DE2259409C2 - Chromogenic furo [3,4-b] pyridin-7-ones and pyrazin-5-ones - Google Patents

Description

is.

2. Use of a chromogenic compound according to claim 1 as a chromogenic color former for pressure-sensitive products Recording material.

Resistance and high coloring power

The table below shows the AE values before and after exposure and the color stability (in%) of markings obtained with compounds according to the invention and with the best previously known compounds of similar color and structure. The AE value (MacAdams intensity) represents an integration of all changes in hue, saturation, intensity and gray value. The higher the values for AE before exposure and AE after exposure (after 50 hours of exposure to a daylight fluorescent lamp), the better the initial color intensity (tinting power) and the higher the color fastness. The quotient

^{x! 00} ( ^{percentage of} remaining color intensity) ^ _Q

is a measure of color fastness. Higher percentages mean higher color fastness. As the table shows, the compounds according to the invention have better color stability than that known compounds of the same color used for comparison.

To produce the markings, 1 ml of a solution of 0.1 g of the chromogenic to be tested Compound in 100 ml of benzene with 1 ml of a solution of 1 g of p-phenyl-phenol-formaldehyde resin in 100 ml of benzene mixed. The colored solution obtained was diluted to 10 ml with benzene. 0.5 ml of this dye-resin solution were dropped onto No. 1 Whatman filter paper and then air dried for several hours.

Connection Color Before After%

Exposure exposure AE ΔΕ

7- (1,2-Dimethyl-indol-3-yI) -7- (4-dimethylaminophenyl) - blue 29.5 22.5 76

2-oxo-2,7-dihydro-benzo [3,4] furan

(US-PS 34 91 116) *

7- (1-ethyl-2-methyl-indol-3-yl) -7- (2-ethoxy blue 31.8 25.2 79

4-dimethylaminophenyl) tetrachloro-2-oxo-2,7-dihydro- '

benzo [3.4] furan

(US-PS 34 91 116)

7- (1-Ethyl-2-methyl-indol-3-yl) -7- (4-dimethylamino blue 31.3 23.6 75

phenyl) -2-oxo-2,7-dihydro-benzc [3,4] furan

(US-PS 34 91 116)

7- (1,2-dimethyl-indol-3-yl) -7- (l-ethyl- reddish- 48.0 33.4 70

carbazol-4-yl) -2-oxo-2,7-dihydro-benzo [3,4] furan purple

(US-PS 34 91 111)

7,7-bis (1,2-dimethyl-indol-3-yl) -dimethylamino- reddish-33.4 17.7 53

2-oxo-2,7-dihydro-benzo [3,4] furan purple

(US-PS 34 91 111)

7,7-bis (2-phenyl-indol-3-yl) -2-oxo-purple 9.8 6.6 67

2,7-dihydro-benzo [3,4] furan

(US-PS 35 09 173)

7,7-bis (1-ethyl-2-methyl-indol-3-yl) -2-oxo-reddish 44.1 36.4 83

2,7-dihydro-benzo [3,4] furan purple

(US-PS 35 09 173)

Compounds according to the invention

Color Before After ° / o

Exposure: exposure AE ΔΕ

Y = C

X, = X ₂ = 1,2-dimethyl-indoI-3-y]

Y = C

X, = χ, = 1-ethyl-2-methy] -indoI-3-yI

Y = C

X ₁ = X ₂ = 1-butyl-2-methyl-indol-3-yl

Y = C

Xi = 1-ethyl-2-methyl-indol-3-yl X2 = 2-methyl-4-diethylaminophenyl

Y = C

Ι = l-ethyl-2-methyl-indoI-3-yl X2 = 2-ethoxy-4-diethylaminophenyl

Y = N Xi = 1-ethyl-1-methyl-indol-S-yl X2 = 2-ethoxy-4-diethylaminophenyl

Y = N Xi = 1-ethyl-1-methyl-indol-S-yl X2 = 1-methyl-2-phenyl-indol-3-yl

Y = N

Xi = X ₂ = 2-ethoxy-4-diethylaminophenyl

reddish- 34.8 29.7 purple purple 42.0 37.6 purple 34.8 29.7

blue

purple

blue green

27.3

39.0

32.8

25.6

37.9

22.6

34.3

27.4

21.2

27.8

The invention is illustrated below with the aid of examples for the preparation of compounds according to the invention described in more detail. Other compounds of the present invention can be used in a similar manner appropriately substituted starting materials are produced.

Unless otherwise stated, the resin in the examples consists of 80 parts by weight of tertiary p-butylphenol and 20 parts by weight of p-chlorophenol and the clay is Silton.

example 1

In this example the 7- (1-ethyl-2-methylindol-3-yI) -7- (2-ethoxy-4-diethylaminophenyl) -5,7-dihydrofuro [3,4-b] pyrazine-5 compound made with the following formula:

N (C ₂ H ₅ ),

A mixture of 4.65 g (15 mmol) of (1-ethyl-2-methyl-indol-3-yl) -2-carboxy-pyrazin-3-yl-ketone, 2.9 kg (15 mmol) of m-ethoxydiethylaminobenzene and 21 cm ^{3 of} acetic anhydride were heated to about 120 to 130 ^° C. for 15 minutes. The mixture was poured into ice and ammonia and ^{extracted with 500 cm 3 of} benzene and dried (^ 2SO ₄ ). The solvent was evaporated and the remaining oil was triturated with petroleum ether. 4.0 g (55%) of an amorphous solid were obtained, which gave a single point on thin film chromatography. A benzene solution of this material gave a purple color on a clay-coated sheet and a blue color on a resin-coated sheet.

The above ketonic acid has also been substituted with one corresponding to the radical X of the following formula ! ndol or aniline (a few milligrams) in the presence of a few drops of acetic anhydride for reaction brought. After adding water and ammonia, the mixture was extracted with benzene and applied to paper coated with resin or clay. The colors obtained are from the can be seen in the following table.

C ₂ H

C = O

colour
resin

Clay

1-methyl-1-phenyl-indol-β-yl
2-methyl-4-diethylaminophenyl

purple
green

purple
blue

Example 2

This example uses the 7,7-bis (1-methyl-2-phenyIindol-3-yl) -5,7-dihydrofuro [3,4-b] pyrazine-5 compound manufactured using the following formula:

There are several milligrams each of 2,3-pyrazine dicarboxylic anhydride and 1-methyl-2-phenyl-indole and reflux three drops of acetic anhydride for one minute. The mixture was cooled with Treated dilute ammonia and extracted with benzene. The benzene solution gave upon contact with a Resin or clay sensitized sheet a purple color.

Similarly, others have been substituted in the meta position in accordance with the radical X of the following formula Anilines and indoles with 2,3-pyrazine-dicarboxylic acid anhydride reacted and in the above manner Treated a benzene solution of these compounds on a resin or clay coated paper applied, the colors given in the table below are obtained.

colour
resin

Clay

2-ethoxy-4-diethylamino-pheny] 2-Methyi-4-diethylaminophenyl 1-ethyl ^ -methyl-indoI-S-yl

green green green green purple purple

Example 3

In this example the 7- (1-ethyl-2-methylindol-3-yl) -7- (1-methyl-2-phenylindol-3-yl) -5,7-dihydrofuro [3,4-b] pyridine -5 connection made with the following formula:

C ₂ H

A mixture of 3.0 g (14.2 mmol) (1-ethyl-2-methyl-indol-3-yl) - (2-carboxy-pyridin-3-y!) - ketone, 4.3 g (14 , 2 mmol) of 1-methyl-2-phenylindole and 15 cm ^{3 of} acetic anhydride were refluxed for 5 minutes and poured into ice and ammonia and extracted twice with benzene. The benzene was washed with water and dried. After evaporation, 4.7 g of the material (68%) with a melting point of 240 to 241 ° C were obtained. A benzene solution of this material gives a purple color when applied to a sheet of paper sensitized with resin or clay.

The above keto acid was also reacted with m-methyldiethylaminobenzene by some Milligrams of these compounds were warmed with a few drops of acetic anhydride, followed by water and ammonia was diluted and the reaction mixture was extracted with benzene. The benzene layer was with Washed with water and applied to paper coated with resin or clay. It turned a blue color obtain.

Example 4

In this example the 7,7- (1,2-dimethylindol-3-yl) -5,7-dihydrofuro [3,4-b] pyridine-5-compound with the prepared using the following formula:

C = O

CH

CH ₃

CH ₃

A mixture of 1.5 g (10 mmol) of 2,3-pyridine-dicarboxylic acid anhydride, 3.64 g (25 mmol) of 1,2-dimethylindole and 10 cm ^{3 of} acetic anhydride was refluxed for half an hour and in ice and one Poured 5% sodium bicarbonate solution. The aqueous layer (pH 8) was extracted with benzene, and the benzene layer was washed with water and dried (sodium sulfate). After evaporating the benzene and washing the residue with petroleum ether, 1.9 g (22%) of crystalline material were obtained. Thin layer chromatography of this material gave two spots indicating that an isomeric mixture was obtained. A solution of this material gave a light purple color to the touch of both resin-coated and clay-coated paper sheets.

After recrystallization and chromatography, a single isomer was obtained with a melting point of 257.5 to 257.8 ° C.

The above anhydride was also given a few milligrams corresponding to the remainder X of the following Formula of substituted indoles in the presence of a few drops of acetic anhydride for one minute Brought reaction. The mixture was diluted with water and ammonia was added. The reaction mixture was then extracted with benzene and the benzene was washed with water. When applying From this solution on paper sensitized with resin or clay, those of the following table were obtained apparent colors.

C = O

colour
resin

Clay

1-Ethyl ^ -methyl-indol-S-yl 1-methyl-2-phenyl-indol-3-yI

red-purple
purple

red-purple
purple

The ketones of Examples 1 and 3 can be prepared in that 2,3-pyrazine-dicarhonic acid anhydride or 2,3-pyridine-dicarboxylic acid anhydride can be mixed with l-ethyl-2-methylindole in equimolar amounts and that the mixture is heated in a steam bath for at least 12 hours. The reaction mixture is cooled, extracted with dilute ammonia and filtered. The pH of the filtrate is adjusted to 4 to 4.4 adjusted and the resulting precipitate is filtered again and recrystallized from alcohol.

Claims (1)

Patent claims:
1. Furo [3,4-b] pyridin-7-ones and -pyrazin-5-ones of the general formula where Y is a carbon or nitrogen atom and Xi and X _{2 are} one of the following groups:
R ₂ Γητ The chromogenic furo [3,4-b] pyridin-7-ones and pyrazin-5-ones according to the invention are essentially colorless solids, which are colorless in solution, but in a reaction contact with an acidic substance into one pass dark colored state. When used in mark-forming systems, a mark is made in the desired areas a carrier web or a carrier sheet caused by a local reaction contact between the chromogenic substance and the acidic substance is brought about on or in the web or the leaf. Of the chromogenic substance can be applied to the carrier sheet or already be present in it. By the reaction contact, a dark color is achieved in the area to be marked. Pressure-sensitive, mark-forming systems contain the color-forming components on and / or in one or more carrier sheets, wherein the color former and the acidic substance by means of a pressure breakable material are separated from each other. When all the components are on a single sheet are located, one speaks of an "autogenously reactive" recording material. Are the color-forming ones Components arranged on separate sheets of paper are referred to as a "transmission system". Multiple carbon copy systems can be made by laying sheets on top of each other Have a receiving layer on the top and a transfer layer on their underside. The most commonly used carbonless material is a solution of basic chromogenic substances, for example phthalides, pyromellitides and fluorans, enclosed in microscopic capsules that are as a layer on one side of a transfer sheet while the adjacent side of the receiver sheet with a Lewis acid; d. H. with an electron acceptor, is sensitized. It's a great number of reagents of the Lewis acid type known to be used in conjunction with basic chromogens can be. The most common are acidic clays such as attapulgite, Silton clay, zeolite, bentonite, halloysite, Kaolin and silicon dioxide. However, acidic reacting polymeric substances are also used either alone or in combination with acidic clays. Examples of such polymeric substances are phenolic polymers, such as phenol-formaldehyde and phenol-acetylene polymers, maleic acid-rosin, partially or fully hydrolyzed styrene-maleic anhydride copolymers, carboxy-polymethylene and partially or fully hydrolyzed vinyl methyl ether maleic anhydride copolymers and mixtures of these substances. A large number of such acidic polymers as well as solvents for these and for the chromogenic substances are in DE-PS 17 25 550 described. The markings produced with the chromogenic compounds according to the invention have a large one | I. Ri is an alkyl radical with 1 to 4 carbon atoms, R _{2 is} an alkyl radical having 1 to 4 carbon atoms or an alkoxy radical having 1 to 4 carbon atoms and R3 is an alkyl radical with 1 to 4 carbon atoms or a phenyl radical