DE2520148C2 - - Google Patents

Description

The chromogenic furo [3,4-b] quinoxalin-3-ones according to the invention are essentially colorless solids that are also colorless in solution, but upon reaction contact with an acidic substance in a dark colored state pass over.

When used in marking-forming systems a marking in the desired areas of a Carrier web or a carrier sheet causes that a local reaction contact between the chromogenic Fabric and the acidic fabric on or in the train or the sheet is brought about. The chromogenic substance can be applied to the carrier sheet by transfer will be or already exist in it. By the Reaction contact is made in the area to be marked achieved a dark color.  

Pressure sensitive, marker forming systems included color-forming components on and / or in one or several carrier sheets, the color-forming components by means of a material that can be broken by pressure are separated from each other. If all components are on a single sheet of paper an "autogenous reactive" recording material. Are the color-forming components on separate sheets arranged, then one speaks of a "transmission system". Multiple copy systems can by Stacking sheets that are made a receiving surface on top and on hers Have a transfer surface on the bottom.

For the most commonly used copy material is a solution of basic chromogenic substances, for example Phthalides, pyromellitides and fluorans, in microscopic small capsules included, which turn out to be Layer on one surface of a transfer sheet located while the adjacent side of the recording sheet with a Lewis acid, i.e. H. with an electron acceptor, is sensitized. It is a large number of reagents of the Lewis acid type known in connection used with basic chromogenic substances can be. The most common are acidic clays, such as attapulgite, silton clay, zeolite, bentonite, halloysite, Kaolin and silicon dioxide. However, they are also sour reacting polymeric materials used, either alone or in combination with acidic clays. Examples such polymeric substances are phenolic polymers, such as Phenol-formaldehyde and phenol-acetylene polymers, Maleic turpentine resins, partially or completely hydrolyzed styrene-maleic anhydride copolymers, Carboxy-polymethylene and partially or completely  hydrolyzed vinyl methyl ether-maleic anhydride copolymers and mixtures of these substances. A big Number of such acidic polymers and solvents for these and for the chromogenic substances are in DE-PS 12 75 550.

The chromogenic furo [3,4-b] quinoxaline 3-one of the general formula given in claim 1 (I) for use in those described above pressure-sensitive recording systems are suitable, have high color intensity and high light fastness. Similar compounds, namely chromogenic Furo [3,4-b] pyrazin-5-ones are in DE-OS 22 59 409 described.

To clarify what can be achieved according to the invention technical progress over the state of the art, as it is known from DE-OS 22 59 409, were Comparative experiments carried out in which the inventive Compounds of Examples 18 and 31 den Compounds of Examples 1 and 2 of DE-OS 22 59 409 were compared.

These are the following connections:  

Compound A (invention)

1- (1-Ethyl-2-methylindol-3-yl) -1- (2-ethoxy-4-diethylamino phenyl) -1- [H] -3- [H] -furo [3,4-b] -quinoxalin-3-one (compound from Example 18).

Compound B (comparison)

This is the one corresponding to compound A. Connection, however, instead of the Quinoxaline ring has a pyrazine ring (compound of Example 1 of DE-OS 22 59 499).

Compound C (invention)

1,1-bis (2-ethoxy-4-diethylaminophenyl) -6,7-dimethyl-1- [H] -3- [H] -furo [3,4-b] quinoxalin-3-one (compound of Example 31).

Compound D (comparison)

This connection corresponds to compound C with which Difference that they have one instead of the quinoxaline ring Has pyrazine ring. (It is the connection of example 2, the first on page 8 DE-OS 22 59 409 is disclosed).

The compounds A-D become pressure sensitive in the usual way Recording materials introduced and then developed in the usual way. The development the colors were made with the three materials X, Y and Z, where X for Silton clay, Y for a zinc modified p-octylphenol resin and Z for a zinc modified p-phenylphenol resin. Then the reflection intensity at the absorption maximum using measured by a reflection spectrophotometer. The one here Results obtained are as follows Compiled table.  

table

From the table above it can be seen that the inventive Compounds A and C a much lower one Have initial reflection intensity than that corresponding comparison compounds, which instead of Quinoxaline ring have a pyrazine ring which means that they have a much more intense initial color surrender.

Scheme I illustrates the step-by-step preparation of the compounds of the invention. The implementation of a Quinoxaline dicarboxylic anhydride (III) with a substrate reactant (K, L, M, T, W or Z) results in one Quinoxaline keto acid (II). This is then with a substrate reactant (K, L, M or T) to the inventive chromogenic furo [3,4-b] quinoxalin-3-ones (I) implemented.

The quinoxaline dicarboxylic anhydride (III) has in the 6- and 7-position of the quinoxaline the groups R₁ and R₂. R₁ and R₂ are hydrogen, chlorine, a nitro, C₁-C₆-alkyl-, C₁-C₆-alkoxy- or di-C₁-C₆-alkylamino- Radical, wherein the C₁-C₆ alkyl and C₁-C₆ alkoxy groups Methyl or methoxy, ethyl or ethoxy, propyl or Propoxy (including isopropyl or isopropoxy), Butyl or butoxy (including isobutyl or isobutoxy and tert-butyl or tert-butoxy), pentyl or Pentoxy (including the corresponding isomers), Hexyl or hexoxy (including the corresponding Mean isomers).

The substrate reactant 4-aminophenyl (K) has R₃ in the 2-phenyl position, R₄ in the 3-phenyl position, R₅ and R₆ on the 4-position amino group and R₇ in the 6 position. R₃, R₄ and R₇ are hydrogen, Chlorine, a nitro radical, a C₁-C₆ alkyl radical, a C₁-C₆ alkoxy radical or a di-C₁-C₆-alkyl  amino radial. R₅ and R₆ represent hydrogen, one Phenyl or benzyl group or a C₁-C₆ alkyl group represents, when R₅ or R₆ is a phenyl or Benzyl group, the other residue is either hydrogen or a methyl radical.

The substrate reactant 3-pyrryl (L) has R₈ in the 2- and in the 5-pyrrole position and R₉ in the 1-pyrrole Position. The substrate reactant 3-indolyl (M) has R₈ and R₉ in the 2- or 1-indole position and R₁₀ in the 5-indole position. The substrate rectant 3-benzoindolyl (T) is in the 2- and 1-benzoindole position in R₈ and R₉ substituted. The substrate reactant 2-pyrryl (W) has the substituent R₉ in the 1-pyrrole position. The substrate reactant is (2-alkoxy-5-aniline) phenyl (Z) with R₁₁ in the 2-phenyl position and with R₁₂ on the aniline Nitrogen substituted.

In these reactants, R₈ represents hydrogen, a C₁-C₆- Alkyl radical, a C₁-C₆ alkoxy radical or a phenyl Radical represents. R₉ represents hydrogen, a C₁-C₆ alkyl radical or represents a phenyl radical. R₁₀ is hydrogen, a C₁-C₆ alkyl or alkoxy radical. R₁₁ means a C₁-C₆ alkoxy radical and R₁₂ hydrogen, a methyl or ethyl radical.  

The invention is illustrated below by means of examples explained for the preparation of the connections. Other compounds of the invention can be similar Way using appropriately substituted starting materials getting produced.

Example 1 Preparation of 1,1-bis (2-methyl-4-diethylaminophenyl) - 1- [H] -3- [H] -furo [3,4-b] quinoxalin-3-one.

First, N, N-diethyl-m-toluidine (unit K, in which R₃ = CH₃, R₄ = H, R₅ = R₆ = C₂H₅ and R₇ = H) with 2,3-quinoxalic anhydride (I, wherein R₁ = R₂ = H) combines to 2- (2-methyl-4-diethylaminobenzoyl) -3-quinoxalic acid to obtain. For this purpose, 0.1 mol of toluidine and 0.1 mol of anhydrous Aluminum chloride 50 ml ice-cold methylene chloride added. This system uses 0.02 mole of quinoxalic anhydride added and the system overnight stirred until the reaction is complete. The system is steam distilled and the solid residues Filtration separated. The solid residue is then in Dissolved ammonia and with dilute hydrochloric acid at a pH of 2 precipitated again.

A mixture of 0.9 g of the quinoxalic acid obtained, 0.4 g of N, N-diethyl-m-toluidine (unit K, where R₃ = CH₃, R₄ = H, R₅ = R₆ = C₂H₅ and R₇ = H) and 5 ml of acetic acid rectified for five minutes and poured into ice and ammonia. The system is extracted twice with toluene, dried in the toluene using sodium sulfate and then the toluene evaporates. The residue is dissolved in chloroform and using Chloroform as eluent on aluminum hydroxide  chromatographed. The solvent of the eluted Fraction is evaporated and the material is three times recrystallized from toluene-petroleum ether and once from toluene. The 1,1-bis (2-methyl-4-diethylaminophenyl) -1- [H] -3- [H] -furo [3,4-b] quinoxalin-3-one obtained owns a melting point between 181 and 186 ° C. A chloroform solution this product results on one with one Phenolic resin or Silton clay or a combination these two fabrics coated paper a brilliant green Colour.

The 2- (2-methyl-4-diethylaminobenzoyl) -3-quinoxalic acid Example 1 can also be used with other units K, L, M, T combined to form further compounds according to the invention be (Table I).

Table I

Example 8 Preparation of 1- (1-isopentyl-2-methylindol-3-yl) -1- (2-ethoxy-4-diethylaminophenyl) -1- [H] -3- [H] -furo [3,4-b] - quinoxalin-3-one.

First, N, N-diethyl-m-phenetidine (K, in which R₃ = OC₂H₅, R₄ = H, R₅ = R₆ = C₂H₅, R₇ = H) with 2,3-quinoxalic anhydride (III, wherein R₁ = R₂ = H) combines to 2- (2- Obtain ethoxy-4-diethylaminobenzoyl) -3-quinoxalic acid. To do this, 0.1 mole of phenetidine and 0.1 mole anhydrous aluminum chloride 100 ml tetrachloroethane added at about 5 ° C. 0.05 mole of 2,3-quinoxalic anhydride are slowly added to this system, whereby the temperature is maintained. Then leaves to raise the temperature to 15 ° C and stir one Hour after which the solution on ice and a diluted Pour hydrochloric acid solution. The pH of the system  is set to 2 and 10.5 g of one crystallized oil separated. After recrystallization several times one gets from ethyl alcohol water Product with a melting point of 175-176 ° C.

The quantities of the individual elements for the quinoxalic acid are in % By weight: C = 67.16%; N = 10.68%; H = 5.89%.

A mixture of 2.0 g of the quinoxalic acid obtained, 1.14 g of 1-isopentyl-2-methylindole (M, wherein R₈ = CH₃, R₉ = C₅H₁₁, R₁₀ = H) and 10 ml of acetic anhydride a temperature of about 50 ° C for about an hour stirred and then poured into ice and ammonia. The System is extracted twice with toluene and that Toluene evaporated after drying with sodium sulfate. The The residue is repeatedly recrystallized from toluene and has a melting point of 179-180 ° C. The product obtained is 1- (1-isopentyl-2-methylindole-3- yl) -1- (2-ethoxy-4-diethylaminophenyl) -1- [H] -3- [H] -furo- [3,4-b] quinoxalin-3-one; Elemental analysis in% by weight: C = 74.79; N = 9.71; H = 6.99. A solution to this gives up one with phenolic resin or Silton clay or one Combination of these two fabrics coated paper a deep blue color.

The 2- (2-ethoxy-4-diethylaminobenzoyl) -3-quinoxalic acid Example 8 can also be used with other units K, L, M, T to the invention listed in Table II Connections can be combined.  

Table II

Example 14 Preparation of 1,1-bis (2-chloro-4-diethylaminophenyl) - 1- [H] -3- [H] -furo [3,4-b] -quinoxalin-3-one.

First, m-chloro-N, N-diethylaniline (K, in which R₃ = Cl, R₄ = H, R₅ = R₆ = C₂H₅ and R₇ = H) with 2,3-quinoxalic anhydride (III, wherein R₁ = R₂ = H) combines to 2- (2-chloro-4-diethylaminobenzyl) -3-quinoxalic acid receive. For this, 0.2 mol of aniline and 0.2 mol anhydrous aluminum chloride to 250 ml tetrachloroethane added and stirred for 10 minutes. This system, which is initially cooled to 5 ° C becomes 0.06 mol 2,3-Quinoxalic anhydride added and the system is then stirred at 25 ° C. for 1 to 2 hours. The The mixture obtained is concentrated over 200 g of ice in 20 ml Poured hydrochloric acid and then steam distilled. The precipitate obtained is made several times Acetonitrile recrystallized and has a melting point from 193.5 to 194 ° C.

Elemental analysis in% by weight
calculated: C = 62.58; N = 10.95; H = 4.73; Cl = 9.24. found: C = 62.61; N = 11.00; H = 4.65; Cl = 9.25.

A mixture of 3.86 g of the quinoxalic acid obtained, 2.1 g m-chloro-N, N-diethylaniline (K, in which R₃ = Cl, R₄ = H, R₅ = R₆ = C₂H₅ and R₇ = H) and 25 ml of acetic anhydride in a melting tube for 16 hours to a temperature heated from 199 ° C. The mixture is then in ice and poured ammonia and extracted with toluene. The Toluene is dried using sodium sulfate, concentrated and using aluminum hydroxide of chloroform and then of ethyl acetate as  Chromatographed eluent. The solvent of the eluted fraction is evaporated and the material is recrystallized several times from chloroform-petroleum ether. The 1,1-bis (2-chloro-4-diethylaminophenyl) -1- obtained [H] -3- [H] -furo [3,4-b] quinoxalin-3-one has one Melting point from 214 to 216 ° C. A solution gives up a paper coated with Silton clay green-yellow color and on a phenolic resin coated Paper a green color.

Elemental analysis in% by weight
calculated: C = 65.58; N = 10.20; H = 5.50; Cl = 12.90. found: C = 65.66; N = 10.21; H = 5.43; Cl = 13.01.

The 2- (2-chloro-4-diethylaminobenzoyl) -3-quinoxalic acid according to Example 14, other units K, L, M to those listed in Table III below compounds of the invention can be combined.

Table III

Example 18 Preparation of 1- (1-ethyl-2-methylindol-3-yl) -1- (2- ethoxy-4-diethylaminophenyl) -1- [H] -3- [H] -furo [3,4-b] - quinoxalin-3-one.

First, 1-ethyl-2-methylindole (M, where R₈ = CH₃, R₉ = C₂H₅ and R₁₀ = H) with 2,3-quinoxalic anhydride (III, wherein R₁ = R₂ = H) linked to 2- (1-ethyl-2-methyl to obtain indol-3-yl) -3-quinoxalic anhydride. A Mixture of 0.02 mol of quinoxalic anhydride and 0.02 moles of indole are mixed for four hours Steam bath warmed. The hardened mass is cooled with an ammonia solution and extracted the ammonia solution washed with toluene. The ammonia solution washed in this way is then acidified to precipitate the reaction product. The precipitate is filtered, dried and recrystallized several times from acetonitrile. The received Product has a melting point of 139 to 190 ° C.

Elemental analysis in% by weight
calculated: C = 70.18; N = 11.69; H = 4.77. found: C = 69.89; N = 11.58; H = 4.79.

A mixture of 1.0 g of the quinoxalic acid obtained, 0.6 g of N, N-diethyl-m-phenetidine (K, in which R₃ = OC₂H₅, R₄ = H, R₅ = R₆ = C₂H₅, R₇ = H) and 7 ml acetic anhydride is heated to 55 ° C for 1½ hours, then Ice and ammonia are added, and then using Toluene extracted. After drying, the toluene is mixed with Evaporated sodium sulfate. The 1- (1-ethyl-2- methylindol-3-yl) -1- (2-ethoxy-4-diethylaminophenyl) -1- After recrystallization, [H] -3- [H] -furo [3,4-b] -quinoxalin-3-one has a melting point of acetonitrile  213.5-214.5 ° C and gives on one with phenolic resin or Silton clay or a combination of the two Fabrics coated paper a blue color.

The product obtained according to Example 18 corresponds to that Product of example 12.

2- (1-ethyl-2-methylindol-3-yl) -3-quinoxalic acid des Example 18 can also be used with other units K, L, M, T combined to further compounds according to the invention be (Table IV).

Table IV

Example 23 Preparation of 1,1-bis (2-methyl-4-diethylaminophenyl) - 6,7-dimethyl-1- [H] -3- [H] -furo [3,4-b] -quinoxalin-3-one.

First, N, N-diethyl-m-toluidine (K, where R₃ = CH₃, R₄ = H, R₅ = R₆ = C₂H₅, R₇ = H) with 6,7-dimethyl-2,3-quinoxalic anhydride (III, wherein R₁ = R₂ = CH₃) linked to 2- (2-methyl-4-diethylaminobenzoyl) -6,7-dimethyl-3-quinoxalic acid to obtain. A mixture of 0.1 moles of Toluene and 0.1 mole of anhydrous aluminum chloride stirred in 100 ml of tetrachloroethane. The mixture will cooled to less than 10 ° C and it becomes 0.02 mol of 2,3-quinoxalic anhydride added slowly. The Mixture is stirred for 2 hours, then in ice and poured concentrated hydrochloric acid and steam distilled. The distillate is made basic and filtered. The The filtrate obtained is dissolved in dilute hydrochloric acid and filtered again after adjusting the pH to 3.5. The filtrate obtained is dissolved in an ammonia solution and filtered again after adjusting the pH to 3.0. The dried residue is 2- (2-methyl-4-diethyl aminobenzoyl) -6,7-dimethyl-3-quinoxalic acid.

A mixture of 1.0 g of the quinoxalic acid obtained, 0.45 g of N, N-diethyl-m-toluidine (K, in which R₃ = CH₃, R₄ = H, R₅ = R₆ = C₂H₅, R₇ = H) and 10 ml of acetic anhydride rectified for an hour and poured into ice and ammonia. The system is extracted twice with toluene, dried in the toluene using sodium sulfate and then the toluene is evaporated. The residue is dissolved in chloroform and used of chloroform as an eluent on aluminum hydroxide chromatographed. The solvent of the eluted fraction is evaporated and the material is  three times from toluene-petroleum ether and once from toluene recrystallized. The solution of the 1,1-bis (2- methyl-4-diethylaminophenyl) -6,7-diethyl-1- [H] -3- [H] - furo [3,4-b] -quinoxalin-3-one gives on one with phenolic resin or siltonia or a combination thereof Both fabrics coated paper a green color.

The 2- (2-methyl-4-diethylaminobenzoyl) -6,7-dimethyl-3- Quinoxalic acid of Example 23 can also be used with others Units K, L, M, T to form further compounds according to the invention can be combined (Table V).

Table V

Example 28 Preparation of 1,1-bis (1,2,5-trimethylpyrr-3-yl) -6.7- dichloro-1- [H] -3- [H] -furo [3,4-b] -quinoxalin-3-one.

18.5 g of dihydroxysuccinic acid become a solution of 25.1 g of 4,5-dichloro-o-phenyldiamine in 220 ml each Water and ethanol added after stirring for five minutes acidified with hydrochloric acid and the reaction product 6,7-dichloro-2,3-quinoxalic acid filtered off.

A mixture of 0.6 g of the quinoxalic acid obtained and 0.6 g of 1,2,5-trimethylpyrrole (L, where R₈ = R₉ = CH₃) is dissolved in hydrochloric acid and 1,1-bis (1,2,5- trimethylpyrr-3-yl) -6,7-dichloro-1- [H] -3- [H] -furo [3,4-b] - quinoxalin-3-one, which is based on a phenolic resin coated paper gives an orange color.

Example 29

Likewise, a mixture of 0.6 g of the example 28 produced 6,7-dichloro-2,3-quinoxalic acid and 0.75 g of 1-ethyl-2-methylindole (M, wherein R₈ = CH₃, R₉ = C₂H₅) to 1,1-bis- (1-ethyl-2-methylindol-3-yl) -6,7-dichloro-1- [H] -3- [H] -furo [3,4-b] -quinoxalin-3-one, which on a purple paper coated with phenolic resin Color results.  

Example 30 Preparation of 1,1-bis (2-methyl-4-diethylaminophenyl) - 6,7-dimethyl-1- [H] -3- [H] -furo [3,4-b] -quinoxalin-3-one.

25 g of dihydroxysuccinic acid become boiling Solution of 25 g of 4,5-dimethyl-o-phenylenediamine in 500 ml Water added. This mixture makes hydrochloric acid gas passed through. The mixture is cooled and on solid product is separated by filtration. The separated material is dried, in 150 ml of acetic acid dissolved and rectified for 15 minutes. The System is cooled and by filtration is 6,7-dimethyl-2,3-quinoxaline anhydride with a decomposition point separated from 241 ° C.

A mixture of 0.6 g of the quinoxalic anhydride obtained and 0.9 g of N, N-diethyl-m-toluidine (K, wherein R₃ = CH₃, R₄ = H, R₅ = R₆ = C₂H₅, R₇ = H) are in 10 ml of acetic anhydride rectified for an hour, it will dilute ammonia added to the mixture with toluene extracted and the reaction product 1,1-bis (2-methyl- 4-diethylaminophenyl) -6,7-dimethyl-1- [H] -3- [H] -furo [3,4-b) -quinoxalin-3-one isolated. It results in one paper coated with phenolic resin a green color.

Example 31

The procedure according to Example 30 is repeated under Use of 0.6 g of that prepared according to Example 30 6,7-dimethyl-2,3-quinoxalic anhydride and 1.0 g N, N-diethyl-m-phenetidine (K, where R₃ = OC₂H₅, R₄ = H,  R₅ = R₆ = C₂H₅, R₇ = H). The reaction product is 1,1-bis (2- ethoxy-4-diethylaminophenyl) -6,7-dimethyl-1- [H] -3- [H] - furo [3,4-b] -quinoxalin-3-one and gives on one with Phenolic resin coated paper a green-blue color.

Other compounds made analogously are the examples 32 and 33 in Table VI.

Table VI

Claims (2)

1. Chromogenic furo [3,4-b] quinoxalin-3-ones of the general formula (I) wherein X is one of the groups K, L, M, T, W or Z, and Y is one of the groups K, L, M or T, wherein means and wherein R₁, R₂, R₃, R₄ and R₇ independently represent hydrogen, chlorine or a nitro, C₁-C₆-alkyl, C₁-C₆-alkoxy or di-C₁-C₆-alkylamino radical; R₅ and R₆ are hydrogen or a phenyl, benzyl or C₁-C₆ alkyl radical, provided that when R₅ or R₆ is a phenyl or benzyl radical the other group is hydrogen or a methyl radical; R₈ is hydrogen or a phenyl, C₁-C₆ alkyl or C₁-C₆ alkoxy radical; R₉ is hydrogen or a phenyl or C₁-C₆ alkyl radical; R₁₀ is hydrogen or a C₁-C₆ alkyl or C₁-C₆ alkoxy radical; R₁₁ is a C₁-C₆ alkoxy radical; and R₁₂ is hydrogen or a methyl or ethyl radical. 2. Use of the chromogenic quinoxaline compounds according to claim 1 as a color reagent in pressure sensitive Recording material.