Organic compounds -- part of the class 532-570 series – Organic compounds – Heterocyclic carbon compounds containing a hetero ring...
Reexamination Certificate
1999-04-20
2003-06-10
Stockton, Laura L. (Department: 1626)
Organic compounds -- part of the class 532-570 series
Organic compounds
Heterocyclic carbon compounds containing a hetero ring...
Reexamination Certificate
active
06576768
ABSTRACT:
The present invention relates to an improved process for preparing alkylthio- and/or arylthio-substituted diketo-diaryl-pyrrolopyrroles (DPPs) of the formula Ia and dithio-bridged bis-diketo-diaryl-pyrrolopyrroles (bis-DPPs) of the formula Ib
in which in formula Ia
G is phenyl substituted by at least one arylthio or alkylthio group, and
G
1
is G or a carbocyclic or heterocyclic radical, by reacting a haloaryl with a thiol or thiolate, and
in formula Ib
G
5
is a phenylene, G
6
is G
1
but not G, and G
7
is alkylene or phenylene, by reacting two haloaryls with a dithiol or dithiolate.
The invention additionally relates to novel, arylthio- or alkylthio-substituted DPPs, their use, and compositions comprising the DPPs of the invention.
U.S. Pat. No. 4,579,949 and U.S. Pat. No. 4,490,542 describe the preparation of DPPs substituted by at least one thioether group by reacting arylthio- or alkylthio-substituted benzonitriles with succinic esters. Disadvantages are the low yields in the case of long-chain alkylthio-DPPs and the impossibility of obtaining water-soluble compounds.
The reaction of DPP pigments with thiols to give alkylthio- or arylthio-substituted DPPs gives incomplete conversions owing to the poor solubility of these pigments.
Chemistry Letters 1978, 13-14 discloses that unactivated haloaryls can be substituted only in the presence of catalysts.
It was therefore an object of the invention to provide an improved process for preparing alkylthio- and/or arylthio-substituted DPPs which permits in particular the preparation of water-soluble compounds and long-chain alkylthio-DPPs. In particular, the process should be operable without high pressures and the use of catalysts. In addition, the economics of the process should be guaranteed by high yields. Furthermore, the invention was to provide novel, thioether-substituted diketo-diaryl-pyrrolopyrroles and also dithioether-bridged bis-DPPs which can be used in compositions with high molecular mass organic material, in particular as colorants. In addition, the thioether-substituted DPPs should be able to be used, in particular, as crystal growth inhibitors or rheology enhancers.
Accordingly, we have found the process defined at the outset, which involves reacting a thiol or thiolate with a halo-diketo-diaryl-pyrrolopyrrole (“halo-DPP”) of the formula IIa
in which G
2
is an unsubstituted or substituted, halogenated phenyl group and G
3
is G
2
or G
1
, or
reacting a dithiol or dithiolate with two halo-diketo-diaryl-pyrrolopyrroles (“halo-DPPs”) of the formula IIb
in which Hal is halogen such as fluorine, chlorine, bromine or iodine, preferably chlorine or bromine and, with particular preference, chlorine,
Hal being, in particular, in the para position of the phenylene.
Customarily, the reaction is started by bringing the thiol and/or thiolate or the dithiol and/or the dithiolate into contact with the halo-DPP IIa or IIb by conventional methods, for example by mixing the starting materials or by dropwise addition of one starting material to the other.
To prepare the compounds of the formula Ia the molar ratio of thiol to halo-DPP of the formula IIa is generally chosen to be within the range from 0.1:1 to 20:1, preferably in the range from 2:1 to 5:1 and, with particular preference, in the range from 2.1:1 to 2.7:1, and, to prepare the compounds of the formula Ib, the molar ratio of dithiol to halo-DPP of the formula IIb is generally chosen to be in the range from 0.5:1 to 20:1, preferably in the range from 0.5:1 to 5:1 and, with particular preference, in the range from 1:1 to 2.7:1.
Preferably, the reaction temperature is chosen to be within the range from 323 to 453 K, preferably in the range from 333 to 433 K, with particular preference in the range from 343 to 423 K and, with very particular preference, in the range from 343 to 413 K.
The reaction pressure is chosen to be generally within the range from 70 kPa to 10 MPa, preferably from 90 kPa to 5 MPa; atmospheric pressure is particularly preferred.
The reaction time depends generally on the reactivity of the starting materials, the chosen reaction temperature and the desired conversion. The reaction time is customarily chosen to be within the range from 15 minutes to 2 days.
In one preferred embodiment the reaction is conducted under an inert gas atmosphere using for this purpose preferably nitrogen or noble gases such as helium or argon. Particular preference is given to reaction in a nitrogen atmosphere.
In addition, the reaction can be carried out with or without solvent, with preference being given to reaction in a solvent. Preferred solvents are organic solvents or solvent mixtures such as aprotic, especially non-aqueous aprotic, solvents. Aprotic solvents may be apolar, such as benzene, chlorobenzene and chlorinated hydrocarbons, or polar. The latter are particularly preferred. Examples of polar aprotic solvents which can be used are amides such as hexamethyl-phosphoramide, carboxamides such as N,N′-dimethylformamide and N,N′-dimethylacetamide, or lactams such as N-methylpyrrolidone, N-methyl-2-piperidone, 1,3-dimethyl-3,4,5,6-tetrahydro-3(1H)pyrimidinone or N-methyl-4-piperidone, or urea bases such as N,N′-dimethylethyleneurea, N,N′-dimethyl propyleneurea, and also acetonitrile, sulfolane, dimethyl sulfoxide, or aromatic solvents such as nitrobenzene.
Preference is given to N,N′-dimethylformamide, N,N′-dimethylacetamide, dimethyl sulfoxide, 1,3-dimethyl-3,4,5,6-tetrahydro-3(1H)pyrimidinone or N-methyl-pyrrolidone.
The weight ratio of halo-DPP IIa or halo-DPP IIb to the solvent lies in general within the range from 0.5 to 10% by weight, with particular preference in the range from 1 to 5% by weight and, with very particular preference, in the range from 2 to 3% by weight.
In another preferred embodiment the reaction is conducted in the presence of a base. Examples of suitable bases are alkali metal carbonates, for example Na
2
CO
3
or K
2
CO
3
, alkali metal hydrogencarbonates, for example NaHCO
3
or KHCO
3
, alkali metal hydroxides, for example NaOH or KOH, alkali metals, such as sodium or potassium, and also aromatic bases, such as pyridine, N,N′-dimethylaminopyridine or quinoline. Preference is given to non-aqueous alkali metal bases and to aromatic bases, particular preference to non-aqueous alkali metal carbonates or alkali metal hydrogencarbonates, and very particular preference to anhydrous K
2
CO
3
.
The molar ratio of base to thiol or thiolate lies customarily within the range from 0.5:1 to 5:1, preferably in the range from 1:1 to 4:1 and, with particular preference, in the range from 1:1 to 3:1, and the molar ratio of base to dithiol or dithiolate lies customarily within the range from 1:1 to 10:1, preferably within the range from 1:1 to 5:1 and, with particular preference, in the range from 1:1 to 4:1.
In a preferred embodiment of the process of the invention the reaction is conducted in the presence of a solvent or solvent mixture and a base.
If desired, the reaction can also be conducted in the presence of catalysts, especially transition metal catalysts, examples being tetrakis(triphenyl-phosphine)palladium(0), -nickel(0), and -platinum(0), and -ruthenium(II) chloride. Preferably, the reaction is conducted without a catalyst.
If a catalyst is used, it is generally employed in a proportion within the range from 0.001 to 10% by weight, based on halo-DPP of the formula IIa or IIb, and preferably from 0.5 to 7% by weight and, with particular preference, from 2 to 5% by weight based on the total amount of reactants.
The reaction mixture can be worked up by conventional methods, for example by filtration and subsequent washing of the filter residue and subsequent optional drying. The product may be an individual compound or a mixture of differently substituted compounds of the formula Ia, or a mixture consisting of halo-DPP IIa and a compound of the formula Ia, or else a mixture consisting of halo-DPP IIb and a compound of the formula Ib and/or Ia.
In accordance with observations made to date the thiol or th
Hao Zhimin
Rochat Alain Claude
Schlöder-Tebaldi Nancy
Ciba Specialty Chemicals Corporation
Crichton David R.
Stockton Laura L.
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