DE1644613C - Process for the production of vat dyes - Google Patents

Description

It was found fifjß mfin Küpen fortotolTo Φγ • ftll |? Ni ^e in ^e n Foml

o - c c == o

(2)

wherein R _{1 is} a hydrogen or an optionally substituted alkyl or aryl group, R _{2 is} a hydrogen or chlorine atom or an alkoxy or benzoylamino group and A is an optionally substituted arylene radical, can be prepared by anthrimides of the general formula

^R.

I.
N

O = C C- = O

wherein R _1, R ₂ and Λ have, preferably, heated alone or in a mixture with inert salts to about 300 to about 400 ⁰ C, to about 340 to about 370 ° C the meanings given above.

In detail, one can proceed in such a way that one uses the anthrimides serving as starting compounds Finely ground in a suitable vessel and spread in a thin layer and in an electrical Oven heated to the above-mentioned temperature ranges until the cleavage of the Hydrogen chloride has ended. After cooling, the dye can be obtained in practically quantitative yield isolate in very pure form.

With a view to technically efficient implementation of the process and simple isolation of the dye, however, it is expedient to proceed in this way. that m.in the finely ground anthrimide with the approximately 3 to 10 times the amount of an indifferent, water-soluble one Sal / es mixes as a carrier and in one electrically heated vessel with constant mixing the contents of the vessel are heated to the temperatures indicated above until the elimination of the hydrogen chloride is finished. After cooling, the contents of the vessel are poured into water, the salt is dissolved out, the dye is nitrated, washed with water and dried. Hr is obtained in a practically quantitative yield in a very pure form.

You can also make the process continuous, by using the anthrimide salt mixture a dosing device into a suitable, electrically heated pipe with an internal screw and the mixture slowly through the heated teeth promotes the dye-salt mixture emerging at the end of the pipe is worked up as described above.

As indifferent salts, for example, alkali halides, such as sodium chloride or potassium chloride, and also alkali sulfates, such as sodium sulfate or (3) 60 potassium sulfate.

According to the method, the ring closure takes place in the absence of condensing agents. The addition of condensation agents. especially alkaline even has a detrimental effect on the bulge and purity of the dyes obtainable according to the process out. This circumstance must be regarded as surprising and unforeseeable, than one used for ring closure reactions of this type

Increase in yield and recovery

purer product release agent

(see that in, the German patent specification I ISS 231

procedure described),

The method according to the invention possesses opposite the following essential advantages to the one described in the German patent specification I ISS 231:

1, The yield is practically quantitative and lies compared to the method described there by an average of 10 to 15% higher,

2. The ring closure takes place without the use of acid amides or high-boiling solvents, their regeneration, combined with the resulting loss, the procedure very expensive,

V The isolation takes place in the simplest possible catfish, while with the condensation in Solvent the dye must be isolated from this, which is only possible with great effort is.

4. The scope of the equipment required is comparatively small compared to the scope of the equipment which is required for the preparation of the dyes in a high-boiling solvent.
The method according to the invention has the following technical progress compared to the method known from French patent specification 1,413,400. Working without solvents eliminates the need for special equipment, which may also have to be explosion-proof, as well as cooling and closed filter devices.

In addition, the working method using solvents, as described in the French Patent is described, the following disadvantages, which the method according to the invention does not have. The solvent used can be recovered because it is heavily diluted with water. sensibly only take place by extraction, with the phenol split off during the reaction as well with accrues. This in turn requires a subsequent fractional distillation.

The same applies to the ratio of starting compounds used in the process according to the invention to the aids much cheaper. It ranges from 1: 0 (example 4) to 1:12 (example 2). while it is at the mode of operation according to the French patent specification is 1:23.

Example I.

In an open vessel equipped with a powerful stirrer, a mixture of 270 parts by weight of sodium chloride and 30 parts by weight of Anthrimi'is of the formula

untr heated with slow stirring to 330 to 35Q ⁰ C and kept at this temperature for 30 to 60 minutes. After cooling, the contents of the barrel are stirred into water, the dye after dissolving the sodium

qhlorids isolated, washed with water and dried Per dye obtained in almost quantitative yield gives a on cellulose fiber ^ a ■ bliv coloration of the same shade and purity as the pach the procedure of the German patent specification

ro j 188 231, Example I, dye made, used the same amount is used in place of the sodium chloride Potassium chloride, sodium sulfate or potassium sulfate, this leads to the same result,

Example 2

In a heatable cylindrical tube with a screw at the edge, which allows the at one end of the Conveying powdery material dosed into the pipe through a heated zone to the other end of the pipe, becomes a mixture of 100 parts by weight of the anthrimide of the formula

and 1200 parts by weight of sodium chloride are metered in. The bracing of the pipe is adjusted so that the Dosed material quickly reached a temperature of 350 to 380 C when passing through the pipe.

The speed of the screw is adjusted so that the heated material remains hot at 350 to 380 C for as long as it is necessary to split off the hydrogen chloride. which takes about 1/2 hour. The material, which has cooled down a little in the back of the pipe, falls while still hot into a vessel filled with water and stirred. The sodium chloride goes into solution. The dye is then isolated.
The yield of dye is practically quantitative.

Pefspie. 1 3

Yer-wencje |: rr ^ n an Ste]] e c | er) m p given fyfiscjipg ejne MJiJcliHTig 'MS 50

tii c | es Antlinmitis cjer Forme)

Example 4

30 pieces of qewiolite ae me a b | eoh in thinner t aHsgebrei | .e ^ n Anthrimids of the formula

-CO-HN

and 500 parts by weight of sodium chloride and if the rest of the procedure is as described there, an excellent one is obtained Yield a yellowish green dye which is similar in color and purity to the im Example 4 of German Patent 1,188,231 is similar to the dye described.

When using the anthrimide of the formula

^{are heated to 350 °} C. for 30 minutes in an electrically heated oven. After brief melting, the previously brown anthrimide is converted into a dye that solidifies in blackish crystals, with elimination of hydrogen chloride. The dye obtained in excellent yield is sufficiently pure. It can be used directly for the production of coloring powders or printing dough without further cleaning.

Example 5
When using an anthrimide of the formula

^ -

-HN

one gets a clearly good yield in a good yield hi; iustit: higercn. olive green vat dye.

for ring closure according to the examples 1, 2 or 4 The same dye is obtained as described in Example 5 of the German patent 1 188 231 is described.

Claims (1)

Claim Process for the production of vat dyes the general formula or O = * (D (2) wherein R _{1 is} a hydrogen atom or an optionally substituted alkyl or aryl group, R _{2 is} a hydrogen or chlorine atom or an alkoxy or benzoylamino group and A is Gegeberierifalis substituted Afyierirest means? thereby g e lcefi ri ze ί ö h η e t that rriari Anthrimides of the general formula wherein R ₁₄ R ₂ and A have the meanings given above, alone barren for preferably heated in a mixture with inert salts to about? 00 to about 400 ⁰ C to about 340 BiV about 370 ⁰ C. 209 618/19; 2256