The present invention concerns new N-alkyl or N-acyl derivatives of N,N-bis(2,2-dimethyl-2-carboxylethyl) , the manufacturing procedure and utilization of the same.

^■ j The formula of the new compounds of the invention is as follows.

R'

I u wherein R and R' ' are similar or different ^or -aryl groups, R ' is a C _β -C^-al l or an aralkyl group which may contain an ester group in the middle of the carbon chain.

20 It is known in the art that the primary and secondary amines react with formaldehyde and isobutylaldehyde (cf. EP No. 46288 and Arch. Pharmaz. 308/75, p. 352), producing either direct-chain or cyclical Mannich reaction products (formulae 1 and 2).

25 (1) R-NH ₂ + 2 HCO + (CH ₃ ) ₂ CHCHO --->

R

N- —CH ₂

CH ₂ C CH ₃ ) ₂

0 ^• CH \

30 OH

(2) R ₂ NH + HCHO + (CH ₃ ) CHCHO ---> R ₂ N-CH ₂ -C-CHO

35 ^CH 3

In the present invention, the modified Mannich reaction is used as an intermediate step in the preparation of different N-alkyl- and N- acyl-derivatives of N,N-bis(2,2-dimethyl-2-carboxylethyl)amine in accordance with the following reaction formulae (3-7) .

(3) NH Y + 2 HCHO + 2 (CH ₃ ) ₂ CHO --> HN(CH ₂ - HO) ₂ HY

CH ₃ C

This condensation reaction (3) in which the group Y may be halide or sulphate can be accomplished at 50 to 90 °C in about three hours, either under refluxation conditions or under small overpressure using paraformaldehyde, trioxane or 40% of aqueous formaldehyde 5 solution for starting material.

Thereafter, the obtained compound is oxidized as taught by formula (4):

₂ HY

II 5

The oxidization reaction (4) can be performed using conventional oxidization procedures such as oxygen, ozone, peroxide, acid halide, permanganate, chromate, or dichromate oxidization. A particularly advantageous oxidization procedure is e.g. oxidization with about 0 50% hydrogen peroxide, which takes about three hours at 50 to 75°C.

The oxidized product is esterized according to the reaction (5) :

₂

III

The esterification of the compound II can be accomplished using a number of conventional esterification procedures with organic or mineral acids (p-toluene sulphonic acid, HCl, etc.) for catalyst. It is particularly advantageous to use gaseous hydrochloric acid, and the reaction is accomplished at 100 to 150°C, its duration being about three to six hours.

Thereafter, the esterified product is acylated (formula 6) or alkylated (7) .

1C

R'-CO-X CH-a

I (6) III + or -> R'-CON(CH ₂ -C-CO-OR) ₂

(R'-C0) ₂ 0 CH ₃ c IV

V

20

In the formulae 1-7, R and R' refer to a similar or different alkyl or aryl group with 1-12 carbon atoms, and R' ' refers to an alkyl or aryl group or a group which in addition to the hydrocarbon chain contains an -0-OR group. X refers to halogen.

25

The N acylation of the compound III can be performed using advan¬ tageous acid halide or anhydride. More advantageous is acylation with acid chloride at 20 to 100°C for 2 to 20 hours.

0

The N alkylation of the compound III can be performed e.g. using the ester of 2-chloride acetic acid at 140 to 150°C for 3 to 8 hours.

The compounds of type IV and V concerned in the present invention •a,- are therefore new in chemical composition, manufacturing process and applications. Their manufacture and testing in particular for uses as PVC plasticizers and stabilization are described more in detail in the following examples.

Example 1

Item A

5 In a reactor, which was provided with a mixer, a reflux condenser and a thermometer, 66.9 g ammonium chloride, 162 g formaline and 144 g isobutyraldehyde and 1 ml hydrochloric acid were charged. The mixture was heated up to 60°C, whereby the isobutyraldehyde started to be refluxed. At the end phase of the refluxation the temperature

"JC was raised to 80°C at which the boiling was continued for 2.5 hrs. The obtained condensation product (362 g) was dissolved in acetic acid and heated to 60°C, whereafter 158.1 g 47% hydrogen peroxide was added for about one hour. After the addition, the mixture was boiled for 2 hrs at 70 to 75°C. The water was evaporated from the

^• J5 reaction mixture, and the raw product thus obtained was recrystallized from the acetic acid-ethyl acetate mixture. The crystallized product is filtered and washed with ethyl methylketone-toluene mixture and petroleum ether. The melting point of the hydrochloride salt of the iminod c acid II was 175 to 179°C and the yield 145.3 g (57.3% of

20 the theoretical yield based on the quantity of the isobutanale used; 13CNMR/ppm: 21.9, 39.7, 55.8 and 178.7) .

Item B

25 The hydrochloride salt of iminodiacid II (101.5 g) , 2-ethylhexanol (220 g) and toluene (150 ml) were charged in a reactor to which a Dean & Stark water separation apparatus and equipment for feeding the hydrogen chloride gas were connected. The mixture was boiled at the boiling point of toluene for about 6 to 7 hrs, or until all water

30 produced in the reactor had been distilled into the water separation apparatus with the toluene in the form of azeotropic mixture. Hydrogen chloride gas was conducted slowly throughout the entire reaction. Ether was added into the reaction mixture and the organic phase thus obtained was washed with diluted NaOH solution and water. The dis-

35 solvents and the excess alcohol quantity were distilled off. The product, the di(2-ethylhexyl)-ester of iminodiacid, (III, R is 2- ethylhexyl) , was distilled at vacuum, the b. p. being 150 to 160°C

per 0.3 bar. The yield was 115 g (65.2% from the theoretical quantity) and the purity of the product was 98% (GC) . Identification 13CNMR/ppm: 11.1-39.9 (2 x £C), 43.9 (2 x quaternary C) , 59.5 (2 x N-CH ₂ ) , 66.6 (2 X -0-CH ² ), 177.4 (2 X C=0) .

Item C

22 g di(2-ethylhexyl)ester III of iminodiacid and 4.3 pyridine were dissolved in dry diethyl ether. In the mixture, 8.5 g n-octanoyl Q chloride dissolved in dry ether were added. The reaction mixture was refluxed at the boiling point of the ether for 3 hours. The product mixture was washed with diluted hydrochloric acid, with diluted NaOH solution and, finally, to make it neutral, with water. The raw product (27.0 g) obtained after the evaporation of the dissolvent contained 5 90% N-acylated product IV in which R was 2-ethylhexyl and R' n-heptyl. Identification: 13 CNMR/ppm: 11.1-39.1. (25C) , 43.9 & 44.3 (2 x quaternary C>, 53.4 & 55.8 (2 x N-CH ₂ -), 67.1 & 67.5 (2 x -0-CH ₂ -), 174.8 & 176.7 & 177.2 (3 x C «0) .

Example 2

The reaction performed in Item C of Example 1 with 22 g di(2-ethyl¬ hexyl)ester of iminodiacid was repeated, but instead of the n-octanoyl chloride, 8.5 g 2-ethylhexanoylchloride were used. The reaction mixture was refluxed for 5 hours at the boiling point of the ether and thereafter, it was mixed for further 20 hrs at room temperature. The reaction mixture was washed and treated as presented in Example 1/C.

The raw product (26.4 g) contained 87% acylated product IV in which

R was 2-ethylhexyl and R' 1-ethyl penthyl. Identification: 13CNMR/ppm: 11.0-38.9 (24C), 42.6 (CHCON) , 43.8 (2 x quaternary C) , 52.9 & 55.0 (2 x N-CH ₂ ), 66.9 & 67.4 (2 x -0-CH ₂ ) , 176.0 & 177.0 & 177.9 (3 x C-0).

1 Example 3

The reaction presented in Item C of Example 1 was repeated, but for acid chloride were used 4.2 g acetyl chloride. The liquid raw product 5 (22.1 g) thus obtained contained 95% of the acetylated product IV (R was 2-ethylhexyl), R' was methyl). Identification: 13CNMR/ppm: 11.8- 38.8 (19C), 43.7 & 44.3 (2 x quaternary C) , 53.4 & 56.9 (2 x N- CH ₂ -), 67.1 & 67.4 (-0-CH ₂ -), 171.9 & 176.6 & 176.9 (3 x C.O) .

^• jC Ex.ample 4

22 g di(2-ethylhexyl)ester III of iminodiacid produced as in Item B of Example 1 and 4.3 g pyridine were dissolved in dry ether. In the mixture 5.3 g acetic acid anhydride were added at room temperature, -|5 whereafter the reaction mixture was made to be refluxed at the boiling point of the ether for 5 hours. The reaction mixture was washed and treated further as presented in Item 1/C. The raw product thus obtained contained 27% acetylated diester IV (R was 2-ethylhexyl, R' was methyl) and 72% non-reacting starting material.

20

Example 5

An N-benzoyl derivative of the di(2-ethylhexyl) of iminodiacid was prepared in the manner described in Example 3, with the exception 25 that the acetyl chloride was substituted by 7.3 g benzoylchloride. The yield of the yellowish oily raw product was 26 g containing 23.9 g of the desired product.

Identification: 13CNMR/ppm: 10.9-38.8 (18C) , 44.4 (2 x quaternary 30 C), 52.8 & 58.1 (2 x N-CH ₂ -), 67.4 (2 x -0-CH ₂ -), 127.8 & 128.4 & 128.9 & 136.7 (2+2+2+1 arom. C) , 173,8 & 176,6 (3 x C=0) .

Example 6

35 The di(2-ethylhexyl)-ester III of iminodiacid (22 g) obtained as described in Item B of Example 1 was cooled to 0°C, whereafter 36 g of 10% NaOH solution were added. In the period of about 15 min 8.5 g

benzoyl chloride were added at such rate that the temperature did not rise above 0°C. After the addition, the mixing was continued at 0°C for 0.5 hour, whereafter the reaction mixture was allowed to be warmed slowly to room temperature. Finally, the reaction mixture was extracted in ether and the organic phase was washed to be neutral with water. The dissolvent was evaporated. The raw product contained 77% benzoylated diester IV in which R was thus 2-ethylhexyl and R'was phenyl. In addition, from the raw product 22% non-reacting starting material were analyzed.

1C

Example 7

22 g of di(2-ethylhexyl)ester III of iminodiacid, produced as in Item B of Example 1, and 8.8 g ethyl chloride acetate were refluxed

^■ |5 in nitrogen atmosphere for 5.5 hours, whereafter the excess of ethyl chloride acetate was distilled off in the form of azeotropic mixture with xylene. According to the gas chrom tograph, 35% of the diester of iminodiacid had reacted into an N-ethoxy carbonylmethyl-substit- uted product V (R was 2-ethylhexyl, R' ' ethoxycarbonyl methyl). 0 Identification: MS spectrum: m/e 528 (M+l) , 454, 328, 216, 116, 57.

Example 8

Item A 5

As in Item B of Example 1, dioctyl ester III of iminodiacid (R was n-octyl) was prepared using 220 g n-octanol instead of 2-ethylhexanol as starting materials. The product was distilled at vacuum, the b. p. 200 to 210°C/2.0 mbar. The yield was 154.4 g (68% from the 0 theoretical quantity) .

Item B

An N-octanoyl derivative IV of dioctyl ester of iminodiacid (R = N- 5 octyl and R' - n-heptyl) was prepared as in Item C of Example 1 starting with the product obtained in the manner described in Item A of Example 8 and with n-octanoyl chloride. The yield and the purity

1 of the product were equivalent to the yield of Item C of Example 1.

Identification: GC: m/e 568 (M+l) .

5 Examples 9-11

From the dioctyl ester of iminodiacid (22 g) obtained as in item A of Example 8 N-2-ethylhexanoyl derivative, N-acetyl derivative and N-benzoyl derivative were preppared as in Examples 2-3 and 5. The ^■ JC products are oily and are produced with 85 to 91% yields.

Identification:

Compound IV in which 15 R was n-octyl and Rl 1-ethylpentyl: m/e 568 (M+l) R was n-octyl and R' methyl: m/e 484 (M+l) R was n-octyl and R' phenyl: m/e 546 (M+l)

The production results of the N-acylated or N-alkylated derivatives 20 IV or V of iminodiacid diesters III accomplished as in the above Examples 1/C - 7 and 8/B - 11 are aseembled in Table 1.

25

30

35

Table 1

Starting materials

Example Starting material Catalyst/ Product IV/V Yield/ III in which R is R'CO and R"X in which R'/R" is %

Certain compounds having structures IV and V were tested in PVC applications. For instance, the ester IV of iminodic acid in which R' was n-octyl and R' was n-heptyl were found to act as a PVC plasticizer equivalent to dioctylphtalate. Equally acted also the N-

acetylated derivative of di(2-ethylhexyl)ester (IV in which R was 2- ethylhexyl and R' was methyl) and the N-benzoylated derivative of di(2-ethylhexyl)ester (IV in which R was 2-ethylhexyl and R' was phenyl) .

The compounds in which R was an alkyl and R' was H. alkyl or phenyl were found to exert a synergetic effect when they were used together with Cd/Zn stabiliser. This fact is seen in VDE values gathered in Table 2, indicating the thermal stability (thermal stability values are defined according to VDE standard 0209 (3.69).

Table 2

1) A — III in which R was 2-ethylhexyl and R' was H

B - III + IV (1:1) in which R was 2-ethylhexyl and

R' was H or 1-ethylpentyl C - IV in which R was n-octyl and R' was 1-heptyl D — IV in which R was n-octyl and R' was 1-heptyl E — IV in which R was 2-ethylhexyl and R' was phenyl