DE2726114A1 - IRON (II), IRON (III), COPPER (II), ZINC, MANGAN (II), COBALT (II) AND NICKEL (II) CHELATES FROM N, N'-TO (2- HYDROXYBENZYL) - UREA DERIVATIVES, HERBAL ARTISTIC DUCTS AND N, N'-BIS- (2-HYDROXYBENZYL) UREA DERIVATIVES AND METHODS FOR THE PREPARATION OF THE LATER AND THE FIRST - Google Patents

Description

Stephan G. beszedes patent attorney

8060 DACHAU NEAR MUNICH

BOX 11S8

AM HEIDEWEG 2

27261U

TELEPHONE: DACHAU 4371

Post account Munich (bank code 700 100 (O)

Account no. 1368 71

Bank account no. Θ06 370 at the Krall- and 8t »* - Sparkassa Dachau-Indaradorf (BLZ 700 515 40)

(VIA Bavarian « Landeabank

Girozentrale, MOnchan)

P 998

description

for patent application

PKTI NITROGOmUVEK

Varpalota, Hungary

concerning

Isen (II) -, iron (III) -, copper (II) -, zinc , Manp; an (II) -, cobalt (II) - and nickel (II) chelates of N, N '-bis- (2-H.ydrox.ybenzyl) -urea derivatives , such containing artificial fertilizers and N, N'- bis- (2-hydroxybenzyl) -urea derivatives and processes for the production of the latter and the

the former

The invention relates to new heavy metal chelate complexes of N, N'-bis- (2-hydroxybenzyl) -urea derivatives, artificial plant fertilizers containing such and N, N'-bis- (2-hydroxybenzyl) - urea derivatives which form stable chelate complexes with heavy metals, and a process for the preparation the former and the latter.

70 "H" 1/0710

Aue HeIv. Chim. Acta, 14 (1951), 555 to 558, Chemical Abstracts, 21 »3 855k and German Patent 511 520, the compound N, IT'-bis- (2-hydroxy-5-methylbenzyl) - urea is known. Furthermore, int from the German patent specification 511 5? Q 11.11 ^l -bis- (4-Hj ^r dro: g ^r -5-carboxybjnzyl) -urea known- But according to this publication, these compounds are used alο intermediates in the Toerfarbenindu3trie. In contrast, it is not known that they are chelating agents or that they can even be used for plant fertilization.

It is already general bol: annt that in the practice of large-scale agricultural plant cultivation the nutrient replacement of the soil to a decisive extent by technically or industrially produced Artificial fertilizers can be made · In artificial fertilization, nitrogen, potassium and phosphorus play a role the most important hell. However, through many experiments and also through practice it has been proven that even through in constantly Increasingly made use of nitrogen, phosphorus and potassium containing artificial fertilizers the biological Maximum yield of the plants cannot be achieved. The reason for this is also already well known Fact dai? the plants for their healthy development in addition to the aforementioned Ilauptnöhro elements as nutrients and so-called Need to learn a trace of micro-learning. In addition to the in The main nutritional element given in large Morse code is ability of the soil to give off Spuron or micro-elements is generally not sufficient. So most of the time it is It is necessary to add the necessary trace or micro-elements to the soil so that the IlauptnUhretoffe can actually bring about the coveted increase in yield.

This finding is already in use at present

709331/0716

^a "272611A

a number of types of artificial fertilizers, which, in addition to the main nutrients, also contain trace elements or micronutrients included, in trade. These trace or micro-elements are either in the form of inorganic salts or bound to various organic substances (chelating agents). Through well-known botanical experiments it has already been proven that the plants contain trace or micro-elements bound to organic substances (be it via the roots, be it via the leaves) can be absorbed and used more easily than in the form of inorganic ones Trace or micro-elements applied to salts.

For the production of compounds from traces or traces bound to organic substances, i.e. chelating agents Microelements and preparations containing them and their use are numerous examples in the specialist literature to find.

For example, from the Hungarian patent specification 154 287 heavy metal chelates, which are used as chelating agents in the 5-positions of their benzyl groups substituted Ν, Ν'-bis- - (2-Hydroxybenzyl) ethylenediamine derivatives are known. These are suitable for the treatment of the deficiency disease of plants known under the name iron ο hlorose. The decisive one The disadvantage of the process described in this patent is that in the preparation of the chelating agent in it remains such an amount of inorganic impurities that that from this chelating agent produced metal chelate for plant treatment can only be used in low concentration, which is its effect significantly restricts. The removal of the inorganic impurities has not yet been solved.

70CÜa 1/0716

^ o 27261H

In U.S. Patent 3,742,002 and in Hungarian Patent 162 64-9 are heavy metal chelates which are available as Chelating agents substituted in the 5 positions of their benzyl groups Have N, N'-bis (2-hydroxybenzyl) amino acid derivatives, described. These compounds are also used to treat deficiency diseases in plants. you The disadvantage is that the production of the chelating amino acid derivatives is due to the fact that they are not exactly easy to access the amino acids used as starting materials is extremely expensive. It also points to these connections the chelating molecule has no nitrogen fertilizer effect.

The invention is based on the problem of remedying of the disadvantages of the prior art, new heavy metal chelates of organic nitrogen compounds with superior Effect against deficiency diseases in plants with simultaneous nitrogen fertilizer effect, which in one used in a wide range of concentrations and manufactured from raw materials that are more easily and more easily accessible can, artificial plant fertilizers with a content of these and as intermediate products for the production of the new heavy metal chelates useful chelating agents and a process for the preparation of the latter and the new heavy metal chelates create.

For the production of chelate complexes stable with heavy metals Chelating agents resulting from starting materials that are much more readily and easily accessible have become numerous Attempts made.

It has now been found, surprisingly, that the new N, N'-bis (2-hydroxybenzyl) - -urea derivatives fully meet the above requirements.

709 8H1 / 0716

.j 27261H

The invention therefore relates to iron (II), iron (II), copper (II), zinc, manganese (II), cobalt (II) and nickel (II) chelates (summarized in many ways below referred to as heavy metal chelates) of N, N'-bis (2-hydroxybenzyl) - urea derivatives of the general formula

0 H

C-N-G-N-C

wherein

lind

independently of one another for radicals of the general formula (s)

- SO, M

and or

- COOM

in the latter

70988 1/07 16

M hydrogen, an alkali metal atom,

"^" 272611A

fo

an alkaline earth metal atom, an ammonium group, a monoethylamino group, a diethylamino group or a tri-ethylamino group means,

stand
or

one of X _x . and X ₂ denotes a straight-chain or branched alkyl radical having 1 to 4 carbon atoms and

the other of X _x . and X _{2 is} a remainder of the general

formula

or

- COOM

in the soft latter

M is hydrogen, an alkali metal atom, an alkaline earth metal atom , 709881/0716

272611 A

an ammonium group, a monoethylamino group, a diethylamino group or a triethylamino group means,

represents

as well as mixtures thereof.

The invention also relates to N, N'-bis (2- hydroxybenzyl) urea derivatives of the general formula

0 H

C-N-C H

where X ^ and X- as above foatolosed uirul. Doron properties This is because and constitution are the cause of the superior properties of the heavy metal chelates according to the invention.

The alkyl radical for which X- or X- is preferably
can stand, a methyl or ethyl radical.

7 0 'J ti 01/0 7 1 8

■ $ "27261Η

One of the great advantages of the heavy metal chelates of the invention consists in the fact that, surprisingly, they also have a nitrogen fertilizer effect per se by the underlying Ν, Ν'-bis- - (2-Hydroxybenzyl) urea derivatives of the formula I also have this effect in addition to the chelating properties. By Resorption experiments with radioactive isotopes have been found that the metal content of the invention Heavy metal chelates of N, N'-bis (2-hydroxybenzyl) urea derivatives of formula I absorbed relatively quickly by the plant both through the foliage and through the roots will. As a result, the metal content of the heavy metal chelates is used to the maximum. Since in the Ν, Ν'-bis- - (2-Hydroxybenzyl) urea derivatives of the formula I are the benzene rings also have carboxyl and / or sulfonyloxy groups as substituents and salts can be formed with them, where magnesium can also be used for salt formation, this gives the plant the opportunity at the same time supply the magnesium, which is indispensable for the formation of chlorophyll.

Furthermore, according to the invention, artificial plant fertilizers which contain 1 or more heavy metal chelates according to the invention, optionally together with 1 or more known artificial fertilizers and / or 1 or more conventional extension and / or Auxiliary materials, included, provided.

Preferably, the plant fertilizer of the invention contain Schwermetallchelate according to the invention in amounts of from 0.1 to 95 wt .-%, the optionally present known fertilizer or the optionally present known fertilizer in amounts of 3 to 95 wt .-% and the optionally present drawing and / or auxiliaries or any existing ones

70S881 / 0716

272611 A

Extenders and / or auxiliaries in an amount required to supplement 100% by weight.

The invention also relates to a process for the preparation of the N, N'-bis (2-hydroxybenzyl) urea derivatives of the formula I according to the invention and the heavy metal chelates according to the invention or mixtures of the latter derived from them, which is characterized in that \ | Urea with formaldehyde and a phenol derivative or phenol derivatives of the general formula (s)

II

and (if X ,, is different _{from X 2} ) / / or (if X ₁ is X ₃ )

III

70ÖS81 / 0716

- 10 -

27261IA

wherein X ^, and X ₂ ^w ^ - ^e are defined above, is reacted, where per mole of urea 2 to 2.5 moles of formaldehyde and, in the case that X ^ is X ₂ , 2 to 2.5 moles of the phenol derivatives Formula II or III and, in the event that X, - _{is different from X 2} , 1 to 1.3 mol of the phenol derivative of the formula II and 1 to 1.3 mol of the phenol derivative of the formula III are used, and optionally the N obtained, N'-bis (2-hydroxybenzyl) urea derivative of the formula I per mole of the same with 0.5 to 1 mole of 1 or more water-soluble iron (II), iron (IIl), copper (II), zinc , Manganese (II) -, cobalt (II) - and / or nickel (II) salts is implemented.

The reaction of the urea with the formaldehyde and the phenol derivative or the phenol derivatives of the formula (s) II and / or III and / or the reaction of the N, N ^l -bis- (2-hydroxybenzyl) urea derivatives or the N, N ^1- bis (2-hydroxybenzyl) urea derivatives of the formula I with the water-soluble iron (II), iron (III), copper (II), zinc, manganese (II), cobalt (II) - And / or nickel (II) salt (s) in an aqueous medium, optionally in the presence of methanol, carried out.

^{It is expedient to use 30 to 60 °} C. as the reaction temperature for the reaction of the urea with the formaldehyde and the phenol derivative or the phenol derivatives of the formula (s) II and / or III. In the event that p-phenolsulphonic acid salts or p-hydroxybenzoic acid salts are to be implemented as phenol derivatives, these can be used in the form of the p-phenolsulphonic acid or p-hydroxybenzoic acid and base on which they are based with separate addition of the same, the p-phenolsulphonic acid salts or p Forming hydroxybenzoic acid salts in situ.

709 «» 1/0716

- 11 -

The N, N ^l -bis (2-hydroxybenzyl) urea derivatives of the formula I obtained can be isolated and purified with the aid of customary procedures, such as evaporation or recrystallization.

As already mentioned, complex formation can take place with one heavy metal salt, but also with several heavy metal salts can be done at the same time. For example, heavy metal chelate complexes according to the invention which are used as metals Contain iron (III), copper (II) and manganese (II) ions, getting produced.

The phenol derivatives of the formulas II and III used as starting materials are commercially available chemicals, respectively may have been prepared by methods known in organic chemistry.

The heavy metal chelates according to the invention can be used for calibration alone, for example in the form of 0.5 to 50% by weight aqueous solutions, can be used for artificial fertilization. Mostly, however, they are used together with known artificial fertilizers, for example with urea, superphosphate, potassium salts and / or ammonium nitrate. The the invention Heavy metal chelates and the known preparations containing artificial fertilizers can be liquid or solid and how already mentioned, in addition to the active ingredients, also contain the customary extenders and / or auxiliaries. As an aid For example, substances that prevent adhesion and dispersants can be used.

The invention is explained in more detail by means of the following examples.

709881/0718

- 12 -

example 1

N, N'-bis- (2-hydroxy-5-potassium oxysulfonylbenzyl) - -urea

A 1,000 cubic meter flask equipped with a reflux condenser and a stirrer was charged with 426.42 grams of technical grade p-phenolsulfonic acid potassium and 400 cubic meters of water. After the substance had dissolved, the pH of the solution was checked and, if necessary, adjusted to 6 to 7 with a 50% potassium hydroxide solution. Then 60 g of urea were added to the solution and, after this had dissolved, 167-25 g of a 37% strength aqueous formaldehyde solution were added. The reaction mixture was held for 50 minutes at 30 to 60 ⁰ C, after which its pH was adjusted with a 50% potassium hydroxide solution to 7.2 to 7.5 and the mixture was heated under reflux for 7 hours to boiling * was then the reaction mixture evaporated to dryness. Thus, N, N'-obtained bis- (2-hydroxy-5-kaliumoxysulfonylbenzyl) -urea having a melting point of 270 ⁰ C (with decomposition) in a yield of 90% of theory.

Nitrogen content:

calculated: 5 »51%;
found: 5 »

Example 2

N, N'-bis- (2-hydroxy-5-magnesium-sulfonylbenzyl) -urea

370.30 g of p-phenolsulfonic acid magnesium and 400 cm * of water were introduced into a 1,000 car flask equipped with a reflux condenser and a stirrer. That

709881/0716

- 13 -

-yf-

19 27261H

The mixture obtained was ^{heated to 35 to 60 °} C. in order to bring the p-phenolsulfonic acid magnesium into solution. After this had taken place, 60 g of urea were added to the solution and, after this had dissolved, a 50% strength potassium hydroxide solution was added, if necessary, to adjust the pH to 6 to 7. Then the reaction mixture with 165 * 2 was added cnr of a 37% aqueous formaldehyde solution and then held for 30 minutes at 35 to 60 ⁰ C and finally its pH with a 50% potassium hydroxide solution to 7 * 2 to 7 » 5 set. The mixture was refluxed for 7 hours and then evaporated to dryness. Thus, N, N'-obtained bis- (2-hydroxy-5-magnesiumoxysulfonylbenzyl) -urea having a melting point of 25 ^ ⁰ C (with decomposition) in a yield of 96% of theory.

Nitrogen content:

calculated: 6.16%;
found: 6.07%

Example 3

N, N -Bie- (2-Hydroxy-5-potassium oxysulfonylbenzyl) -

-urea

60 g of urea and 200 cm ^ of water were placed in a 1,000 cm 'flask equipped with a reflux condenser, a thermometer, a metering funnel and a stirrer, and then 164.5 g of a 37% strength iOnaldehyde solution were added. The pH of the mixture was adjusted to 7 to 8 with a 50% strength potassium hydroxide solution and then the addition of technical grade p-phenolsulfonic acid was started. Dosing was carried out so that the temperature of the mixture did not rise above 60 ⁰ C. After all of the p-phenolsulfonic acid had been added, the reaction mixture was with

709881/0716

27261IA

112.2 g of solid potassium hydroxide were added, with constant stirring. Finally the reaction mixture was evaporated. Thus N, N'-bis (2-hydroxy-5-potassiumoxysulfonylbenzyl) urea with a melting point of 271 ° G (with decomposition) was obtained in a yield of 96.4% of theory ,

Nitrogen content:

calculated: 5.51%;
found: 5.44%.

Example 4

Iron (III) chelate complex of N, N'-bis- (2-hydroxy- -5-potassium (oxysulfonylbenzyl) urea

1 mol of the chelating agent N, N ^t -bis (2-hydroxy-5-potassium oxysulfonylbenzyl) urea prepared as described in Example 1 was dissolved in 500 cnr water. The resulting solution was heated to 40 to 70 ° C., whereupon 244.5 g (0.9 mol) of iron (II]) chloride hexahydrate in solution in 300 cnr of water were added. The reaction mixture was held for 30 minutes at 40 to 60 ⁰ G and the resulting solution was evaporated to dryness. The iron (III) chelate complex of N, N'-bis (2-hydroxy-5-potassiumoxysulfonylbenzyl) - • urea with a melting point of 203 ° C. (with decomposition) was obtained in a yield of 95% of theory.

Nitrogen content:

calculated: 4.99%;
found: 4.83%

7098R1 / 07 1 fi

- 15 -

27261H

Example 5

Iron (III) / copper (II) / manganese (II) mixed chelate complex of N, N'-bis (2-hydroxy-5-magnesiumoxysulfonylbenzyl) urea

Ea, 1 mol of the chelating agent N, N ^l -bis (2-hydroxy-5-magneaiumoxysulfonylbenzyl) urea prepared as described in Example 2 was dissolved in 500 cnr water. The resulting solution was heated to 40 to 70.degree. Then, 0.3 mole of iron (IIl) chloride hexahydrate were, 0.3 mol of copper (II) - sulfate pentahydrate, and 0.3 mole of manganese (II) -sulfattetrahydrat in the form of a prepared with a total of 500 cnr heated to 70 ⁰ C water solution added. The reaction mixture was kept at 60 to 80 ^° C. for 30 minutes and then evaporated to dryness. The iron (III) / copper (II) / manganese (II) mixed chelate complex of N, N'-bis- (2- -hydroxy-5-magnesiumoxysulfonylbenzyl) urea with a melting point of 231 ° C (with decomposition) obtained in a yield of 97% of theory.

Nitrogen content:

calculated: 5.07%;
found: 4.92%.

Example 6

Iron (II) chelate complex of N, N'-bis (2- hydroxy-5-carboxybenzyl) urea

The procedure described in Example 1 was followed , but with the difference that instead of the

7Ü98R1 / 071B - 16 -

272611A

p-phenolsulfonic acid potassium 232 g of p-hydroxybenzoic acid were used and 300 cm of methanol were added to the reaction mixture. The resulting chelating agent N, N'-bis (2-hydroxy-5-carboxybenzyl) urea was mixed at 40 to 70 ° C. with an aqueous solution of 1 mol of iron (II) sulfate heptahydrate. The mixture was kept at 60 to 80 ° C. for 30 minutes and then evaporated to dryness. The iron (II) chelate complex of N, N'-bis (2-hydroxy-5-carboxybenzyl) urea with a melting point of 223 ⁰ G (with decomposition) was obtained in a yield of 96% of theory.

Nitrogen content:

calculated: 7io5%;
found: 6.88%.

Example 7

Zinc chelate complex of N, N'-bis- (2-hydroxy-5- -potassium oxycarbonylbenzyl) urea

The procedure described in Example 1 was repeated, with the difference that 308 g of p-hydroxybenzoic acid potassium were used in place of the p-phenolsulfonic acid potassium and 300 cnr methanol were added to the reaction mixture. The resulting chelating agent Ν, Ν'-bis- (2-hydroxy-5-potassium oxycarbonylbenzyl) urea was mixed at 40 to 70 ° C. with an aqueous solution of 1 mol of zinc sulfate heptahydrate. The mixture was kept at 60 to 80 ^° C. for ~ hours and then evaporated. The zinc chelate complex of N, N'-bis (2-hydroxy-5-potassium oxycarbonylbenzyl) urea with a melting point of 229 ° C. (with decomposition) was obtained in a yield of 94% of theory.

709881/0716

27261H

Nitrogen content:

calculated: 4.97%; found: 4.81%.

Example 8

Copper (II) chelate complex of N- (2-hydroxy-5- -methyrbenzyl) -N '- (2-hydroxy-5-carboxybenzyl) -

-urea

The procedure described in Example 1 was followed, but with the difference that 154 g of p-hydroxybenzoic acid and 107 g of p-cresol were used in place of the p-phenolsulphonic acid potassium, and 300 cnr of methanol were added to the reaction mixture. The resulting chelating agent N- (2-hydroxy-5-methylbenzyl) -N '- (2-hydroxy-5-carboxybenzyl) urea was mixed with 1 mol of copper (II) sulfate pentahydrate dissolved in water. The mixture was kept at 60 to 80 ° C. for -κ hours and then evaporated. So the copper (II) chelate complex of N- (2- -hydroxy-5-methylbenzyl) -N '- (2-hydroxy-5-carboxybenzyl) - -urea with a melting point of 169 ° C (with decomposition) in obtained a yield of 90% of theory.

Nitrogen content:

repaid: 7.11%; found: 7.02%.

709881/0716

- 18 -

27261H

Example 9
Artificial fertilizer mixture

94 parts by weight of urea

5 parts by weight of chelate complex according to Example 4 or 1 part by weight of sulphite waste liquor powder

The components were ground to a homogeneous powder . An aqueous solution Aue this could be prepared.

Example 10
Complex artificial fertilizer mixture

30 parts by weight of superphosphate

30 parts by weight of technical grade potassium chloride (potash salt) 38 parts by weight of ammonium nitrate
2 parts by weight of the chelate complex according to Example 5

The ingredients were ground to a homogeneous mixture. It could be sold as a powder or as a suspension .

Example 11
Complex artificial fertilizer mixture

30 parts by weight of monoammonium phosphate 40 parts by weight of technical grade potassium chloride 25 parts by weight of urea
5 parts by weight of chalate complex according to Example 5

709RS 1/0716

27261U

The components were ground to a homogeneous mixture and this could be sold as a powder or as a liquid preparation .

Example 12
Complex artificial fertilizer mixture

30 parts by weight of superphosphate

30 parts by weight of technical grade potassium chloride 30 parts by weight of urea

10 parts by weight of the chelate complex according to Example 5

The ingredients were ground to a homogeneous mixture. It could get del as a powder or as a suspension in the Han.

Example 13
Zinc-containing artificial fertilizer mixture

50 pounds 207 parts by weight urea

20 parts by weight of technical grade potassium chloride 30 parts by weight of the chelate complex according to Example 7

The components were ground together homogeneously and this could be sold as a powder or as a liquid preparation .

Claims 709881/0716

Claims (1)

27261Η Claims Iron (II), iron (III), copper (II), zinc, manganese (II), cobalt (II) and nickel (II) chelates of N ₁ N'-bis (2- Hydr ο xybenzyl) urea derivatives of the general formula C-N- Il wherein and X-, / irir I p, vtmn I π »· πΊογ for · remainders of the general formula (ii) -SO ₅ M _ and / or
- COOM, 709RR1 / 0718 in the soft latter M hydrogen, an alkali - 21 - ORiGiNAL INSPECTED 27261U metal atom »an alkaline earth metal atom, an ammonium group, a monoethylamino group, a diethylamino group or a triethylamino group means , stand
or one of X- and Xp is a straight or branched alkyl chain
means up to 4 carbon atoms and the other of X- and X2 a remainder of the general formula - SO ₃ M or - COOM in the soft latter 0 P ä η 1/0 7 1 6 ^M hydrogen, an alkali - 22 - 77261U means metal atom, an alkaline earth metal atom, an ammonium group, a monoethylamino group, a diethylamino group or a triethylamino group, represents as well as mixtures thereof. Iron (II) -, iron (III) -, copper (II) -, zinc,
Manpane (II), cobalt (II) and nickel (II) chelates of N, N ¹ -bis- (2-hydoxybenzyl) urea derivatives according to Claim 1, characterized in that the alkyl radical for X,. or ethyl radical. or Xp may be a methylN, N ¹ bis (2-hydroxybenzyl) urea derivative of
general formula C-N-C-N-C 27261U wherein X ^ and X- as defined in claim 1 or 2 are. 4.) Artificial plant fertilizer, characterized by a Content of 1 or more compounds according to claim 1 or 2, optionally together with 1 or several known artificial fertilizers and / or 1 or more conventional extenders and / or auxiliaries. 5) Artificial plant fertilizer according to claim 4, characterized in that that he the compound (s) according to claim 1 or 2 in amounts of 0.1 to 95% by weight, any known artificial fertilizer present or any existing known artificial fertilizers in amounts of 3 to 95 wt .-% and the optionally present Extender and / or adjuvant or the optionally present extender and / or Contains auxiliaries in an amount required to supplement 100% by weight. wise mixtures, according to claim
3J "Ü indicates that one is ^ arnst Process for the preparation of the compounds relating to 1 up to 3 »thereby geit ldhd £ u denotes ^/ dai ^A 1nanV ⁱ Sarnstoff with formaldehyde and - - a phenol derivative or phenol derivatives of the general formula (s) II and (if / or (if is different from X ₂ ) / is the same as X ₂ ) III wherein X _x and Xp are as defined in claim 1 or 2, reacted, 2 to 2.5 moles of formaldehyde per mole of urea and, in the case that X ₁ is Xq, 2 to 2.5 moles of the phenol derivative of the formula II or III and, if X ₁ is different from X ₂ , 1 to 1.3 mol of the phenol derivative of the formula II and 1 to 1.3 mol 709881 / 071G ^6th 27261U of the phenol derivative of the formula III used, and optionally the resulting N, N'-bis (2-hydroxybenzyl) urea derivative of the formula I with 0.5 to 1 mole of 1 or more water-soluble iron (II), iron per mole thereof (IIl) -, copper (H) -, zinc, manganese (II) -, cobalt (II) - and / or nickel (II) salts. 7.) Process according to claim 6, characterized in that the reaction of the urea with the formaldehyde and the phenol derivative or the phenol derivatives of the formula (s) II and / or III and / or the reaction of the N, N ¹ -bis- (2-Hydroxybenzyl) urea derivatives or the N, N'-bis (2-hydroxybenzyl) urea derivatives of the formula I with the water-soluble iron (II), iron (III), copper (II) zinc (s) -, Manganese (II) -, KoDaIt (^ I) - and / or nickel (II) saline (s) in an aqueous medium, optionally in the presence of methanol.