Organic compounds -- part of the class 532-570 series – Organic compounds – Heterocyclic carbon compounds containing a hetero ring...
Reexamination Certificate
2001-06-22
2002-10-01
Lambkin, Deborah C. (Department: 1626)
Organic compounds -- part of the class 532-570 series
Organic compounds
Heterocyclic carbon compounds containing a hetero ring...
Reexamination Certificate
active
06458967
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates generally to the field of dyes useful in image recording.
DESCRIPTION OF RELATED ART
Kawamura et al. in U.S. Pat. No. 4,283,475 discloses a 2,6-di-t-butyl-4-[5-(2,6-di-t-butyl-4H-thiopyran-4-ylidene)penta-1,3-dienyl]thiopyrylium salts, and a process for production thereof. In particular, Kawamura et al. disclose 2,6-di-tert-butylthiopyrylium pentamethine hexafluorophosphate dye, as shown immediately below and identified as Compound (I), and variations of that dye. The variations alter the letter A from hydrogen to various other compounds disclosed in the '475 patent.
The thiopyrylium pentamethine dye of compound (I) has properties that make it a useful laser dye. For example, it has an absorption maximum of 822 nm in dichloromethane. This wavelength is compatible with gallium-arsenide diode lasers and other light sources emitting near 830 nm. Compound (I) also has an extinction coefficient in dichloromethane of 384,000 M
−1
cm
−1
at the absorption maximum and displays little crystallization in coated formats. These properties make compound (I) and variations thereof an ideal material for use as the heat-generating element in coated formats for thermal imaging, lithography, optical recording, and related imaging applications. Accordingly, compound (I) and its variations thereof are desired. The process to make these salts is set forth by Kawamura et al. In particular, Kawamura et al. disclose that the process is as follows: “Compound (i) [as shown immediately below] is heated in the presence of phosphorus pentasulfide at Step (1) . . . to obtain compound (ii). The reaction product, Compound (ii) is then reacted with alkali hydrosulfide such as potassium hydrosulfide in a solvent at a temperature between 50° C. to 200° C. in an atmosphere of an inert and oxygen-free gas such as N
2
, CO
2
, and argon gas (Step 2) to produce compound (iii). The solvent used at Step 2 is water-free and non aqueous solvent having at least 20 of dielectric constant and at least 2 of dipole moment, for example, hexamethyl phosphoric triamide, dimethylsulfoxide, N,N-dimethylformamide or N-methylpyrrolidone. The alkali sulfide or alkali hydrosulfide used is 1 to 30 moles, preferably 3 to 20 moles, per 1 mole of compound (ii). Compound (iii) is then reacted with an alkylating agent at Step 3 to obtain compound (iv) which is then hydrolyzed to form compound (v) [Step 4]. The reaction temperature at Step (3) is −10° C. to 200° C., preferably 40° C. to 100° C. and the reaction time is 30 minutes to 2 hours. In formula (iv), R
4
is an alkyl or substituted alkyl group derived from the alkylating agent. Compound (v) is subjected to the action of a Grignard reagent at a temperature of −20° C. to 25° C. for 30 to 90 minutes in a solvent and in a nonoxidizing atmosphere and then treated with an acid to form compound (II) (Step 5).”
Compound (II) is known as 2,6,-di-t-butyl-4-methylthiopyrylium salt. To obtain the desired 2,6-di-t-butyl-4-[5-(2,6-di-t-butyl-4H-thiopyran-4-ylidene)penta-1,3-dienyl]thiopyrylium salts and in particular 2,6-di-tert-butylthiopyrylium pentamethine hexafluorophosphate, compound (II) is reacted with a 1-phenylamino-3-phenylimino-1-propene, as shown immediately below and identified as compound (III), or a salt of the compound (III) with an acid.
The '457 patent disclosed that the “preferred examples of the compound of formula (III) are 1-phenylamino-3-phenylimino-1-propene, 2-benzyl-1-phenylamino-3-phenylimino-1-propene, 2-phenyl-1-phenylamino-3-phenylimino-1-propene, 2-bromo- or 2-chloro-1-phenylamino-3-phenylimino-1-propene, and 2-ethyl-1-phenylamino-3-phenylimino-1-propene.
The acid forming a salt with the compound (III) is an acid having a pKa generally not more than 4, preferably not more than 1, and includes, for example, hydrochloric acid, hydrobromic acid and sulfuric acid.
The reaction of compounds (II) and (III) is carried out either in a carboxylic acid anhydride or in an amine. When the reaction is carried out in the carboxylic acid anhydride, the carboxylic acid anhydride contributes to the reaction system as an aniline-eliminating agent. As a carboxylic acid anhydride an aliphatic carboxylic acid anhydride containing 4 to 16 carbon atoms and which may be substituted with one or more substituents, may be used. The substituents include halogen atoms, such as fluorine and chlorine. Specific examples of the carboxylic acid anhydride include acetic acid anhydride, propionic acid anhydride and trifluoro acetic acid anhydride. In order to dissolve the reaction materials, there may be added an auxiliary solvent which does not react with the raw materials, the carboxylic acid anhydride, the base described hereinafter and the reaction product in the reaction system, such as acetic acid or nitrobenzene. This reaction requires the presence of a base. The base is generally an organic base, for example alkali metal acetates such as sodium acetate or potassium acetate; alkylamines, preferably primary amines having 1 to 10 carbon atoms, secondary amines having 2 to 20 carbon atoms total or tertiary amines having 3 to 30 carbon atoms; aromatic amines; and nitrogen-containing aromatic amines. Specific examples are triethylamine, piperidine, aniline, dimethylaniline, pyridine, and quinoline.
The amount of the base used is 0.2 to 100 moles, preferably 0.5 to 20 moles, per mole of the 2,6-di-t-butyl-4-methylthiopyrylium salt. The weight ratio of the carboxylic acid anhydride to the 2,6-di-t-butyl-4-methylthiopyrylium salt is 0.1-100:1, preferably 1-50:1.
When the reaction is carried out in an amine, an auxiliary solvent such as acetic acid or nitro-benzene may likewise be added. The amine used in this reaction may be the same as those exemplified above as the base. The amount of amine is generally about 0.5 to 200 moles, preferably 1 to 100 moles per mole of the 2,6-di-t-butyl-4-methylthiopyrylium salt.
This process is generally carried out at about 50° to 200° C., preferably 80° to 140° C. The amounts of compounds (II) and (III) may be stoichiometric. Generally, about 0.3 to 1 mole of the 1-phenylamino-3-phenylimino-1-propene is used per mole of the 2,6-di-t-butyl-4-methylthiopyrylium salt. The reaction time varies depending upon the reaction temperature, the type of the solvent, etc., but is generally 1 minute to 1 hour.”
This process, however, is not economically viable because the overall yield of the critical compound (II) for the formation of compound (I) is below 30%, see synthesis example for compound (II) at columns 11 and 12 of the '475 patent. Accordingly, there is a need to make compound (II) at significantly higher overall yields to make compound (I) and variations thereof economically viable. This invention solves this problem.
SUMMARY OF THE INVENTION
The present invention provides a novel method for the synthesis of an intermediate dye product having the following formula:
wherein
L is S, Te, or Se;
R
1
and R
2
are either the same or different aryl or alkyl compounds;
R
3
is hydrogen or a short chain alkyl group; and
Z is an anion.
The process to formulate this intermediate compound entails reacting an R
1
-acetylene compound with an R
2
-acetylene compound (compounds A) into an enol ether compound with the R
1
and/or R
2
constituents (compound D). And from compound D, it forms into an intermediate dye compound having an L-based cyclic ring with the R
1
and/or R
2
constituents (compound F). With compound F the desired dye can be made with a greater overall yield for mass production.
DETAILED DESCRIPTION OF THE INVENTION
The present invention describes the synthesis of an intermediate dye compound (identified above as compound F) from an acetylene product (identified above as compound A). Compound F has the following formula:
wherein
L is S, Te, or Se;
R
1
and R
2
are either the same or different aryl or alkyl compounds;
R
3
is hydrogen or a short chain alkyl group; and
Z is an anion.
In particular, R
1
and R
2
are aryl, and/or lin
Detty Michael Ray
Virkler Peter Robert
Hudgson Russ LLP
The Research Foundation of State University of New York
LandOfFree
Method for preparation of an intermediate dye product does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for preparation of an intermediate dye product, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for preparation of an intermediate dye product will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2987564