DE1142981B - Process for the preparation of fluorubine - Google Patents

Description

GERMAN

PATENT OFFICE

B 59179 IV c / 22 e

REGISTRATION DAY: SEPTEMBER 1, 1960

NOTICE THE REGISTRATION AND ISSUE OF EDITORIAL: JANUARY 31, 1963

It is known that fluorubine (6,13-dihydro-5,6,7,12,13,14-hexazapentazene-I) and its substitution products, those in positions 1 to 4 and 8 to 11 low molecular weight alkyl radicals or halogens can carry

by reacting 2,3-dichloroquinoxaline with 2,3-diaminoquinoxaline (Ber. dtsch. former Ges., 36, p. 4048 [1903], and US Pat. No. 2,495,202). _ao

The yields of this process using excess 2,3-dichloroquinoxaline as a flux used, reach at best 65% of theory, calculated on the applied 2,3-diaminochinoxaline, and 45% of theory, calculated on the 2,3-dichloroquinoxaline used.

The 2,3-diaminoquinoxaline used in the above method can be obtained by treating 2,3-dichloroquinoxaline can be produced with alcoholic ammonia under pressure (J. former Soc., 1945, p. 622). However, this produces an impure 2,3-diaminochinoxaline, which can be used without further purification is not suitable for fluorubin production. It must be hydrochloride of byproducts, in particular of 2-amino-3-hydroxyquinoxaline, separated, whereby the yield of purified product is only 60% of theory, based on 2,3-dichloroquinoxaline. Will this diamine is then reacted with dichloroquinoxaline to form fluorubine, so one finally obtains the dye in a total yield of about 49% of theory, calculated on the total 2,3-dichloroquinoxaline required without taking into account the excess as flux used. If the fluorubine produced in this way is to be obtained in the required high purity, then you have to boil it with organic solvents such as dimethylformamide or N-methylpyrrolidone or the sulfate from its solution in concentrated sulfuric acid by adding water fractional fall. Both purification processes lead to further sensitive losses in yield, see above Process for the preparation of fluorubine

Applicant:

Aniline & Soda Factory in Baden

Corporation,

Ludwigshafen / Rhine

Dr. Werner Deuschel, Freiburg (Switzerland),

and Dr. Günther Riedel, Mannheim,

have been named as inventors

that finally only about 30 parts of pure fluorubine are obtained from 100 parts of 2,3-dichloroquinoxaline will.

In this purified form and using conventional methods, the fluorubine is finely divided brought, such as marrying or further falling from concentrated sulfuric acid, a strong color yellow pigment with excellent fastness properties.

It has now been found that fluorubine or its substitution products containing, for example, low molecular weight alkyl radicals and / or halogens in the 1- to 4- and 8- to 11-positions, if 2-amino-3-chloroquinoxaline or its in 5 -, 6-, 7- and / or 8-position corresponding substituted derivatives, optionally in the 0.5-to ten-fold amount by weight at the reaction temperature of liquid organic diluent, to temperatures of at least 140 ⁰ C, but not more than 300 ° C and, if necessary in Heated in the presence of agents that absorb hydrogen chloride.

The main advantage of the method according to the invention over the already known method consists in the use of only one starting substance, the 2-amino-3-chloroquinoxaline, that from 2,3-dichloroquinoxaline according to Haworth and Robinson, J. Chem. Soc., 1948, p. 777, or preferably in excellent yield and purity according to the method of the German Auslegeschrift 1 135 471 can be produced. The production of a pure fluorubine and the reproducibility the process is therefore only dependent on the purity of a starting substance,

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3 4

whereby the production of the dye is substantially based on yield of about 55% of theory

is simplified. The same applies if in 2,3-dichloroquinoxaline.

5- to 8-position substituted 2-amino-3-chloro- The 2-amino-3-chloroquinoxaline can, provided it

quinoxaline are implemented. according to the procedure of the German interpretative document One of the embodiments of the method 5 1 135 471 is produced, in contrast to the known

is to carefully process 2-amino-3-chloroquinoxaline, which starts from 2,3-diaminoquinoxaline,

above its melting point, for example longer can even be used without further purification.

Time to 15O ⁰ C or briefly to 200 ⁰ C, it is also possible, with the same success, to heat the hydro

wherein especially when heated to approximately 200 ⁰ C the Aminochlorverbindung for implementing chloride occurs a violent reaction. To use for the transfer of the 10.

Heat of reaction and to prevent losses Those given in the following examples however, by sublimation it is more advantageous that parts are parts by weight. Add organic solvents to the reaction mixture. For this, there are primarily aromatic hydrocarbons, halogen and / or aroma 15

Table nitro compounds and preferably dialkyl 200 parts of 2,3-dichloroquinoxaline are in

amides or mixtures of the mentioned solution 200 parts of N-methylpyrrolidone ^{heated to 140 0} C,

medium with boiling points of over 140 ⁰ C into consideration. Then dried ammonia gas is passed through

For example, dichlorobenzene and nitrobenzene are the solution. At a gas velocity of 501 Methylnapthalin, diphenyl, diphenyl ether, dimethyl _a o per hour and a gas consumption of 130 parts of

thylformamide, called N-methylpyrrolidone. The reaction is over after 3 hours. Man

preferably applies from about 1 to 5 times by weight the mixture allowed to cool, at 6O ⁰ C 400 parts

amount of this solvent, based on 2-amino-methanol, pours the reaction mixture into

3-chloroquinoxaline, and introduces the reaction with water, filtered off and washed with water. It a temperature of 150 to 250 ⁰ C from. In aroma- _a5 , 160 parts of 2-amino-3-chloroquinoxaline are in the form

However, in the presence of solvents, the reaction sets off pale yellowish crystals with a melting point of 141 to

one only at about 170 ⁰ C, and it is therefore advanta- received 143 ⁰ C. 100 parts of the 2-amino-

adhesive, at over 200 ⁰ C, e.g. at 210 to 220 ° C to 3-chloroquinoxaline in 150 parts of N-methyl

work. In boiling dimethylformamide, pyrrolidone alone was ^{heated to 180 °} C. for 5 hours. If without the addition of hydrochloric receiving ₃₀ N-Methylpyrrolidonmenge to the 2-, 3-, 4-, and

The elimination of hydrogen chloride is already 5 times higher than

at 150 to 155 ° C - albeit very slowly - the reaction time is correspondingly up to

take place. However, the reaction time can be increased to 10 hours. The mixture is left

Shorten from 8 hours to about 4 hours, when cool, suction off and wash with N-Methylman alkalis, e.g. B. sodium or potassium carbonate, ₃₅ pyrrolidone and methanol. 48 parts are obtained

clogs. The reaction time is also pro- fluorubine in the form of an olive green powder that

proportional to the dilution. So you need z. B. about 36O ⁰ C to melt and its hue by

in 1 to 1.5 times the amount by weight of N-methyl rub-out turns yellow.

pyrrolidone, based on Aminochlorverbindung, wherein the reaction product dissolves with violet red 200 ° C for about 3 to 4 hours and in ₄₀ 5 times the color in concentrated sulfuric acid. already 8 to 12 hours until the end of the conversion to a yellow pigment one dissolves the reaction. 48 parts of the above obtained crude olive Another advantage of the encryption Fluorubins invention at 20 to 3O ⁰ C in 1000 parts of 96 ° / ₀ hydrochloric driving is the possibility of the production of sulfuric acid, then allowed to cool under Fluorubins directly to the preparation of ₄₅ 200 parts of water run in, then dissolves the red-brown fluorubine sulfate separated from 2-amino-3-chloroquinoxaline in the same reaction again in the medium and, if desired, also in the same sulfuric acid, and the dye is added through the reaction vessel. For this purpose, by adding this solution to a mixture of ice, a solution of 2,3-dichloroquinoxaline in and an excess of 20% ammonia is passed. The approximately 1 to 1.5 times the amount by weight of N-methyl- ₅₀ yellow precipitate is filtered off with suction, washed with water pyrrolidone first at temperatures of approximately and then thoroughly with methanol. Man 140 to 160 ⁰ C as long as ammonia, until min- 44 parts receives a grünstichiggelben pigment least 95% of theory of 2-amino-3-chloroquinoxaline of excellent light fastness and resistance are originated, and then heating the reaction to solvents and plasticizers . With linseed oil mixture to about 180 to 200 ⁰ C, until the reaction "varnish rubbed in the usual way, results in the color of the fluorubine is complete. With this very substance a yellow letterpress ink, with which brilliant, simple and quickly executable processes are produced, yellow prints of excellent lightfastness, the dye is obtained in a yield of about 60%.
of theory, based on 2,3-dichloroquinoxaline. Example 2

According to the method according to the invention 6 ₀

Fluorubin produced can, after thorough 18 parts of 2-amino-3-chloroquinoxaline, produced as

wash with dimethylformamide or N-methyl- described in Example 1, and 10.8 parts of water-

pyrrolidone by a conventional grinding or precipitation-free sodium carbonate in 60 parts of di-

process are brought into fine distribution. Methylformamide is heated to boiling for 4 hours.

a plasticizer and solvent- _{resistant 65} is obtained. 7.5 parts of fluorubine are obtained in the form of yellow

Yellow pigment of excellent color purity. Made of crystals.

Parts of the dichloro compound are obtained for conversion into a fine pigment form

Parts of pure pigment, which corresponds to an overall procedure as described in Example 1.

Example 3

100 parts of 2-amino-3-chloroquinoxaline, prepared according to Example 1, paragraph 1, are heated to boiling temperature in 200 parts of trichlorobenzene for 7 hours. The initially stormy evolution of hydrogen chloride is practically over after this period of time. After the product has been filtered off with suction and washed with hot trichlorobenzene and methanol, the filter residue is heated for a short time with 200 parts of boiling dimethylformamide. 67.5 parts of a red-brown powder are obtained, from which 44 parts of pure fluorubine are obtained by treatment with concentrated sulfuric acid in the manner described in Example 1.

The conversion of 2-amino-3-chloroquinoxaline described in this example can be equally successful also, for example, in nitrobenzene, dichlorobenzene, chloronapthalene or diphenyl diphenyloxide mixtures be performed.

Example 4

1200 parts of 2,3-dichloroquinoxaline are heated in 1,800 parts of N-methylpyrrolidone at 14O ⁰ C, then passing a 450 parts of dried ammonia gas within about 3.5 hours. The reaction is complete when a sample dissolves clearly in 2N hydrochloric acid. The temperature is then increased to 180 ° C. and the reaction mixture is heated to this temperature for 5 hours. After cooling, the precipitate is filtered off with suction, washed with a little N-methylpyrrolidone, then with water and methanol and the filter residue is treated for a short time with 2000 parts of dimethylformamide. 520 parts of an olive-green shimmering crystal powder with the same properties as described under Example 1 are obtained, the content of pure fluorubine of which is at least 480 parts.

Example 5

40

86 parts of 2-amino-3,6 (7?) - dichloroquinoxaline, prepared from 2,3,6-trichloroquinoxaline by the process described in Example 1, paragraph 1, are heated in 170 parts of N-methylpyrrolidone to 200 ° for 4 hours C. This gives 43 parts of 2,9 (10?) - Dichlorfluorubin in the form of an olive-green powder which is not melted at 400 ⁰ C and its color is yellow by reaming. The product dissolves in concentrated sulfuric acid with a violet color and, after the above-described reprecipitation, leads to a yellow pigment of good color strength.

Example 6

The mixture is heated 36 parts of 2-amino-3-chloroquinoxaline in an oil bath at 220 ⁰ C (bath temperature) and the reaction lasts 30 minutes at this temperature. The initial reaction is violent and yellowish mists appear. After cooling, the residue is pulverized, boiled with 2N hydrochloric acid and dimethylformamide, washed thoroughly with methanol and dried. 15.4 parts of a brownish-tinged yellow powder are obtained which, as indicated in Example 1, can be converted into a yellow pigment.

Example 7

107 parts of 2-amino-3-chloro-6-methylquinoxaline from 2,3-dichloro-6-methylquinoxaline according to the information in Example 1, paragraph 1, are in Parts of N-methylpyrrolidone heated to 200 ° C for 6 hours. 49 parts of 2,9-dimethylfluorubine are obtained in the form of olive green crystals. After falling over, as described in Example 1, a yellow pigment is obtained with very high color strength.

Claims (4)

PATENT CLAIMS: 1. Process for the production of fluorubine or its substitution products, which in 1- up to 4- and 8- to 11-position can also contain low molecular weight alkyl radicals and / or halogen, characterized in that 2-amino-3-chloroquinoxaline or its in the 5-, 6-, 7- and / or 8-position correspondingly substituted derivatives thereof, optionally in the 0.5 to ten-fold amount by weight at the reaction temperature of liquid organic diluent, to temperatures of at least 140 ⁰ C, but not exceeding 300 ⁰ C and, if necessary, receiving in the presence of hydrochloric means heated. 2. The method according to claim 1, characterized in that the liquid organic diluent at the reaction temperature Dialkylamides, N-alkyllactams, aromatics of the benzene and naphthalene series or mixtures of the solvents mentioned. 3. The method according to claim 1 and 2, characterized in that as N-alkyl lactams N-methyl, N-ethylpyrrolidone- (2), N-methyl- or N-ethylpiperidone- (2) in 1 to 5 times Amount by weight are used and optionally that in these solvents - if desired in the same reaction vessel - 2-amino-3-chloroquinoxaline produced from 2,3-dichloroquinoxaline and ammonia at 120 to 160 ° C is used. 4. The method according to claim 1 and 2, characterized in that the absorbing hydrogen chloride Medium alkali or alkaline earth carbonate can be used. 35 55 When the application was announced, a coloring table with explanations was laid out. 309 507/307 1.63