DE2444297A1 - HETEROCYCLICALLY SUBSTITUTED FLUORANE COMPOUNDS, THE PROCESS FOR THEIR PRODUCTION AND THEIR USE AS COLOR IMAGES IN PRESSURE-SENSITIVE OR THERMOREACTIVE RECORDING MATERIALS - Google Patents

Description

Heterocyclic substituted fluoran compounds, process for their production and their use as color formers in pressure-sensitive or thermo-reactive recording materials.

The present invention relates to new fluoran compounds which are normally colorless or only slightly colored, which, however, by modifying the substituents in the 2-position of the fluorane ring, creates an intense, thank-you-green, give a grayish black or red color when they come in contact with an electron acceptor coreactant. the The present invention relates in particular to novel fluoran compounds which have one in the 6-position of the fluoran ring have nitrogen-containing heterocyclic radical which is connected to the Fludran ring via the nitrogen atom, and which is an amino group in the 2-position

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have methods of making these compounds
and their use as color formers in pressure-sensitive or thermoreactive or heat-sensitive recording material! en.

The new fluoran compounds according to the present invention correspond to the general formula:

(1)

where R-, Rp and R ,, which can be the same or different, Hydrogen atoms, alkyl groups with 1 to 12 carbon atoms, Nitro groups or halogen atoms or

Rp and R-2 taken together are a fused carbocyclic Ring, in particular a fused benzene or tetrahydrobenzene ring,

X ^, and X ₂ , which can be the same or different, hydrogen atoms, alkyl groups with 1 to 12 carbon atoms,
Alkenyl groups with a maximum of 12 carbon atoms, alkoxy groups with 2 to 8 carbon atoms, alkoxycarbonylalkyl

groups

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with 3 to 9 carbon atoms, cycloalkyl groups with 5 or 6 carbon atoms, acyl groups with 1 "to 12 carbon atoms or represent optionally substituted phenyl, naphthyl or benzyl groups,

the nitrogen-containing ring A represents a heterocyclic radical, which optionally has a further heteroatom in the Ring, in particular contains an oxygen, sulfur or nitrogen atom, and

the benzene ring B can be substituted with one or more nitro groups or 1 to 4 halogen atoms.

Halogen atoms in connection with the above substituents are preferably fluorine, bromine or chlorine atoms, very particularly preferably chlorine atoms.

If R ^, 'Rp and R, as well as X ^ and Xp are alkyl groups, they can be straight-chain or branched-chain alkyl groups. Examples of such alkyl groups are the methyl, Ethyl, n-propyl, isopropyl, η-butyl, sec-butyl or tert-butyl, octyl and dodecyl groups. R ^, Rg and R-, places preferably hydrogen or halogen atoms or alkyl groups with 1 to 4 carbon atoms such as the methyl or ethyl group.

X ^ and X ₂ as alkenyl groups are, for example, the allyl, 2-methallyl, 2-ethylallyl, 2-butnyl or the octenyl group.

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If X ^ and Xg are alkoxyalkyl or alkoxycarbonylalkyl groups, these can have 1 to 4 carbon atoms in each alkyl radical and are preferably the / ^ - methoxyethyl or yP-Äthoxyäthyl- and the / -Methoxycarbonyläthyl- or y ^ -Äthoxycarbonyläthylgruppe.

The cycloalkyl groups for the X radicals represent, for example, the Cyclopentyl group or preferably the cyclohexyl group Any substituents present in the benzyl, phenyl or naphthyl group are, for example, alkyl groups with 1 to 4 carbon atoms, alkoxy groups with 1 to 4 carbon atoms, alkoxycarbonyl radicals with 2 to 5 carbon atoms, Acyl radicals with 1 to 4 carbon atoms, nitro groups, halogen atoms or amino groups, optionally with Alkyl groups with 1 to 4 carbon atoms or substituted by benzyl. Examples of these aromatic resp. araliphatic radicals are p-methylbenzyl, p-chlorobenzyl, p-nitrobenzyl, p-tolyl, xylyl, p-chlorophenyl, p-nitrophenyl, 1-methylnaphthyl- (2) or 2-methylnaphthyl- (1).

Among the acyl groups are the alkanoyl groups with 1 to 12 Particular emphasis should be placed on carbon atoms such as the formyl, acetyl or propionyl group. Further acyl radicals are alkylsulphonyl groups with 1 to 12 carbon atoms such as the methylsulfonyl group and benzoyl or benzenesulphonyl radicals, which in the benzene ring by halogen, methyl and / or methoxy

residues can be substituted.

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In the fluoran compounds included in the formula (1) the nitrogen-containing ring A represents a heterocyclic ring connected to the fluorane ring through the nitrogen atom connected is. The heterocyclic radical can contain 3 to 12 ring members and preferably contains 5 to 6 ring members. The heterocyclic radical can also contain 1 or 2 heteroatoms as ring members. The nitrogenous ring A is e.g. a pyrrolidinyl, piperidino, pipecolino, Perhydroazepinyl, heptamethyleneimino, octamethyleneimino, 1,2,3,4-tetrahydroquinolinyl, indolinyl or hexahydrocarbazolyl group or in the event that the hetero ring contains a further heteroatom, a morpholino, thiomorpholino, Piperazino, N-alkylpiperazino group with 1 to 4 carbon atoms in the alkyl radical or a pyrazolinyl or

jJ-methylpyraz & inyl group. #

The benzene ring B can be fluorine, bromine or in particular as halogen atoms Contain chlorine. It is preferably not further substituted or contains 4 chlorine atoms.

Practically important groups of the compounds of the formula (1) correspond to the following general formula

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where R ^, R, - and Rg, which can be the same or different, Are hydrogen or halogen atoms or methyl or ethyl groups,

• X * is an alkyl radical with 1 to 8 carbon atoms, an alkoxyalkyl radical with 2 to 8 carbon atoms, a cycloalkyl group with 5 or 6 carbon atoms, an acyl group with 1 to 7 Carbon atoms, or the phenyl and benzyl radical optionally substituted in the ring by methyl or halogen, X ^ is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms; a cycloalkyl group having 5 to 6 carbon atoms, an acyl group having 1 to 7 carbon atoms or the is optionally substituted in the ring by methyl or halogen benzyl and

the nitrogen-containing ring A and the benzene ring B have the same meaning as in formula (1).

Very particularly valuable fluoran compounds of the formulas (1) and (2) correspond to the general formula

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(3)

where FU, FU and Rg have the same meaning as in formula (2) to have,

Xc is an alkyl group having 1 to 8 carbon atoms, a Represents acyl radical with 1 to 7 carbon atoms or the phenyl or benzyl radical,

Xg is a hydrogen atom, an alkyl group with 1 to 8 carbon atoms, represents an acyl radical with 1 to 7 carbon atoms or the benzyl radical,

the nitrogen-containing ring A _{1 is} a morpholino, piperazino or, in particular, a pyrrolidinyl or piperidino ring and the benzene ring B ^ can optionally be substituted with 1 to 4 halogen atoms, in particular chlorine atoms.

Of particular interest are those compounds of the formulas (1) to (3) which are listed below under A, B and C, respectively are.

A) compounds of the formula

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(4)

wherein A ^, B ₁ , R ^, Rc and Rg have the same meaning as in formula (3).

X, and Xg, which can be the same or different, »alkyl groups with 1 to 8 carbon atoms or represent the benzyl radical.

These compounds stand out as dark green color formers «

B) - compounds of the formula

(5)

wherein A ₁ , B ₁ , R ^, Rc and Rg have the same meaning as in formula (3) and

Xq is an alkyl radical with 1 to 8 carbon atoms, the benzyl or represents the phenylresf.

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These fluoran compounds are color formers which give a gray or black hue when combined with an electron acceptor co-reactant be brought into contact.

C) compounds of formula (6)

wherein A ^, B ^, R ^, Rc, Rg and Xg are those given above Have meaning and

X ^ _{0 is} an acyl radical with 1 to 7 carbon atoms, for example an alkanoyl radical with 1 to 4 carbon atoms such as the formyl, acetyl or propionyl radical, or the benzoyl, methylsulphonyl or p-tolylsulphonyirest.

These fluoran compounds are scarlet color formers.

The fluoran compounds of the formula (1) to (6) according to the invention are prepared by processes known per se. The process for the preparation of the fluoran compounds of Formula (1) is characterized in that a benzophenone of the formula

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(7)

with a compound of the formula

(8th)

wherein A, B, R ^, Rg ₁ R *, X- and X _{2 have} the meaning given above and Z * and Z _{2 are} hydrogen atoms or alkyl radicals having 1 to 4 carbon atoms such as methyl, ethyl or butyl. One of the radicals Z 1 and Z ₂ is preferably a hydrogen atom or the methyl or ethyl radical and the other radical is a hydrogen atom. Z ^ is very particularly preferably a hydrogen atom and Z _{2 is} a hydrogen atom or the methyl group.

The reaction is preferably carried out at a temperature of 10 to 100 ^° C., the reaction components of the formulas (7) and (8) being reacted in the presence of an acidic condensing agent.

Examples of suitable condensing agents are acetic anhydride, ^{1 509813/1099}

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Sulfuric acid, zinc chloride or phosphorus oxychloride. The reaction is preferably completed by adding a basic compound. The base can do both organic as well as inorganic in nature. Examples are the alkali hydroxides such as sodium hydroxide and potassium hydroxide as well as aliphatic Amine.wie triethylamine and Trihydroxyethylamine.

The starting materials of the formula (7) are generally prepared by adding a phthalic anhydride the formula

with a compound of the formula

OZ,

reacts, in which Z ^ is hydrogen or an alkyl group having 1 to 4 carbon atoms and the rings A and B have the meanings given above. This reaction is preferably carried out in an organic solvent such as acetone, benzene, toluene, xylene or a chlorobenzene, preferably at or below the boiling point of the solvent.

The compounds of formula (10) can thereby be prepared

terocyclic Ba 509813/1099

be that a heterocyclic base LA. NH, wherein the ring A

has the meaning given above, is condensed with resorcinol or a monoalkyl ether thereof "at a temperature between 50 and 250 ⁰ C and optionally under pressure. This reaction can be carried out in the presence or absence of a condensing agent. Examples of suitable condensing agents are zinc chloride, aluminum chloride or On the other hand, the compounds of the formula (10) can also be prepared by reacting m-hydroxy or m-alkoxyaniline with a cf, i-dihaloalkane, the halogen atoms of which are, for example, bromine or chlorine, but are generally bromine atoms.

Compounds of the formula (1) in which X ^ or Xp or both groups are acyl radicals can be prepared by treating a compound of the general formula (1) in which at least one of the radicals X ^ and X _{2 is} a hydrogen atom with an acylating agent with a maximum of 12 carbon atoms, for example reactive functional derivatives of aliphatic carboxylic acids or sulphonic acids, in particular fatty acid halides and anhydrides such as acetyl chloride, acetyl bromide or acetic anhydride, or of aromatic carboxylic acids or sulphonic acids such as the benzoic acid halides or benzene sulphonic acid halides.

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The acylation is generally carried out by known methods carried out, for example, in the presence of an acid binding agent such as an alkali carbonate or a tertiary nitrogen base such as pyridine and optionally in the presence of an inert organic solvent such as acetone, isopropanol, Chlorobenzene or nitrobenzene.

The new fluorans represent more or

are less colorless compounds that are particularly valuable when combined with an acidic co-reactant, i.e., a Electron acceptor substance, are brought into contact. Typical examples of coreactants are attapulgus clay, Silton clay, silicon dioxide, bentonite, halloysite, aluminum oxide, Aluminum phosphate, kaolin, or any acidic Clay or an acidic polymeric material such as a phenolic polymer, an alkylphenol acetylene resin, a maleic rosin rarz or a partial or complete hydrolyzed polymer of maleic anhydride with styrene, ethylene, vinyl methyl ether or carboxypolymethylenes.

Preferred coreactants are Attapulgus clay, Silton clay or a phenol-formaldehyde resin, these being electron acceptors preferably in the form of a layer on the front side of the

Receiving sheet are applied.

As indicated above, the fluoran compounds react

of formula (4) as green color former, while compounds' .- 509813/1099

of the formula (5) act as gray or black color formers. On the other hand, the fluoran compounds react Formula (6) as a creator of red or scarlet colors.

By varying the structure of the fluorans of the above formulas, certain properties can be "incorporated"; so e.g. the color mentioned in the previous paragraph, the color stability and compatibility with other color formers in the mixture as well as any solubility properties that allow greater flexibility in the selection of the microencapsulation and other types of application.

As already mentioned, the new color formers are particularly suitable for use in so-called pressure sensitive recording materials. Such a material includes, for example, at least a pair of sheets, which contain at least one color former of the formula (1) dissolved in an organic solvent and preferably contained in pressure breakable microcapsules, and an electron acceptor substance. The color former then gives when it comes into contact with the electron acceptor substance, a colored mark on the points where the pressure is applied.

In order to prevent the color formers contained in the pressure-sensitive copying material from becoming active, they are from • 509813/1099

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the electron acceptor substance separated. This is done in the Usually achieved by incorporating the color formers into foam, sponge or honeycomb-like structures. Preferably However, the color formers are enclosed in microcapsules.

Are the colorless color formers of the formula (1) in an organic one Solvent dissolved, they can be subjected to a microencapsulation process and then used for production used by pressure sensitive papers. If the capsules are pressed, for example with a pencil, broken and the color former solution is transferred in this way to an adjacent sheet, which is covered with a substrate is coated, which can act as an electron acceptor, a colored image is produced. The coloring results from the dye formed, which absorbs in the visible region of the electromagnetic spectrum.

Some processes for the production of microcapsules have been known for a long time. Known methods are for example in U.S. Patent Nos. 2,183,053, 2,800,457,

2 800 458, 3 265 630, 2 964 331, 3 418 656, 3 418 250,

3 016 308, 3 424 827, 3 427 250, 3 405 071, 3 171 878 and

2,797,201. Further procedures are in the UK Patent 989 264 and most notably in British Patent 1,156,725. Any of these "procedures

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and other methods are suitable for encapsulating the invention Color formers.

The new color formers are preferably encapsulated in the form of a solution in organic solvents. Examples of suitable solvents are preferably non-volatile solvents, for example polyhalogenated diphenyl, such as trichlorodiphenyl and its mixtures with liquid paraffin, tricresyl phosphate, di-n-butyl phthalate, dioctyl phthalate, trichlorobenzene, nitrobenzene, trichloroethyl phosphate, petroleum ether, hydrocarbon derivatives such as paraffinic oils, etc. Diphenyl or triphenyl, chlorinated or hydrogenated condensed aromatic hydrocarbons. The capsule walls are preferably formed by coacervation forces acting uniformly around the droplets of the color former, the encapsulating material being composed of gelatin, as is described, for example, in US Pat. No. 2,800,457. The capsules can, however, preferably also be produced from an aminoplast or modified aminoplast by polycondensation, as is described in British patents 989,264 and 1,156,725.

A preferred arrangement is one in which the encapsulated color former is in the form of a layer on the back of a transfer sheet and the electron acceptor

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substance are applied in the form of a layer to the front of a receiving sheet. In another preferred material, the new fluorans are used together with one or more other known color formers, such as crystal violet lactone, benzoyl leucomethylene blue or a bisindolyl phthalide, such as 3,3-bis- (1in-octyl-2'-methylindol-3- ^t -yl) phthalide, encapsulated.

The color formers of the formula leather of the sub-group formulas containing microcapsules are used in the manufacture of pressure-sensitive copying materials of the various per se known types, such as, for example, so-called "chemical transfer papers" and "chemical self-contained (Self-writing) papers (chemical self-contained papers) "are used. The different systems differ mainly through the arrangement of the capsules, the color reactants and the carrier material from one another.

The microcapsules can be in a lower layer of the upper Sheet and the color reactants, i.e. the electron acceptor and the coupler, may be contained in the overcoat layer of the lower sheet. The components but can also be used in the paper pulp. Such systems are referred to as "chemical transfer systems".

Another arrangement lies in the "self-contained papers" before. In this case, those containing the color former are 509813/1099

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Microcapsules and the color reactants in or on the same Sheet in the form of one or more individual layers or in the paper pulp.

Such pressure-sensitive copying materials are described, for example, in U.S. Patents 3,516,846, 2,730,457, 2,932,582, 3,427,180, 3,418,250 and 3,418,656. Other systems are in the UK patents 1 042 597, 1 042 598, 1 042 596, 1 042 599, 1 053 935 and 1 517 650. Those containing the color formers of the formula (1) Microcapsules are suitable for each of these systems and for other systems.

The capsules are preferably attached to the carrier by means of a suitable adhesive. Because paper is preferred Is carrier material, these adhesives are primarily paper coating agents, such as e.g. gum arabic, polyvinyl alcohol, kydroxymethyl cellulose, Casein, methyl cellulose and dextrin.

The term "paper" used here is not limited to normal papers made of cellulose fibers, but also to understand those papers in which the cellulose fibers are partially or completely replaced by fibers made from synthetic polymers.

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The novel fluoran compounds according to the invention can also be used as color formers in a thermoreactive recording material which contains at least one carrier, a binder, a color former and an electron acceptor sub-. punch contains. Thermoreactive recording systems include heat-sensitive recording and copying materials and papers. These systems are used, for example, for recording of information, e.g. in electronic computers, remote

'» or

printers or teleprinters / used in measuring instruments.

The image generation (marking generation) can also be carried out manually with a heated pen. Another facility laser beams are used to generate markings by means of heat. The thermoreactive recording material can so be constructed so that the color former is dissolved or dispersed in a binder layer and in a second Layer the developer and the electron acceptor substance are dissolved or dispersed in the binder. Another It is possible that both the color former and the developer are dispersed in one layer. That Binder is imagewise softened in specific areas by means of heat and at these points the dye becomes formed, since only at these points on which heat is applied becomes, the color former with. the electron acceptor substance comes into contact.

The developers are the same electron acceptor substances as they are in pressure-sensitive papers ^! 509813/1099

be used. For practical reasons, the developer should be solid at room temperature and melt or soften above 5O ⁰ C. Examples of such products are the already mentioned clays, phenolic resins, phenolic compounds such as 4-tert-buty! Phenol, 4-phenylphenol, 4-hydroxydiphenyloxide, ^ - naphthol, 4-hydroxybenzoic acid methyl ester, f -naphthol, 4-hydroxyacetophenone, 2, 2'-dihydroxydiphenyl, 4,4'-isopropylidene diphenol, 4,4'-isopropylidene-bis (2-methylphenol), 4,4'-bis (hydroxyphenyl) valeric acid, hydroquinone, pyrogallol, phloroglucinol, p- , m-, o-hydroxybenzoic acid,

• Gallic acid, i-hydroxy-2-naphthoic acid, boric acid and the aliphatic dicarboxylic acids such as tartaric acid, oxalic acid, maleic acid, citraconic acid or succinic acid.

Meltable, film-forming binders are preferably used. These binders should be water soluble because the fluorans and the developer are insoluble in water. The binder should be able to take the color former and to disperse and fix the developer at room temperature. This is how the two reactive components lie in the material in non-associated form. When exposed to heat, the binder softens or melts, so that the color former can come into contact with the developer and form a dye.

Water-soluble or at least water-swellable binders are e.g. hydrophilic polymers such as polyvinyl alcohol,

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Polyacrylic acid, hydroxyethyl cellulose, methyl cellulose, Carboxymethyl cellulose, polyacrylamide, polyvinylpyrrolidone, gelatin or starch.

If the color former and the developer are present in two separate layers, binders which are insoluble in water, i. Binding agents soluble in non-polar or only slightly polar solvents, such as natural rubber, synthetic Rubber, chlorinated rubber, alkyd resins, polystyrene, styrene / butadiene copolymers, polymethyl methacrylates, Ethyl cellulose, nitrocellulose or polyvinyl carbazole are used will. The preferred arrangement, however, is that in which the color former and the developer are in one layer are contained in a water-soluble binder.

The coatings (layers) of the thermoreactive material can contain further additives. To improve the whiteness, to make it easier to print on the papers and to prevent the heated pen from sticking, these materials can contain, for example, talc, TiO ₂ , ZnO or CaCO ₃ . In order to ensure that the dye is only formed within a limited temperature range, substances such as urea, thiourea. Acetanilide, phthalic anhydride or other corresponding fusible products are added, which induce the simultaneous melting of the "color former and the developer.

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Typical thermoreactive recording materials in which the color formers according to the invention are used, for example, in German patent application 2 228 581, in French patent specification 1 524 826, in Swiss patent specification 407 185, in German patent application 2 110 854 and Swiss patents 164 976, 444 196 and 444 197.

The following examples are intended to explain the invention in more detail without, however, restricting it thereto. The ones specified therein Percentages are based on weight, unless otherwise stated.

example 1

2- (N, N-dibenzylamino) -6- N -pvrrolidinyl-fluoroan

A mixture of 77.75 g of 2'-carboxy -? .- hydroxy-4-N-pyrrolidinylbenzophenone, 75.6 g of N, N-dibenzyl-p-anisidine and 250 ml of 98 % sulfuric acid are heated at 60 ° C. for 5 hours stirred and then poured into 2,750 ml of ice water, whereby a solid is precipitated. The solid is abfiltrierc, washed with water and added to a mixture of 500 ml water, 250 ml of methanol and 26.8 g of NaOH at 70 ⁰ C. The mixture is heated to boiling for 2 hours and then cooled to 85 ° C. The solid is filtered off, washed with hot water and then recrystallized from methanol / acetone and dried.

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86 g of white platelet-shaped crystals with a melting point of 180 ^° C. are obtained. / C max. In 95 # acetic acid: 435, 462 and 607 nm.

A solution of 2- (N, N-dibenzylamino) -6-N-pyrrolidinylfluorane in a solvent based on hydrogenated Terphenyl gave a dark green print when applied to paper coated with Silton clay. Absorption maxima are found at A 444 and 602 nm.

The benzophenone derivative used as the starting material in this example is prepared as follows: A mixture of 74 g of phthalic anhydride, 81.5 g of 1- (3 ^f -hydroxyphenyl) pyrrolidine and 335 ml of xylene are heated to 125 ° C. for 6 hours and then cooled to 25 ° C. The precipitate is filtered off, washed with methanol and dried. This gives 110% of a yellow solid with a melting point of 194 ° C. after recrystallization from ethanol.

For example , 2-2-ethylamino-6-N-pyrrolidinyl-fluorane

A mixture of 9.33 g of 2'-carboxy-2-hydroxy-4-N-pyrrolidinylbenzophenone, 4.54 g of N-ethyl-p-anisidine and 30 ml of 98 % sulfuric acid is stirred at 60 ° C. for 5 hours and then

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placed in 330 ml of ice water. A solid is precipitated in this way, which is filtered off, washed with water and then added to 75 ml of methanol and 16.5 ml of triethylamine. The mixture is heated to boiling with stirring for 12 hours and cooled ^{to 0 ° C.} The precipitate is filtered off, washed with methanol and dried. This gives 8.32 g of 2-ethylamino-6-N-pyrrolidinyl-fluorane in the form of a white solid.
/ ζ max. in 95% acetic acid: 434, 457 and 602 nm.

A solution of this compound in benzene is colorless and gives a black color on contact with silicon dioxide, a greenish black on Attapulgus or Silton clay and a green on phenolic resin.

Example 3 '

2-N-Acetvl-N-ethvlamino-6-N-pyrrolidinvJ-fluoran

A mixture of 4.0 g of 2-ethylamino-6-N-pyrrolidinyl-fluoraή, 12 ml of acetic anhydride and 0.4 ml of pyridine is stirred for 4 hours at 120 ⁰ C. The solution is then evaporated to dryness, the residue is taken up in 20 ml of 10% sodium carbonate solution and extracted with ether. After drying and evaporation of the ether, 3.2 g of 2-N-acetyl-N-ethylamino-6-N-pyrrolidinyl-fluorane are obtained.
/ <max. in 95% acetic acid: 374, 496 and 528 nm.

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This compound forms a red color when it comes into contact with electron accepting substances such as silicon dioxide brings.

Example 4

2- (N, H-dibenzylamino) -6-N-pyrrolidinyl-fluorane

A mixture of 15.5 g of 2 '~ carboxy-2-ethoxy-4-N-pyrrolidinylbenzophenon and 14.45 g of p-dibenzylamino-phenol is stirred for 5 hours at 60 ⁰ C in 50 ml of 98 & engined sulfuric acid, then to 25 ° C cooled and stirred into a mixture of 100 ml of water and 450 g of ice. The pH of the cooled mass is adjusted to 8.5 with the aid of 125 ml of 35% ammonia. The precipitate is filtered off, washed with water and dried at 70 ° C. in vacuo. 19.7 g of 2-dibenzylamino-6-N-pyrrolidinyl-fluorane are obtained in this way. The product is recrystallized from a mixture of methanol and acetone. As a result, colorless platelet-shaped crystals with a melting point of 180 ^° C. are obtained. The product is identical to the color former obtained according to Example 1.

The starting product used according to this example as a starting product 2 '-carboxy-2-ethoxy-4-N-pyrrolidinyl-benzop} rienone. is made as follows:

To a mixture of 31.1 g of 2 ^f -carboxy-4-N-pyrrolidinyl-2- 'hydroxy-benzophenone, 39.6 ml of diethyl sulphate and 240 ml

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Acetone, a solution of 16.8 g of potassium hydroxide in 50 ml of water is added dropwise ^{at 35 ° C., distributed over 4 hours.} The reaction mixture is then ^{stirred at 35 to 40 °} C. for a further 20 hours. A solution of 11.2 g of potassium hydroxide in 50 ml of water is then added and the mixture is brought to the boil and refluxed for 2 hours. The solvent is evaporated until the remaining solution has a temperature of 91 ° C. The residue is ^{kept at 96 °} C. for 30 minutes and then cooled to ⁰ ° C. by adding ice. About 25 ml of 28 % hydrochloric acid is added and the pH is adjusted to a value between 3 and 4 as a result. The reaction product is precipitated in the form of a white suspension. After filtering off and washing with water, 32.0 g of 2'-carboxy - ^ - N-pyrrolidinyl - ^ - ethoxybenzophenone with a melting point of 184 to 185 ° C. are obtained.

Example 5

2rAnilino-3-diethyl-6-N-Pvrrolidinvl-fluorane

15 g of 2'-carboxy-2-hydroxy-4-N-pyrrolidinyl-benzophenone and 9.9 g of 4-anilino-m-cresol are dissolved in 50 ml of 96% sulfuric acid and stirred for 2 hours at 60 ⁰ C. The product is washed in the same manner as described in Example 2 and recrystallized from ethyl acetate / hexane. Fp.

above 260 ⁰ C. AT max in 95% acetic acid. 3Ö0, 450, 509813/1099

and 585 mn. When applying the compound on a with Silton clay According to example 1 coated paper a gray print is obtained, der.Absorptionsmaxima at / C 453 and 575 mn revealed.

By applying the method according to Examples 1 to 5 on the corresponding starting materials, the fluoran compounds of the formula (11), as shown in the table below, produced:

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Ö CM ω CM ■ · ■ ι O VO - 28 - CM I. CM Ι O CO ω ω 00 to VO ο Eh
I. ιη ιη in ιη VO CM VO O VD ο ο ο m CM • Ρ -d · ιη in νο C- CM m H
,. ι -Cf O * * CM CO co O VO CM O VD CM VO vo £ <- O to O) • cf * -Cf to VO CX \ O ο <f ιη to CM -Cf in -Cf : § σ » ο ο ο to vo O O in (Q ιη VO νο VO VO <j \ VO to • Η bO σ \ σ » to CM vo O ο • Η - • Α ιη ιη CM νο C— O -Cf VO to (Ο
W. -Cf • el -cf CM
■ -Cf <f τ- -Cf T- ε
• Η W. m in to ι
τ- σ » -Cf VO 3 O CO ι to
-ef to to
<f CM to 3 H <f
-Cf CM CU to to _ο CM ω τ- fv. O Ό in τ- O c * - to T- <f 0Λ in T- \ * σ. CM • τ
ι CM CM ω CM T- CM CM CO ti. O -Cf co CM CM O C "- CM -Cf T- T- CM CM τ- τ- f J CM CM νο U T- τ- I. VO έ ü
I. σ \ CM in κ " Ü O VO ω O 0 <f ω τ- in U T
CM Γ j] CM ü ο • Ο to n- β fi O CM
O to O
I. O
I. VO T
CM 0 JfV ü ffi CM ε to ^Ä . I. O
I. ε ε W. ta κ O CM
O O
I. H to
T- «
VD ΟΛ O e vo
τ- • Η
H ε S. ε e ₌ O to
T ~ VO C- co O
τ- T-
T- ε in
τ- • υ CM
T- Γ P * ν * CM T " τ- I Φ Ή · Η O) P

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at
spat
No. ■ ^A 2 ^X 11 ^X 12. Mp ° C A maxima in nm Silton tone 17th N-pyrrolidinyl -O CH ₃ 206-208 95% acetic acid 458 576 18th It -CHO nC ₄ H _g 158-160 444 456 605 504 19th Il -CHO, ⁿ - ^C 8 ^H i7 120-121 501 532 504 20th It -COCH ₃ HC ₄ H ₉ 112-115 501 532 500 21 Il -COCH ₃ ⁿ " ^C 8 ^H i7 77-79 498 529 500 cn
ο 22nd Il -CO-Q HC ₄ H ₉ 177-178 498 529 500 co
00 23 It -COhQ » 199-200 501 535 504 to 24 N-piperidino H 143-144 503 535 450 584 1099 439 467 605

Application examples

Example 25

Manufacture of pressure-sensitive copier paper

A 3 g 2-Dibenzylaminc-6-N-pyrrolidinyl-fluoran containing solution in 100 g of hydrogenated terphenyl is at 50 ⁰ C in 100 of a 12% pig skin gelatin solution emulsified g. It

100 g of a 12% gum larabicum solution are then added

and then 200 ml of water at 5O ⁰ C was added. The emulsion is poured into 600 g of ice / water and stirred for 3 hours to complete the coacervation. The resulting slurry of microcapsules is coated on a paper and dried. If the coated side is brought into contact with a second sheet which is coated with Silton clay, attapulgite clay or a phenolic resin, a dark green image is obtained after the application of pressure while writing. Similar effects can be obtained using any of the other color formers described in Examples 2 to 24.

Example 26 Manufacture of pressure sensitive copier paper

A 1.6 g of 2-dibenzylamino-6- ^l ^ Γpyτrolidinyl-fluoran, 0.6 g of 3 »3-bis (1'-n-octyl-2 ^l -methylindol-3 ^l -yl) phthalide, 0 , 1 g and 0.6 g of benzoyl Crystallviclettlacton solution containing in 100 g of hydrogenated terphenyl is emulsified at 50 ⁰ C in 100 g of 12 # hydrochloric pigskin gelatin solution

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. 31 - 2A4A297

greed. Then, at 50 ⁰ C 100 of a 12% gum arabic solution g and finally 200 ml 'of water was added. The emulsion is poured into 600 g ice / water and stirred for 3 hours to complete the coacervation. The obtained slurry of microcapsules is to If the coated side is brought into contact with a second sheet which is coated with Silton clay or attapulgite clay, a gray-black image is obtained after the application of pressure by writing.

Example 27 Manufacture of a thermoreactive PaOier

6 g of an aqueous, 1.6? 6 2-dibenzylamino-6-N-pyrrolidinylfluoran, 0.8% of 3,3-bis ^(t i -n-octyl-2 ^l -methylindol-3 -yl ^I) »phthalide , 0.1 % crystal violet lactone and 6.7 5b polyvinyl alcohol containing aqueous dispersion are mixed with 134 g of an aqueous solution containing 14% 4,4'-isopropylidenediphenol and 6 % polyvinyl alcohol. The mixture is applied to paper and the coated paper is dried. If you touch with a heated pen, a gray-black marking with excellent lightfastness is obtained.

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Example 28

Manufacture; a thermoreactive paper

If the color former used according to Example 27 is replaced by 2-dibenzylamino-6-N-pyrrolidinyl-fluorane and 3,3-bis- (i'-noctyl-2'-methylindole-3 ^f -yl) phthalide in a ratio of 6: 1 , the resulting system gives a deep black typeface.

509813/1099

Claims (10)

Claims; . 1. Heterocyclically substituted fluorane compounds of general formula. wherein R ^, Rp and R ^, which are the same or different can, hydrogen atoms, alkyl groups with 1 to 4 carbon atoms, Are nitro groups or halogen atoms, or Rp and R, together are a condensed carbocyclic Form a ring, X ^ and X ₂ , which can be the same or different, hydrogen atoms, alkyl groups with 1 to 12 carbon atoms, alkenyl groups with a maximum of 12 carbon atoms, alkoxyalkyl groups with 2 to 8 carbon atoms, alkoxycarbonylalkyl groups with 3 to 9 carbon atoms, cycloalkyl groups with 5 or 6 carbon atoms, Acyl radicals with 1 to 12 carbon atoms or the optionally substituted benzyl, phenyl or naphthyl group and the nitrogen-containing ring A is a heterocyclic radical '509813/1099 24U297 represents, which optionally contains a further heteroatom as a ring member, and the benzene ring B can be substituted by nitro groups or 1 to 4 halogen atoms. 2. fluoran compounds according to claim 1 corresponding to the general formula wherein R ,, R ₁ WIiRg, which can be the same or different, are hydrogen or calogen atoms, methyl or ethyl groups, X, an alkyl group having 1 to 8 carbon atoms, a Alkoxyalkyl group having 2 to 8 carbon atoms, a cycloalkyl group having 5 or 6 carbon atoms Acyl radical with 1 to 7 carbon atoms or which is optionally substituted in the ring by methyl or halogen Is phenyl or benzyl, X ^ is a hydrogen atom, an alkyl group of 1 to 8
Carbon atoms, a Cyclöalkyigruppe with 5 or 6 '509813/1099 24U297 Carbon atoms, an acyl radical containing 1 to 7 carbon atoms or the benzyl radical optionally substituted in the ring by methyl or halogen and the nitrogen-containing ring A and the benzene ring B have the same meaning as in claim T. 3. fluoran compounds according to claim 2 corresponding to general formula wherein R., Rc and R ^ have the same meaning as in claim 2 to have, Xc is an alkyl group having 1 to 8 carbon atoms Acyl radical with 1 to 7 carbon atoms that is phenyl or benzyl, Xg is a hydrogen atom, an alkyl group with 1 to 8 carbon atoms, an acyl group with 1 to 7 carbon atoms or the benzyl group and the nitrogen-containing ring A ^ is a pyrrolidino, piperidino, morpholino or piperazine ring and the benzene ring B ₁ additionally has 1 to 4 halogen atoms can be substituted. 509813/1099 4. fluoran compounds according to claim 3 corresponding to general formula wherein A ^, B ₁ , R ^ ₁ Rc and Rg have the same meaning as in Have claim 3 and Xj and Xg, which can be the same or different, Are alkyl groups with 1 to 8 carbon atoms or the benzyl radical. 5. fluoran compounds according to claim 3 corresponding to. general formula 509813/1099 -37- 24U297 wherein Aj ,, B ^, R ^ ,, Rc and Rg have the same meaning as in claim 3 and Xq is an alkyl group having 1 to 8 carbon atoms or the benzyl or phenyl radical. 6. fluoran compounds according to claim 3 corresponding to the general formula wherein A,., B ^, R /, Rc and Rg have the same meaning as in the claim 3 habers. and Xq has the same meaning as in claim 5 and is an acyl radical having 1 to 7 carbon atoms. 7 · Process for the preparation of fluoran compounds according to Claims 1 to 6, characterized in that a benzophenone of the general formula 509813/1099 24U297 with a compound of the general formula reacted, where in the above formulas A, B, R ₁ , R ₂ , R ,, X ^ and Xp have the same meaning as in claim 1 and Z ₁ and Z _{2 represent} hydrogen atoms or alkyl groups having 1 to 4 carbon atoms. 8. Process for the preparation of fluoran compounds according to claim 1 ,. wherein X. or X- or both Groups represent acyl radicals with 1 to 12 carbon atoms, characterized in that a compound according to claim 1, in which at least one of the radicals X ₁ and X _{2 is} petroleum, is reacted with an acylating agent with at most 12 carbon atoms. 9. ' Use of the heterocyclically substituted fluoran compounds according to claims 1 to 6 as color former in pressure-sensitive or thermoreactive recording media. 509813/1099 10. Use according to claim 9, characterized in that the color former is provided in a pressure-sensitive microcapsule and the pressure-sensitive recording material additionally contains an electron acceptor substance> z. 11, use according to claim 9 of a fluoran compound according to Claim 1 as a color former in a thermoreactive preparation which, in addition to the color former, contains an electron acceptor substance and contains a binder. 509813/1099 ORIGINAL INSPECTED