or group that contains a substitutable
hydrogen, it is also intended to encompass not only the
unsubstituted form, but also its form further substituted with any
substituent group or groups as herein mentioned, so long as the
substituent does not destroy properties necessary for the intended
utility. Suitably, a substituent group may be halogen or may be
bonded to the remainder of the molecule by an atom of carbon,
silicon, oxygen, nitrogen, phosphorous, or sulfur. The substituent
may be, for example, halogen, such as chloro, bromo or fluoro;
nitro; hydroxyl; cyano; carboxyl; or groups which may be further
substituted, such as alkyl, including straight or branched chain or
cyclic alkyl, such as methyl, trifluoromethyl, ethyl, t-butyl,
3-(2,4-di-t-pentylphenoxy) propyl, cyclohexyl, and tetradecyl;
alkenyl, such as ethylene, 2-butene; alkoxy, such as methoxy,
ethoxy, propoxy, butoxy, 2-methoxyethoxy, sec-butoxy, hexyloxy,
2-ethylhexyloxy, tetradecyloxy, 2-(2,4-di-t-pentylphenoxy)ethoxy,
and 2-dodecyloxyethoxy; aryl such as phenyl, 4-t-butylphenyl,
2,4,6-trimethylphenyl, naphthyl; aryloxy, such as phenoxy,
2-methylphenoxy, alpha- or beta-naphthyloxy, and 4-tolyloxy;
carbonamido, such as acetamido, benzamido, butyramido,
tetradecanamido, alpha-(2,4-di-t-pentyl-phenoxy)acetamido,
alpha-(2,4-di-t-pentylphenoxy)butyramido,
alpha-(3-pentadecylphenoxy)-hex- anamido,
alpha-(4-hydroxy-3-t-butylphenoxy)-tetradecanamido,
2-oxo-pyrrolidin-1-yl, 2-oxo-5-tetradecylpyrrolin-1-yl,
N-methyltetradecanamido, N-succinimido, N-phthalimido,
2,5-dioxo-1-oxazolidinyl, 3-dodecyl-2,5-dioxo-1-imidazolyl, and
N-acetyl-N-dodecylamino, ethoxycarbonylamino, phenoxycarbonylamino,
benzyloxycarbonylamino, hexadecyloxycarbonylamino,
2,4-di-t-butylphenoxycarbonylamino, phenylcarbonylamino,
2,5-(di-t-pentylphenyl)carbonyl amino,
p-dodecylphenylcarbonylamino, p-tolylcarbonylamino, N-methylureido,
N,N-dimethylureido, N-methyl-N-dodecylureido, N-hexadecylureido,
N,N-dioctadecylureido, N,N-dioctyl-N'-ethylureido, N-phenylureido,
N,N-diphenylureido, N-phenyl-N-p-tolylureido,
N-(m-hexadecylphenyl)ureido,
N,N-(2,5-di-t-pentylphenyl)-N'-ethylureido, and t-butylcarbonamido;
sulfonamido, such as methylsulfonamido, benzenesulfonamido,
p-tolylsulfonamido, p-dodecylbenzenesulfonamido,
N-methyltetradecylsulfon- amido, N,N-dipropylsulfamoylamino, and
hexadecylsulfonamido; sulfamoyl, such as N-methylsulfamoyl,
N-ethylsulfamoyl, N,N-dipropylsulfamoyl, N-hexadecylsulfamoyl,
N,N-dimethylsulfamoyl; N-[3-(dodecyloxy)propyl]sulf- amoyl,
N-[4-(2,4-di-t-pentylphenoxy)butyl]sulfamoyl,
N-methyl-N-tetradecylsulfamoyl, and N-dodecylsulfamoyl; carbamoyl,
such as N-methylcarbamoyl, N,N-dibutylcarbamoyl,
N-octadecylcarbamoyl, N-[4-(2,4-di-t-pentylphenoxy)butyl]carbamoyl,
N-methyl-N-tetradecylcarbam- oyl, and N,N-dioctylcarbamoyl; acyl,
such as acetyl, (2,4-di-t-amylphenoxy)acetyl, phenoxycarbonyl,
p-dodecyloxyphenoxycarbony- l methoxycarbonyl, butoxycarbonyl,
tetradecyloxycarbonyl, ethoxycarbonyl, benzyloxycarbonyl,
3-pentadecyloxycarbonyl, and dodecyloxycarbonyl; sulfonyl, such as
methoxysulfonyl, octyloxysulfonyl, tetradecyloxysulfonyl,
2-ethylbexyloxysulfonyl, phenoxysulfonyl,
2,4-di-t-pentylphenoxysulfonyl, methylsulfonyl, octylsulfonyl,
2-ethylhexylsulfonyl, dodecylsulfonyl, hexadecylsulfonyl,
phenylsulfonyl, 4-nonylphenylsulfonyl, and p-tolylsulfonyl;
sulfonyloxy, such as dodecylsulfonyloxy, and hexadecylsulfonyloxy;
sulfinyl, such as methylsulfinyl, octylsulfinyl,
2-ethylhexylsulfinyl, dodecylsulfinyl, hexadecylsulfinyl,
phenylsulfinyl, 4-nonylphenylsulfinyl, and p-tolylsulfinyl; thio,
such as ethylthio, octylthio, benzylthio, tetradecylthio,
2-(2,4-di-t-pentylphenoxy)ethylthio, phenylthio,
2-butoxy-5-t-octylpbenylthio, and p-tolylthio; acyloxy, such as
acetyloxy, benzoyloxy, octadecanoyloxy, p-dodecylamidobenzoyloxy,
N-phenylcarbamoyloxy, N-ethylcarbamoyloxy, and
cyclohexylcarbonyloxy; amine, such as phenylanilino,
2-chloroanilino, diethylamine, dodecylamine; imino, such as 1
(N-phenylimido)ethyl, N-succinimido or 3-benzylhydantoinyl;
phosphate, such as dimethylphosphate and ethylbutylphosphate;
phosphite, such as diethyl and dihexylphosphite; a heterocyclic
group, a heterocyclic oxy group or a heterocyclic thio group, each
of which may be substituted and which contain a 3 to 7 membered
heterocyclic ring composed of carbon atoms and at least one hetero
atom selected from the group consisting of oxygen, nitrogen and
sulfur, such as 2-furyl, 2-thienyl, 2-benzimidazolyloxy or
2-benzothiazolyl; quaternary ammonium, such as triethylammonium;
and silyloxy, such as trimethylsilyloxy.
[0024] If desired, the substituents may themselves be further
substituted one or more times with the described substituent
groups. The particular substituents used may be selected by those
skilled in the art to attain the desired desirable properties for a
specific application and can include, for example, hydrophobic
groups, solubilizing groups, blocking groups, and releasing or
releasable groups. When a molecule may have two or more
substituents, the substituents may be joined together to form a
ring such as a fused ring unless otherwise provided.
[0025] The compounds synthesized in accordance with the invention
are useful as coupler intermediates for the formation of dyes such
as in the coloring and imaging arts.
[0026] The entire contents of the patents and other publications
referred to in this specification are incorporated herein by
reference.
EXAMPLES
Example 1
[0027] The process of the invention is carried out as follows:
5
[0028] 10 g (0.0257 moles) of amidine were dissolved in 50 ml
dimethyl formamide and stirred it at room temperature, while adding
33.19 g (0.103 moles) of iodobenzene diacetate (reduction potential
about 0.6V) to the reaction mixture. The reaction mixture was
heated at 80.degree. C. for 8 hours until the reaction was
complete. Work up of the reaction mixture was accomplished by
drowning it in water, extracting it in ethyl acetate, drying the
ethyl acetate layer over magnesium sulfate, and then using the
rotatory evaporator to remove the solvent. The crude product was
purified by column chromatography on silica gel using a gradient of
30-50% ethyl acetate to heptane. 5.5 g (55% yield) of pure product
was obtained after chromatography.
Example 2
[0029] The same compound is alternatively prepared in accordance
with the invention as follows: 6
[0030] 7.8 g (0.02 moles) of amidine was dissolved in 50 ml
dimethyl formamide and stirred at room temperature, while adding
6.4 g (0.04 moles) of liquid bromine (reduction potential 0.88V) to
the reaction mixture. The reaction mixture was heated at 80.degree.
C. for 40 minutes, when reaction was complete. The product was
worked up by drowning it in water and extracting it in ethyl
acetate, drying the ethyl acetate layer over magnesium sulfate and
then using the rotatory evaporator to remove the solvent. The crude
product was purified by column chromatography on silica gel using a
gradient of 10-40% ethyl acetate to heptane to obtain 6.0 g (77%
yield) of pure product after chromatography.
Example 3
[0031] A further inventive alternative is carried out as follows:
7
[0032] 7.8 g (0.02 moles) of amidine were dissolved in 50 ml
dimethyl formamide and stirred it at room temperature, while adding
5.7 g (0.02 moles) of 1,3-dibromo 5,5-dimethylhydantoin (reduction
potential of 0.4V) to the reaction mixture. The reaction mixture
was heated at 80.degree. C. for 60 minutes, when reaction was
complete. The reaction mixture was worked up by drowning it in
water and extracting it in ethyl acetate, drying the ethyl acetate
layer over magnesium sulfate and then using the rotatory evaporator
to remove the solvent. The crude product was purified by column
chromatography on silica gel using a gradient of 30-50% ethyl
acetate to heptane. 3.3 g (42% yield) of pure product were obtained
after chromatography.
Example 4
[0033] Several experiments with different oxidizing agents for this
ring closure were set-up in parallel overnight. The amidine was
that used for Example 3, above and the reaction was conducted at
80.degree. C. The other reagents and the results are as summarized
in Table II.
2TABLE II Sample Type Oxidizing Agent Solvent Yield-wt % 1
Invention iodobenzenediacetate DMF 55 2 Invention Br.sub.2 " 77 3
Invention N,N-dibromo- " 42 dimethylhydantoin 4 Comp SOCl.sub.2 "
No product 5 Invention SO.sub.2Cl.sub.2 " 17 6 Invention
(CF.sub.3COO).sub.2IC.sub.6H.sub.5 " 64 7 Invention
hydroxytosyloxy- " 30 iodoC.sub.6H.sub.5 8 Comp Lead Tetraacetate "
12 9 Comp FeCl.sub.3.6H.sub.2O MeOH No product 10 Comp FeCl.sub.3 "
No product
[0034] As the table shows, desirable yields above 15 wt % were
obtained with halogen containing oxidizing agents having a redox
potential above.
[0035] The entire contents of the patents and other publications
referred to in this specification are incorporated herein by
reference.
* * * * *
References