DE2242784A1 - PROCESS FOR THE PREPARATION OF 2ARYL-V-TRIAZOLES - Google Patents

Description

Bayer Aktiengesellschaft 2242784

Leverkusen, Bayerwerk

Central area

Patents, trademarks and licenses

jo / pt 2 Q ₁ :.: "). 1972

Process for the preparation of 2-aryl-v-triazoles

The present process is concerned with a synthesis of 2-aryl-v-triazoles by cyclizing CÄ -oximinohydrazones with urea in water, alcohol or alcohol / water mixtures.

British patent 1,215,507 has made known a process in which oximinoarylhydrazones or their O-acyl compounds are cyclized in a urea melt at relatively high temperatures Achieve yields, but these yields decrease considerably, especially in the case of compounds containing sulfonic acid groups, i.e. water-soluble compounds, if one tried to carry out this method on an industrial scale.

The major disadvantage of this method is in particular that _for the arising large amounts have to be absorbed to hydrocyanic acid, ammonia, exhaust gases in complex absorption systems.

It has now been found, surprisingly, that 2 "aryl-v-triazoles while avoiding the disadvantages mentioned above in very good

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Yields obtained if one o ^ -oximinoarylhydrazones of the general » my formula

Ar

.N = C-R

NH '

HO-N = C-R,

(D

in which
Ar

for an aromatic-carbocyclic or aromatic heterocyclic radical stands,

an aliphatic or aromatic radical,

Hydrogen, an aliphatic or aromatic radical and

the numbers 1 or 2 mean

with at least 1 equivalent of urea in water, with water converts miscible polar solvents or mixtures thereof.

Suitable aromatic-carbocyclic and aromatic-heterocyclic Residues are those of the benzene, naphthalene, diphenyl, diphenylmethane, diphenylethane, stilbene, tolane, pyridine, Triazole, imidazole, pyrazole, coumarin or carbostyril series, which may optionally contain further substituents, for example halogen atoms, alkyl, alkoxy, hydroxy, cyano, carboxy, carbonamldo, sulfo, alkylcarbonyl, alkoxycarbonyl, Alkylsulfonyl or arylsulfonyl groups, with alkyl and alkoxy groups are preferably to be understood as having 1-4 carbon atoms.

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INSPECTED

Suitable radicals R are, for example, alkyl radicals with 1-4 carbon atoms, which are optionally replaced by halogen atoms, OH, carboxy or C. - Cj. -Alk oxy groups can be further substituted, as well as phenyl radicals optionally substituted by halogen atoms, C ^ - Cl - alkyl or C, - C ₂ , - alkoxy groups. Suitable radicals Rp are hydrogen and the groups mentioned under R-.

OL-oximinohydrazones of the formulas are particularly preferred

II

wherein

R ₁ and R _{2 have} the abovementioned meaning, R-, for a carbocyclic or heterocyclic radical and

X stands for 0 or NR ₂₁ ,

wherein

R ₂ ^ for an optionally substituted alkyl radical with

1-4 carbon atoms and

N-

H OH

CH = CH

SO H HO, S

III

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ORIGINAL JNSPECTED

wherein If

R. and R _{2 have} the abovementioned meaning and Rc represents hydrogen, an acylated amino group which

group

wherein Y is N or CH and Z is N, CR ₁ or OH or the group

- NC — R ₁

k I ^x

CR ₅

^H0 /

R. and R _{2 have} the abovementioned meaning.

Suitable radicals R are those of the benzene-i pyrazole, 1 ₁ 2,3- ■ TrIaBOl- (I) and the 1,2,4-triaeol series,

Most of the cL -oximinohydrazones of the formulas I, II and III required for the process according to the invention are known, for example from German Offenlegungsschriften 1 670 969, 1 670 999, 1 594 845, 1 962 553, 2 0-7 854, 2 040 and 1 917 740, and from British patents 1 215 507, 1 108 416, 1 154 995 and 1 155 229 or can in a manner known per se , for example by condensation of corresponding aryl

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0 9 8 1 1/1 1 9 0 ORIGINAL INSPECTED

hydrazines with G ^ - oximinoketones of the formula R ₁ -CO- CR ₂ = NOH

R ₁ and R ₂ are as defined at the beginning.

In Verg] I ß to the previously known Triazolringschlüssen reaction is carried out in the inventive process at relatively low temperatures, namely between 90 and IjJO ⁰ C.

Water-miscible solvents are, for example, amides, such as dimethylformamide, N-methylpyrrolidone and hexamethylphosphoric triamide; Dimethyl sulfoxide and especially alcohols.

Suitable water-miscible alcohols are those with a boiling point of ^ -90 ⁰ C, especially polyhydric alcohols and their partial alkyl ethers ^ z. B ₀ : Ethylene glycol, diethylene glycol, glycerol and butylene glycol and their monoalkyl ethers, for example monomethyl and monoethyl ethers. If δ-oximinoarylhydrazones of the formula I which contain water-solubilizing groups are used as the starting material, alcohol / water mixtures and, above all, pure water are particularly suitable.

The addition of a base is also often · an advantage » Suitable basic substances are, for example, alkali metal hydroxides, alkali metal carbonates, pyridine * quinoline and dimethyl · = aniline.

In the practical implementation of the process according to the invention, it is expedient to proceed in such a way that the OL-Oximinoary! Hydrazones of the formula I dissolves or suspends in twice to 10 times the amount of the abovementioned solvents

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O O / '"> '7 ο /

and at least 1 mol of urea is added with stirring, the reaction temperature is set and after the cyclization has ended the reaction mixture worked up in a customary manner, for example by cooling and crystallization, if appropriate by prior concentration or by diluting with water and salting out. Processing is particularly easy when using water-soluble, i.e. compounds of the formula I containing sulfonic acid groups, the cyclization product is salted out from the reaction product.

The 2-arylv-triazoles obtainable by the process according to the invention, that of the formula

Ar

N.

.R,

(H)

correspond,

in which

Ar,

R2 and η

have the meaning given above,

are for the most part known and provide valuable optical brightening agents, UV absorbers and brighteners and dyestuff intermediates represent.

So are z. B. Compounds of the formula II in which Ar represents a stilbene, coumarin, naphthalimide and dibenzothiophene dioxide radical stands, excellent optical brightening

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OWOINAL INSPECTED

medium (see EP 1 108 416, 1 155 229, 1 154 995, 1 113 918 and 1 201 579, USP 3 459 744).

Such compounds in which the for a p-tolyl radical (n = 1) or Liphenyläthanreat (n = 2) is according to known Process can be converted into stilbene brighteners (see e.g. USP 3 351 592 and PP 1 480 699).

2-Phenyl-4-methyl-v-'triazole is an effective UV absorber (Chem. Abstr. 5J7, 8100 d).

The method of the invention is based on the following Examples explained in more detail.

example 1

70.6 g of the disodium salt of 4,4'-bis- (dl -Oximinoacetophenonhydrazono) -stilbene-2,2-disulfonic acid are dissolved in 500 ml of ^t 3 $ aqueous urea solution of 85 ⁰ C in the course of 2 hours at 99 ⁰ C. brought, whereby a clear yellow solution is formed. It is then refluxed. After about 2 hours, the sodium salt of the 4,4'-bis- (4-phe-

nyl-vic.-triazolyl) stilbene-2,2 * -disulfonic acid to precipitate. After 5 hours of boiling, the cyclization is complete. Now 25 g of table salt are added; one cools to room temperature, Sucks off the cyclization product and washes the paste on the suction filter with 500 ml of 3 # saline solution. For cleaning, the raw paste is dissolved in 1800 ml of boiling water and 100 ml of 40% sodium hydroxide solution is added,

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the sodium salt of 4,4 * -BIb- (4-phenyl-vtc.-triaeolyl) -stilbene-2,2 * -dieulfonic acid is obtained in the form of light yellow crystals. They are filtered off with suction and washed with 500 ml of 3 ^ strength Kochsalelusung and then 500 ml with water at 2-4 ⁰ O.

After drying, 56 g of the sodium salt are obtained Forest1

which dissolves clearly in water with a light blue daytime fluorescent fluorine.

Example 2

If the cyclization described in Example 1 is carried out in 500 nil of a 10% urea solution, the reaction is already over after boiling for 3 hours.

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Example 3

80 g of 4,4'-hydraeinostilbene-2.2 ^l -disulfonic acid, 60 g of oximinoacetophenone and 30 g of urea are mixed and 200 ml of methanol are poured over them. The suspension is brought with stirring to a temperature of 4O ⁰ C and then added with 78 g of anhydrous sodium acetate. The reaction mixture is then brought to a temperature of 50-55 ° C. and this temperature is maintained for 4 hours. The suspension of the sodium salt of 4,4 ^f -Bis- (t ^ -oximinoacetophenonhydrazonoJ-stilbene ^^ 'disulfonic acid formed after temporary dissolution is diluted with 500 ml of water and the mixture is brought to a pH of 7-8 by adding 45 ml of 50% strength potassium hydroxide solution. The methanol is then distilled off with stirring, a clear ^{solution being formed on heating at 80 ° C.} . the starting at an internal temperature of 84 ⁰ C distillation yields 260 g of an aqueous-methanolic distillate is then holding for 3 hours at 10O ⁰ Q, cooled to room temperature. sucks the cyclization product of formula

SO ₅ Well

off and it is washed on the filter with 500 ml 3 # sodium chloride solution and then with 500 ml of water 2-4 ⁰ C. It who the 305 g of a light yellow paste obtained as in Example 1, to thereby yield 112 g of a light lemon yellow crystallizate with the properties described there

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supplies.

Example 4

IO

70.6 g of the disodium salt of 4,4 '
tophenonhydrazono) -atilben-2,2 ^l -disuli "onaäure are dissolved in 500 ml of diethylene glycol at 100 ⁰ C. It is to urea and the solution kept for 4 hours at 10O ⁰ C. When pouring into 500 ml 15 #ige saline drops the Cyclization product of the formula

off, sucked off and 5

Washed saline

will. After drying, 92 g of crude product with a content of 74 i "daa a yield of 97 corresponds to S *.

Example 5

20 g N-ZJ-Phenylcumarinyl- (717 ~ CL-oximinopropiophenonhydrazon a melting point of 292 ⁰ C and 19 g of urea are boiled for 30 Hours Reset flowing in 500 ml of glycol monomethyl ether. Now are distilled off 300 ml of glycol monomethyl ether from the clear solution and cooled the residue. It crystallize 12.2 g (64.5 % of theory) of the cyclization product of the formula

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Example 6

41, 2 g of N- (3-phenyl-coumarinyl-7) -ct-oxime-noproplophenonhydrazone (95.8 #ige goods) are suspended in 200 ml of Glykolnionomethyläther. 12 g of urea and 6.9 g of potassium carbonate, dissolved in 5 ml of water, are added and the mixture is refluxed for 5 hours. On cooling, the 3-phenyl-7 / 2- (2-phenyl-5-methyl-) 1,2,5-tria2oly \ 7coumarin separates in pale yellow colored crystals, which sucked off and on the suction filter 5 times with each 20 ml of cold methanol are washed.

Example 7

35 * 5 g sodium salt of ^ -Oximinopropiophenon-IJ-sulfophenyl) hydrazone, whose preparation is described in the German patent 1670914, are dissolved in 100 ml of water and 100 ml of methanol at 60 ⁰ C. 20 g of urea are then added and the methanol is distilled off at atmospheric pressure. The reaction solution is kept at 100 ^° C. for a further 3 hours, the cyclization product already precipitating. The precipitation is completed by adding 25 g of sodium chloride, the cyclization product of the formula ■

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/ A,

scyja

suctioned off and washed with dilute saline solution.

Example 8

14.2 g of N- / p-nitrophenyl / - <λ. -oximinoacetophenonhydrazon are dissolved in 200 ml diglycol 1J50 at ⁰ C. 12 g of urea are now added and the temperature of 130 ^° C. is maintained for 8 hours. The diglycol is distilled off from the solution at 1 torr and the distillation residue is washed with water and dried. After crystallization from 150 ml of toluene, the cyclization product of the formula is obtained

NO,

in the form of light yellow crystals.

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Claims (5)

Claims t . Process for the preparation of 2-aryl-v-triazoles, characterized in that (^ C-oximinoarylhydrazones of the general formula Ar N = CR ₁ NH- HO-N = C-R, in which Ar is an aromatic carbocyclic or aromatic heterocyclic The rest is R is an aliphatic or aromatic radical, R _{0 is} hydrogen, an aliphatic or aromatic radical and the numbers 1 or 2 mean with at least 1 equivalent of urea in water, with water converts miscible polar solvents or mixtures thereof. 2. The method according to claim 1, characterized in that one ο ο the reaction is carried out at temperatures between 90 ° C. and 150 ° C. 3. The method according to claim 1, characterized in that the solvent used is water. 4. The method according to claim 1, characterized in that the solvent used is water-miscible alcohols with a boiling point - 90 ⁰ C alone or in a mixture with water. 5. The method according to claim 1, characterized in that one works with the addition of basic substances. Le A14 556 -13- 4098 1 1/1190