HU203079B - Process for producing asymmetrically substituted oil-soluble dithiocarbamates - Google Patents

Abstract

In asymmetrically substd. oil soluble metal-dithio-carbamates of formula (I) and alkylene-substd.-di:thio-c arbamates of formula (II) the substituents are: R1: 1-4C alkyl; R2: 3-12C alkyl gps. cannot be identical. Me: Cd, Ni, Pb, Zn, Sb, Mo or Cu atoms and p: 1, 2, 3 or 4 integers. (I) and (II) are prepd. from a mixt. of secondary amines (R1)2NH and (R2)2NH in (1:9)-(9:1) molar proportions and form carbon-di:sulphide in the presence of sodium or ammonium-hydroxide at a temp. - of 20 deg.C max., via di:alkyl-dithio-carbamate salts of general formula (III) and (IV). Further (III) and (IV) react at an increased temp. with MeX2 metal salts or di:halogen-alkanes of general formula X(CH2)p-X. (I) and (II) are isolated from the reaction mixt. In formulae (III) and (IV), R1 and R2, Me and p are unchanged; A: sodium or ammonium ion; X: chlorine, bromine or iodine atoms.

Description

The present invention relates to a process for the preparation of asymmetrically substituted oil-soluble dithiocarbamates. The compounds of the present invention are novel and can be used successfully as lubricating oil additives.

Numerous metal bis-dithiocarbamates and alkylene bis-dithiocarbamates have been described in the prior art. These compounds are prepared according to the process outlined in Scheme A, wherein R 'and R' are C 1 -C 12 alkyl, X is halogen, and T is a divalent metal or alkylene group [Gazz. Chim, Ital. 69, 752 (1939) and 70, 541 (1940); Thom, G.D., Ludwig, R.A., "The Dithiocarbamates and Related Compounds," Elsevier Publ. Co., Amsterdam New York (1962)].

A common structural feature of the known bis-dithiocarbamates is that they are symmetrically substituted, i.e., the two valencies of the metal atom or the alkylene group are linked together by the same groups.

Certain representatives of metal bis-dithiocarbamates, which have been produced primarily for plant protection and rubber purposes, may also be used as lubricating oil additives. It is a prerequisite for their use in the oil industry that the compounds are soluble in lubricating oils and machine greases. The oil solubility of metal dithiocarbamates is significantly influenced by the number of carbon atoms of the secondary amine; in practice, dithiocarbamates of metal having R 'and R "alkyl groups having at least 5 carbon atoms are well soluble in oil. "(Technical Publisher, Budapest, 1976/41). The same applies to the recently used alkylene bis-dithiocarbamates.

One of the best known and most commonly used representatives of dithiocarbamate metals is zinc diamyl dithiocarbamate, which has a very broad spectrum of activity and can be used as antioxidants, metal deactivators, corrosion inhibitors and anti-wear additives in gear oils, gas oils, compressor oils, , in Metalworking Oils and Machine Fats (Polishuk, A., Farmer, Η: H. NLGI Spokesman 6, 45,200-205, 1979). Molybdenum and cadmium dibutyldithiocarbamate are also broad-spectrum antioxidant, anti-wear and corrosion inhibitors; these compounds can also be used at high temperatures (U.S. Patent No. 3,509,051). Lead diamyldithiocarbamate is an EP (extreme pressura) multifunctional additive, anti-bump, anti-corrosion and antioxidant; this compound is used primarily as additives in industrial and transport gear oils, metalworking oils, machine greases and Otto engine oils. Alkylene dithiocarbamates can be used in a similar manner to metal dithiocarbamates; their environmental and application technology advantage is that ash-free additives, ie their combustion does not produce solid combustion products.

However, the widespread use of metal and alkylene dithiocarbamates is hampered by the need for relatively difficult to obtain and very expensive longer-chain secondary amines for the preparation of suitable oil-soluble compounds.

Surprisingly, some asymmetrically substituted metal and alkylene dithiocarbamates have different dithiocarbamate groups attached to the two valencies of the metal atom or the alkylene chain, and one of the two dithiocarbamate groups linked to each other has the lowest number of carbon atoms. they have a secondary amino group, are at least as good and sometimes more soluble in oils as analogous compounds having a secondary amino group with symmetrically substituted alkyl groups on both sides and their anti-oxidant, anti-corrosion, anti-wear, etc. analogous structures but with symmetrically substituted metal and alkylene bis-dithiocarbamates having longer chain alkyl groups on both sides. Given that low-carbon secondary amines, which are one of the starting materials for the preparation of asymmetrically substituted metal and alkylene bis-dithiocarbamates, are significantly more readily available and cheaper than long-chain secondary amines, our discovery provides high quality and widely used oil the preparation.

The present invention relates to a process for the preparation of asymmetrically substituted dithiocarbamates of the formula I or asymmetrically substituted alkylenediothiocarbamates of the formula (I) wherein R ^{1 is C} 1-4 alkyl and R ^{2 is C} 3-10 alkyl. with the proviso that R ¹ and R ² can never be the same, Me is Cd, Pb, Zn or Sb, and p is 1, 2, 3 or 4. The compounds of formula (I) and (Π) was prepared by reacting (R ¹⁾ 2 NH and (R ²⁾ 2 NH secondary amines of the general formula - wherein R ¹ and R ² are as defined above - (0.1-1): 1 - preferably (0.3-0, 6); 1-molar mixture is reacted with carbon disulphide at a temperature not exceeding 20 ° C in the presence of an alkali metal hydroxide, and the resulting dialkyl dithiocarbamate salts of the formulas III and IV, wherein R ¹ and R ² are above and A is an alkali metal ion - with heating metal salts of MeX ₂ or dihaloalkanes X- (CH ₂ ) p X - wherein Me and p are a. and X is halogen, isolating the compounds of formula (I) or (II) from the reaction mixture in a known manner.

The process of the invention is illustrated by the following reaction scheme (B).

In the preparation of asymmetrically substituted metal dithiocarbamates of the formula (I), the mixture of the compounds of the formulas (III) and (IV) is suitably reacted with the metal halides of the formula (MeX ₂ ) at 70100 ° C. dithiocarbamates, the analogous reaction is conveniently carried out at 30-60 ° C. The product is isolated by washing the organic phase of the reaction mixture and distilling off the volatile material. The products are usually low melting point, sometimes liquid at room temperature; each of which is soluble in oils of at least 5% by weight, which is usually a good amount of oil in the oil, which is usually a good amount of oil to obtain a good effect.

It is extremely surprising to find that the compounds of formula (I) and (II) have a higher oil solubility than analogous but two long-chain alkyl groups.

In the case of symmetric dithiocarbamates containing substituted secondary amino groups, a significant reduction in oil solubility could be expected due to the presence of lower alkyl substituted secondary amino groups. 5

For the preparation of the compounds of formula (I) and (Π), the secondary amine of formula (R ') ₂ NH is preferably dimethylamine, dictylamine, di-n-propylamine or di-n-butylamine, particularly preferably di -n-butylamine or di-n-propylamine may be used. The secondary amine of the formula (R ² ) ₂ NH 10 is preferably dipropylamine, dibutylamine, diamylamine or dihexylamine, particularly preferably dibutylamine or diamylamine.

The invention is illustrated in detail by the following non-limiting Examples

Example 1

Preparation of Asymmetrically Substituted Metal Dithiocarbamates containing 20 moles of a mixture of di- (C1-C4 alkyl) amine di-C3-C12 alkylamine and 10 moles of sodium hydroxide of the quality and molar ratios given in Table I Aqueous solution is weighed into an autoclave lined with acid-resistant enamel with a stirrer and a condenser. The mixture is cooled to 5 'C and 10 moles of carbon disulphide are added at such a rate that the temperature of the reaction mixture does not rise above 20' C. The addition of the carbon disulphide takes 3035 minutes. To the resulting mixture was slowly added 10 moles of aq. The resulting suspension is refluxed at 80-90 ° C for 2 hours and then cooled to 30-40 ° C. The viscous oil-like organic phase is separated from the aqueous phase and washed twice with 10 liters of water at 40 ° C. The organic phase is then deprotected at 50-70 mmHg and water and volatile at 80-90 ° C. The low melting point, asymmetrically substituted metal dithiocarbamates listed in Table I are obtained in greater than 90% yield. The melting point and application characteristics of the products are set forth in Table I. Tensile load and wear were determined according to ASTM D-2783 and oxidation stability was determined according to ASTM D-2272.

for comparison, zinc dibutyl dithiocarbamate is also prepared by the following procedure:

of a 20 wt.% aqueous solution of dibutylamine and 10 mol. The mixture is cooled to 5 'C and 10 moles of carbon disulphide are added at such a rate that the temperature of the reaction mixture does not rise above 20' C. The carbon disulfide was added at 35 min. cet takes. To the resulting mixture was added 10 moles of an aqueous solution of zinc chloride at 20-30 ° C, then the resulting suspension was refluxed at 85-95 ° C for 2 hours and then cooled to 20 ° C. The slurry was filtered and dried in the oven to give 98% zinc dibutyldithiocarbamate / Jr. Application characteristics of the product are given in Table I / L.

Table I

(R'izNH (R ² ) 2 NH molar ratio * MeX ₂ Op. 'C Olajöld- lótóság ♦ * Hegclízi load (N) *** O.'d Stubborn Stability, 'ov ♦ *** Abrasion mm 0 diethylamine diamyl amine 0.3 ZnCl ₂ 49 good 1800 180- 0.70 dibutylamine diamyl amine 03 ZnCl ₂ 65 good 1800 195 0.70 dibutylamine diamyl amine 0 (2 ZnCl ₂ 20 good 2200 190 0.75 dibutylamine dihcxil amine 03 ZnCl ₂ 20 good 220C 220 0.80 diethylamine dihexylamine 03 PbCl ₂ 31 good 3000 122 0.95 dibutylamine diamyl amine 03 PbCl ₂ 20 good 2230 139 1.05 dibutylamine dihexylamine 0.5 PbCl ₂ 20 good 3200 118 0.80 diethylamine diamyl amine 0.5 SbCl ₂ 37 good 2800 116 0.85 dibutylamine diamyl amine 0.5 SbCl ₂ 20 good 2300 132 0.90 dibutylamine dihexylamine 03 SbCl ₂ 20 good 3000 107 0.90 dibutylamine dibutylamine ZnCl ₂ 107 3% 2900 110 0.85

* (Molar number of amine of formula R '^ H: molar number of all amines ** measured in SN-150 oil; good if yields are at least 5% soluble in claj * ♦♦ 3% SN-150 in oily solution measured **** 03% by weight in SN-150 oil solution

Example 2

Preparation of asymmetrically substituted alkyl-n-bis-dithiocarbamates moles, a. and a 20 wt.% aqueous solution of a mixture of di (C 1-4 alkyl) amine di (C 3 -C 12 alkyl) amine and 10 molar sodium hydroxide in the quality and molar ratios given in Table 1, with stirring at 65 ° C. equipped with an acid-resistant enamel-lined autoclave mfií'Í'i.tc. The mixture was cooled to 5 'C and, with vigorous stirring, 10 moles of carbon disulphide were added at a rate such that the temperature of the reaction mixture did not rise above 20' C. After addition of the carbon disulfide, 6 moles of dichloromethane are added and the mixture is heated to 40-50 ° C. Reaction-35

The aqueous phase is separated off warm and the organic phase is washed twice with 10 liters of water. The organic phase was decontaminated with water and volatile at 70 mmHg at 80-90 ° C, then 100 g of clarifying earth was added and filtered.

The application characteristics of the products obtained are a

II. and its properties in Table ΠΙ. in Table. II. Comparative data for known methylene bis (dibutyldithiocarbamate) are also provided in Table II. Friction load and wear were determined according to ASTM D-2783 and oxidation stability was determined according to ASTM D-2272.

Π. spreadsheet Serial number Amino-components molar ratio * Olajold- authorities ** scarring load (N) *** Oxidation stability, minutes ♦ *** Abrasion mm 0 (R ') 2NNH R ² hNH First diethylamine dibutylamine 03 good 2400 410 1.15 Second diethylamine dibutylamine 0.4 good 2400 360 1.10 Third diethylamine dibutylamine 0.6 good 2800 350 1.10 4th diethylamine dibutylamine 0.8 good 2600 340 13 5th diethylamine di- (n-propyl) amine 0.2 good 2600 110 0.8 6th diethylamine di- (n-propyl) amine 0.4 good 2800 105 0.8 7th diethylamine di- (n-propyl) amine 0.6 good 3000 100 0.8 8th diethylamine di- (n-propyl) amine 0.8 good 2900 120 0.85 9th dibutylamine dibutylamine - good 1800 - 1.0 * Mole of amine of formula (R ¹ ) ₂ NH: Mole of all amines ** SN-150 measured in oil; the value is good if the product is soluble in oil of at least 3% *** Measured in 3% w / w SN-150 oil solution **** Measured in 0.5 wt% SN-150 oil solution

ΙΠ. spreadsheet Row- song Density at 20 ° C [g / cm ³ ] N S IR spectrum γπυχ [cm ^-1 ] theoretical (%) found (%) theoretical (%) found (%) First 0.97 6.6 6.58 30.22 30.1 2920,1460,1420,1385,1280,730 Second 0.98 6.97 6.85 31.91 31.9 2430,1460,1425,1390,1280,735 Third 1.01 7.38 739 33.80 33.7 2970,1460,1420,1390,1280,730 4th 1.05 7.85 7.80 35.93 35.7 2930,1460,1430,1360,1280,730 5th 0.98 7.38 7.35 33.8 33.6 2940,1460,1425,1360,1280,735 6th 0.99 7.61 7.58 34.83 34.6 2935,1455,1430,1360,1280,730 7th 1.01 7.85 7.83 35.9 36.0 2940,1455,1430,1360,1280,730 8th 1.03 8.1 8.05 37.2 37.3 2945,1455,1430,1360,1280,735

PATENT CLAIMS

Claims (4)

PATENT CLAIMS A process for the preparation of asymmetrically substituted metal dithiocarbamates of the formula (I) or of the asymmetrically substituted alkylene dithiocarbamates of the formula (I) in which R ^{1 is C 1} -C ¹ alkyl and R ^{2 is C} 3 -C 10 alkyl, that R ¹ and R ^{2 can} never be the same, Me is Pb, Zn, Sb or Cd, p is 1, 2, 3 or 4, characterized in that (R ') ₂ NH and (R 1 -NH) of a secondary amine (0.1-1): 1 molar mixture of the compounds R * and R ^{2 as} hereinbefore defined in the presence of an alkali metal hydroxide at a temperature below 20 ° C 65, followed by the reaction of (III) and The dialkyl dithiocarbamate salts of formula (IV), wherein R ¹ and R ² are as defined herein, A is an alkali metal ion, are heated with MeX ₂ metal salts of formula 55 or X-CH 2 -X by reacting a compound of formula (I) or (Π) with the dihaloalkanes of formula (II) wherein Me and p are as defined above, X is halogen, and then from the reaction mixture. A process according to claim 1, wherein the mixture of secondary amines of formula (R ') ₂ NH and (R ² ) ₂ NH (0.3-0.6): 1 molar. 3. The process according to claim 1 or 2, wherein the amine of formula (R ') ₂ NH is For example, ethylamine, di- (n-propyl) amine or di- (n-butyl) amine are used. 4. Process according to any one of claims 1 to 3, characterized in that the amine of formula R 1 -NH is dipropylamine, dibutylamine, diamylamine or dihexylamine.