DE81264C - - Google Patents

Description

IMPERIAL

PATENT OFFICE.

Dyes.

It has been shown that when ammonia acts on the rhodamines, they become dibasic ο - carboxylic acids (especially phthalic acid and succinic acid) colorless more nitrogen-rich compounds arise, which when treated with dehydrating agents pass into new dyes.

The mentioned action products differ from the corresponding (anhydric) Rhodamine bases with regard to their composition, because one oxygen atom the rhodamine base is replaced here by the imide group.

So has z. B. the product obtained from Tetraäthylphtalsäurerhodamih and ammonia the empirical composition

C ₂₀ H ₁₀ O ₂ (NHJK ₂ (C ₂ H ₅ I.

5/4

(Tetraethylrhodaminimide).

The new compounds become higher when heated with dilute acids Temperature (some even when boiling with 5% sulfuric acid) back to the converted back to original rhodamine. They are not colored in themselves, but they can - partly by salt formation, partly by other transformations - easily into dyes to pass over, which still have the character of the rhodamines. From this can it was concluded that it was not the pyranium oxygen, but an oxygen atom of the anhydrous

Group \ fß /

is replaced by imide.

So z. B. the constitution of the derivative of Tetraäthylphtalsäurerhodamins

HY ₂ N

y N (C ₂ H ₅ ),

to be attributed.

The action of dehydrating agents on these rhodamine imides easily and smooth dyes differ from the original rhodamines in that a bluer shade of color, but otherwise behave very similarly to them. They are thought to be nitriles their relation to the original rhodamines can be seen in the following constitutional formulas is illustrated:

-.N (C ₂ HJ ₂ Cl

Rhodamine

N (C ₂ HJ ₃ Cl

C ₆ H ₁ -CN

New dye.

Example I.

Tetraäthylphtalsäurerhodamin (Rhodamine B extra) is in five times the amount of alcohol dissolved and ammonia introduced into the solution in the cold until saturation. then it is heated in an autoclave for about ι o hours to approx. 180 ° C. After cooling down the greater part of the reaction product is in coarse, little colored crystals eliminated. These are collected and washed with a little cold alcohol. By Recrystallization from dilute alcohol gives colorless crystals, which at 229 ° C. melt and have the composition discussed above.

The imide thus obtained dissolves in concentrated sulfuric acid with a yellow color. In glacial acetic acid it is easily soluble, especially when heated, with its intensely red color the rhodamine, which disappears again on evaporation of the glacial acetic acid. With Water diluted glacial acetic acid solution can be used for dyeing; for example becomes tannic Cotton is dyed a bit more bluish as a result, as with the original dye (rhodamine B extra); however, the coloration is not as alkaline as that obtained with rhodamine.

In the above example, if the tetraethylphthalic acid rhodamine is replaced by other rhodamines phthalic acid or succinic acid, e.g. B. by tetramethylphthalic acid rhodamine, tetramethyl succinic acid rhodamine, Diethyl-, di-o- or -p-tolyl-phthalic acid rhodamine, is obtained New substances behaving quite analogously, which are likewise transformed into new, partly valuable Rhodamine dyes can be transferred.

Example II.

5 parts of the rhodamine imide prepared according to Example I are heated with 2 parts of phosphorus oxychloride (in the presence or absence of a diluent such as toluene) in a water bath for about 2 hours. The reaction product (possibly after removing the diluent used) is dissolved in boiling water, and common salt is added to the solution, filtered if necessary. On cooling, the new dye crystallizes from green glossy leaves that are readily soluble in ater W ^T.

From the aqueous solution, caustic soda, the color base falls in reddish flakes; their analysis gave the same percentage composition as the original ammonia product.

The new dye dyes wool and silk violet-red, tannic cotton with a strong bluish tinge with intense fluorescence.

Instead of heating the ammonia product with phosphorus oxychloride, you can do the same melt together with zinc chloride; other dehydrating agents have a similar effect, such as Phosphorus pentachloride, phosphorus pentoxide, fuming sulfuric acid, etc.

If one replaces the product of the action of ammonia on the tetraethylrhodamine in the above examples by the corresponding product from tetramethylrhodamine, a very similar dye is obtained. Also from the In contrast to the starting material, diethylrhodamine has a good dye derived from it Solubility and dyes tannin cotton in beautiful, far more yellow tones than tetraethylrhodamine.

Claims (2)

Patent Claims: ι. Process for converting the rhodamines of dibasic o-carboxylic acids into nitrogen-rich ones Products consisting in the action of ammonia on the rhodamines mentioned at a higher temperature läfst and the rhodamine imides thus obtained by treatment with dehydrating Converts funds into new dyes. 2. The special embodiments of the method protected by claim 1 therein consisting of allowing ammonia to act on tetramethyl-, tetraethyl- or diethylrhodamine at a higher temperature and the rhodamine imides thus obtained with dehydrating agents such as phosphorus oxychloride or zinc chloride.