Organic compounds -- part of the class 532-570 series – Organic compounds – Chalcogen in the nitrogen containing substituent
Reexamination Certificate
2000-03-15
2002-10-29
Shah, Mukund J. (Department: 1624)
Organic compounds -- part of the class 532-570 series
Organic compounds
Chalcogen in the nitrogen containing substituent
Reexamination Certificate
active
06472527
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates to a new process of forming heterocyclic compounds and their use in the preparation of asymmetrical cis- or trans-thiazine-indigo compounds. This invention also relates to a new process of forming new cis- or trans-thiazine-indigo compounds containing further heterocyclic or carbonamido moieties. This invention also relates to a process of converting the cis-thiazine-indigo compounds into the trans-thiazine-indigo isomers, which are known to be pigments.
Thiazine-indigo compounds are an important series of pigments. Prior art processes for forming these pigments involve the reaction of certain o-aminomercapto-carbocyclic or -heterocyclic compounds with maleic acid or a derivative thereof in the presence of a solvent. Solvents useful for this purpose were either a carboxylic acid (which also acted to catalyze the reaction) or an inert polar aprotic solvent.
Thus, in DE 2 151 723 a process is described for making symmetrically substituted benzothiazine-indigo compounds wherein substituted ortho-aminomercapto-carbocyclic or -heterocyclic compounds are reacted with a maleic acid derivative in a carboxylic acid, e.g. acetic acid. By symmetrically substituted is meant that there is identical substitution on each of the benzothiazine rings.
In DE-OS 253 61 20 a process is described for making other symmetrically substituted benzothiazine-indigo compounds wherein substituted ortho-aminothiophenols are reacted with a maleic acid derivative in an inert polar aprotic solvent. It is alleged that the benzothiazine-indigo compounds so formed display improved pigmentary properties, e.g. brighter and cleaner shade over the compounds made in a carboxylic acid solution. However, they can only be produced in poor yield.
An improved process of forming thiazine-indigo pigments is also described in the international application WO 98/32800 A1.
There still remains a need to provide a further improved process of forming thiazine-indigo compounds, especially trans-thiazine-indigo pigments.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Accordingly, the invention provides in one of its aspects an environmentally friendly water-based process for the preparation of thiazine-indigo compounds according to the formula (I) and (II)
wherein R
1
and R
2
independently represent the atoms necessary to complete the formation of a substituted or unsubstituted aromatic or aliphatic carbocyclic or heterocyclic ring system and R
3
is hydrogen, C
1-12
alkyl or phenyl, comprising the step of reacting in the presence of an aqueous system a compound of formula (Ia) resp. (Ib)
with a compound of formula (IIa)
in which formulae R
1
, R
2
and R
3
have the meaning indicated above; Hal is Cl or Br; R
4
is hydrogen or a metallic ion selected from Na
+
, K
+
or Zn
2+
and R
5
is a leaving group commonly used in substitution reactions at carbonyl carbon atoms.
The aqueous system comprises water or water and an acidic catalyst or water and a basic catalyst or a mixture of water and a with water miscible solvent, like alcohols.
Preferably the molar ratio of the reactants is 1:1.
The process is carried out in the presence of a carboxylic acid or of a salt thereof, e.g. acetic acid, or an inorganic acid or salt thereof, e.g. sulphuric acid or hydrochloric acid, which also acts as a catalyst, and an aqueous medium, e.g. water or a mixture of water and a miscible solvent, preferably an alcohol with 1-5 C-atoms, e.g. ethanol, methanol, butanol or another high boiling point alcohol.
The basic catalyst is an inorganic base, especially sodium or potassium hydroxide or an organic base such as triethylamine.
The reaction is preferably carried out in water in the presence of 0 to 95% by weight, preferably 10% by weight of an acid catalyst, e.g. acetic acid or hydrochloric acid or sulphuric acid or phosphoric acid.
The reaction temperature is preferably of the order of 0 to 150° C., more preferably between 10 and 40° C.
The leaving group in R
5
is either hydroxy, chlorine or a C
1-5
alkoxy group.
A further aspect of the invention consists in the process for the preparation of partly new compounds of the formula (Ia) and (Ib)
wherein the substituents R
1
, R
2
, R
3
, R
5
and Hal have the meaning given above, comprising the reaction of a compound of formula (IIb)
with a compound of formula (IIIa) or (IIIb)
wherein Hal is Cl or Br and R
5
is a leaving group commonly used in substitution reactions at carbonyl carbon atoms,
in the same aqueous system as described above.
Compounds of formula (II), (IIIa) and (IIIb) are known compounds or can be prepared in analogy to known methods.
The compound of formula (IV)
is known and its preparation is described in Aust. J. Chem., 39, 503-510 (1986). However, the reaction is performed in organic solvents and the product was isolated in poor yield (28.8%) as a by-product.
The preparation of compound (IV) is also described in Helvetica Chem. Acta, 57 (8), 2664-78 (1974). Herein the reaction is carried out in glacial acetic acid.
The water based process of the invention is generally applicable and allows the preparation of other derivatives, in good yield.
The thiazine-indigo compounds of formula (I) or (II) may be symmetrically substituted, that is R
1
and R
2
are identical. Alternatively, they may be asymmetrically substituted, that is R
1
and R
2
are not identical. Non-identity refers to either the ring systems R
1
and R
2
being different or, in the event that the ring systems are identical, the substituents attached to the respective ring systems are different.
Preferred thiazine-indigo compounds formed according to the invention are those asymmetric compounds wherein R
1
and R
2
are independently selected from the group consisting of
wherein Y is halogen which includes F, Cl and Br, especially Cl; R is C
1-4
alkyl, especially methyl or ethyl, aryl, OR′, SR′, NR′R″ or CONR′R″, where R′ and R″ are independently H, C
1-18
alkyl, C
5-10
cycloalkyl or aryl; a is 1, 2, 3 or 4 and b is 1, 2, 3 or 4.
More preferred thiazine-indigo compounds are those in which R
1
consists of the atoms necessary to complete a benzene ring which is optionally substituted with, for example halogen or alkyl and R
2
consists of the atoms necessary to complete a ring system which is an equally substituted benzene ring or a different ring system, e.g. naphthalene, pyridine or 1,4-benzodiazine.
The thiazine-indigo compounds formed according to the invention may be substituted on the ring systems with one or more of any of the non-water-solubilising substituents common in the art of pigments. Preferably the ring system substituents are selected from the group consisting of halogen, trifluoromethyl, nitro, cyano, carbonamide, alkyl, aryl, alkoxy, amino, alkylamino, thioalkyl, phenoxy, phenylamino, phenylthio, acyl, acyloxy or acylamino.
The term “halogen” includes fluorine and especially chlorine and bromine. The term “alkyl” or “alkoxy” comprises preferably radicals with 1 to 4 carbon atoms. The terms “alkylamino” and “phenylamino” include for example N,N-dialkylamino and N,N-diphenylamino as well as N-monoalkylamino and N-monophenylamino.
The aforementioned alkyl, alkoxy, phenyl and phenoxy substituents may themselves contain one or more substituents selected from the substituents hereinabove described.
Another category of preferred thiazine-indigo compounds according to the invention are those of the formulae (I) and (II) in which R
1
and R
2
represent the atoms necessary to complete the formation of a benzene ring which is part of a heterocyclic ring system and more specifically compounds of the formulae (Va) resp. (Vb), (VIa) resp. (VIb), (VIIa) resp. (VIIb) and (VIIIa) resp. (VIIIb)
wherein R
1
represents the atoms necessary to complete the formation of a substituted or unsubstituted aromatic or aliphatic carbocyclic or heterocyclic ring system; R
3
is hydrogen, C
1-12
alkyl or phenyl; R
6
, R′
6
, R
7
and R′
7
are independently hydrogen, an alkyl or aryl group
which are novel com
Borchert Till
Kaul Bansi Lal
Piastra Bruno
Wolf Valérie
Clariant Finance (BVI) Limited
Hanf Scott E.
Jackson Susan S.
McKenzie Thomas
Shah Mukund J.
LandOfFree
Process for the preparation of thiazine-indigo compounds and... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Process for the preparation of thiazine-indigo compounds and..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process for the preparation of thiazine-indigo compounds and... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2995490