CS259396B1 - 1,2,2,6,6-pentamethyl-4-(delta-bromalkoxy) piperidines and method of their preparation - Google Patents

Abstract

The solution relates to 1,2,2,6,6-pentamethyl-4- - (? - bromoalkoxy) piperidines of formula I and the process their preparation, which consists in that 1,2,2,6,6-pentamethyl-4-hydroxypiperidine is reacted of formula II with α, ω-dibromoalkane of Formula III with vigorous stirring in heterophasic system, with one phase forming an aqueous alkali hydroxide solution and the species phase generates an organic solvent immiscible with the aqueous phase in the presence of the anionic salt type catalyst temperature range of 10 to 100 ° C. compounds of Formula I are used as light stabilizers for polymers

Description

The present invention relates to 1,2,2,6,6-pentamethyl-4- (n-bromoalkoxy) piperidines and to a method of preparation.

Sterically shielded amines are currently among the most effective light stabilizers for polymers [F. E. Karrer, Makromol. Chem., 181, 595 (1980), F. Gugumus, Developments in Polymer Stabilization-1, ed. G. Scott, Applied Science Publishers, Ondon, 1979, Chap. 8, J. J. Usilton, A.R. Patel, Am. Chem. Soc., Polym. Prep., 18 (1), 393 (1977)].

These are various derivatives of 2,2,6,6-tetramethylpiperidine, 1,2,2,6,6-pentaalkylpiperidine,

2,2,6,6-tetraalkylpiperazine or 7,15-diazadispiro [5,1,5,3] hexadecane. These compounds inhibit undesirable degradation processes that occur in the interaction of light and oxygen with polymers. A disadvantage of this group of light stabilizers is the high volatility and the extractability of low molecular weight polymer derivatives. The compounds of the invention contain functional ω-bromoalkoxy groups in their molecule. The presence of this group in the light stabilizer molecule increases its molecular weight and, in addition, allows for further modifications of the backbone. Such compounds have not been previously described in the literature.

The present invention provides 1,2,2,6,6-pentamethyl-4- (ω-bromoalkoxy) piperidines of the formula I

C ι 'f f ^ 5,

IN

ch ₃

Where n is 2 to 12.

The present invention further provides a process for the preparation of compounds of formula I, characterized in that 1,2,2,6,6-pentamethyl-4-hydroxypiperidine of formula II

is reacted with the ω-dibromoalkane of formula III

Br - (CH ₂ ) n - Br (III) wherein n is 2 to 12, in a heterophasic system, one phase forming an aqueous solution of an alkali hydroxide, preferably potassium hydroxide, in a concentration range of 5 to 70 washes. or sodium hydroxide in a concentration range of 5 to 50% and the other phases form an organic solvent not mixed with the aqueous phase, such as benzene, toluene or xylenes, in the presence of a salt salt type catalyst such as tetrabutylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium hydrogen sulphate or , which is used in an amount of 1 to 10 mol. % to the amount of compound II in the range of 10 to 100 ° C.

EXAMPLE

8.56 g (0.05 mol) of 1,2,2,6,6-pentamethyl-4-hydroxypiperidine, 1.61 g (0.005 mol) of tetrabutylammonium bromide, 9.4 g (0.05 mol) -1, 2-dibromoethane, 10 ml of benzene and 15 ml of 50% sodium hydroxide solution is vigorously stirred for ¹ at room temperature for 30 hours. The organic layer was separated, washed with water and brine, and dried over anhydrous sodium sulfate. The solvent is distilled off and the product is distilled under vacuum. A colorless liquid fraction is collected at a temperature range of 120 to 130 ° C at a pressure of 333 Pa.

Elemental analysis for C _{f 2} H _M BrNO: Calculated:

% C, 51.80;% H, 8.69;% N, 5.03.

% C, 51.38;% H, 8.46;% N, 4.89.

¹ H NMR spectrum (CDCl ₃ ):

.delta. (ppm) =

0.97 (s, - CH ₃ and x, 6H);

1.12 (s, —CH ₃ eq, 6H),

1.23 to 1.93 (m, CH _{2 R} -, 4H);

2.17 (s, _N-CH3, 3H);

3.37 (t, _CH _2-O, 2H, J = 6 Hz);

3.40 (t, —CH _and —Br, 2H, J = 6 Hz),

3.40 to 4.00 (m, = CH-O-, 1H). Example 2

8.56 g (0.05 mol) of 1,2,2,6,6-pentamethyl-4-hydroxypiperidine, 0.34 g (0001 mol) of tetrabutylammonium hydrogen sulphate, 10.80 g (0.05 mol) of 1.4 Dibromobutane, 10 ml of toluene and 15 ml of 30% potassium hydroxide are stirred vigorously at 50 ° C for 20 hours.

Thereafter, the reaction mixture was worked up as in Example 1. A fraction of a colorless liquid was collected by distillation at a temperature range of 130 to 140 ° C at a pressure of 333 Pa.

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Elemental analysis for C ₁₄ H ₂₈ BrNO: Calculated:

% C, 54.90;% H, 9.21;% N, 4.57.

H, 9.25; N, 4.49.

1 H NMR (CDCl ₃ ):

(ppm) -

0.97 (s, —CH ₃ ax, 6H),

1.12 (s, —CH ₃ eq, 6H),

1.23 to 2.00 (m, _--CH2 -, 8H);

2.17 (s, CH-1-N, 3H),

3.37 (t, --OH, i - O -, 2H),

3.40 (t, CH ₂ -Br, 2H);

3.40 to 4.00 (m, = CH-O-, 1H).

Example 3

8.56 g (0.05 mol) of 1,2,2,6,6-pentamethyl-4-hydroxypiperidine, 0.68 g (0.002 mol) of tetrabutylphosphonium bromide, 12.2 g (0.05 mol) of 1.6 Dibromohexane, 10 ml of a mixture of xylenes with a distillation range of 137 to 140 ° C and 10 ml of 60% potassium hydroxide are vigorously stirred at 100 ° C for 8 hours.

Thereafter, the reaction mixture was worked up as in Example 1. A fraction of a colorless liquid was collected by distillation at a temperature range of 180 to 190 ° C at a pressure of 333 Pa.

Elemental analysis for Ο ₁₆ Η33ΒγΝΟ: Calculated:

% C, 57.47;% H, 9.65;% N, 4.19.

H, 10.05; N, 4.11.

Ή NMR Spectrum (CDCl ₃ ):

(ppm) =

0.97 (s, --CH. Ax, 6H),

1.11 (s, —CH ₃ eq, 6H),

1.17 1.93 (m, _-CH2 -, 12 H);

2.15 (s, CH ₃ -N, 3H),

3.35 (t, —CH2 -, -, 2H, J = 6 Hz),

3:39 (t, CH ₂ -Br, 2H, J = 6 Hz);

3.40 to 4.00 (m, = CH - O -, 1H).

Example 4

8.56 g (0.05 mol) of 1,2,2,6,6-pentamethyl-4-hydroxypiperidine, 1.61 g (0.005 mol) of tetrabutylammonium bromide, 13.6 g (0.05 mol) of 1.8 Dibromooctane, 10 ml benzene and 15 ml 15% potassium hydroxide were vigorously stirred at 50 ° C for 20 hours.

Thereafter, the reaction mixture was worked up as in Example 1. A fraction of a colorless liquid was collected by distillation at a temperature range of 185 to 195 ° C at a pressure of 300 Pa.

Elemental analysis for C ₁₈ H ₃₆ BrNO: Calculated:

% C, 59.65;% H, 10.01;% N, 3.87.

H, 10.16; N, 3.70.

1 H NMR spectrum (CDCl ₃ ):

.delta. (ppm) =

0.97 (s, - CH ₃ and x, 6H);

1.12 (s, —CH ₃ eq, 6H),

1.20 to 2.00 (ffl, CH ₃ -, 16 H);

2.17 (s, CH _{3 -} N, 3 H),

3.35 (t, CH ₂ -Ο-, 2H, J = 6 Hz);

3:39 (t, CH ₂ -Br, 2H, J = 6 Hz);

3.40 to 4.00 (m, = CH - O -, 1H).

Example 5

8.56 g (0.05 mol) of 1,2,2,6,6-pentamethyl-4-hydroxyplperidine, 1.61 g (0.005 mol) of tetrabutylammonium bromide 15.0 g (0.005 mol) of 1,10-dibromodecium, 10 ml of benzene and 15 ml of 50% sodium hydroxide are stirred vigorously at room temperature for 30 hours.

Thereafter, the reaction mixture was worked up as in Example 1. A fraction of a colorless liquid was collected by distillation at a temperature range of 190 to 200 ° C at a pressure of 200 Pa.

Elemental analysis for C ₂ < ₁ H ₀ BrNO: Calculated:

% C, 61.52;% H, 10.33;% N, 3.59.

% C, 62.48;% H, 10.90;% N, 3.77.

Ή NMR Spectrum (CDCl ₃ ):

(ppm) =

0.97 (s, —CH ₃ ax, 6H),

1.12 (s, —CH ₃ eq, 6H),

1.17 to 2.00 (m, - _CH2 -, 20 H).

2.17 (s, CH _{3 -} N, 3 H),

3.27 (s, --OH _{2 -} O, 2H, J = 6 Hz),

3.30 (t, CH ₂ -Br, 2H, J = 6.5 Hz);

3.30 to 4.00 (m, = CH - O -, 1H).

Example 6

8.56 g (0.05 mol) of 1,2,2,6,6-pentamethyl-4-hydroxypiperidine, 1.61 g (0.005 mol) of tetrabutylammonium bromide, 16.41 g (0.05 mol) of 1.12 Dibromododecane, 10 ml benzene and 15 ml 50% sodium hydroxide are vigorously stirred at room temperature for 30 hours. Thereafter, the reaction mixture was worked up as in Example 1. A fraction of a colorless liquid was collected by distillation at a temperature range of 195 to 205 ° C at a pressure of 173 Pa.

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Elemental analysis for C ₂₂ H ₄₄ BrNO: Calculated:

% C, 63.14;% H, 10.60;% N, 3.35.

62.10% C, 10.21 θ / ο H, 3.41% N.

1 H NMR (CDCl ₃ ):

.delta. (ppm) =

0.97 (s, CH ₂ and x, 6H);

1.12 (s, —CH, eq, 6H),

1.17 to 1.95 (m, _-CH2 - 24H).

2.17 (s, CH ₃ -N, 3H);

3.27 (t, - CH ₂ - O, 2H, J = 6 Hz);

3.31 (t, CH ₂ -Br, 2H, J = 6.5 Hz);

3.31 to 4.01 (m, --CH - O -, 1H).

Example 7

100 parts by weight of unstabilized powdered polypropylene are impregnated in dichloromethane with 0.1 wt. parts by weight of 2,6-di-tert-butyl-4-methylphenyl, 0.15 wt. % of calcium stearate and 0.2 wt. After evaporation of the solvent, 0 'of 0.2 mm film are pressed from the mixture at 20 MPa at 190 ° C for 3 minutes. The films thus prepared are irradiated with a 125 W mercury lamp at a distance of 7 cm from the source. The degradation of the polymer is monitored by the development of the carbonyl band in the infrared spectra. While the time to reach the carbonyl index of 0.2 for pure polypropylene is 240 hours, the stabilized pool polymer does not reach this value until after 1,560 hours.

Claims (5)

OBJECT OF THE INVENTION 1. 1,2,2,6,6-Pentamethyl-4- (n-bromoalkoxy) piperidines of formula I C f, CH- ₃ wherein n is 2 to 12. 2. A process for the preparation of 1,2,2,6,6-pentamethyl-4- (ω-bromoalkoxy) piperidines of the formula I as defined in claim 1, characterized in that 1,2,2,6,6-pentamethyl-4-hydroxypiperidine of the formula II is reacted with α, ω-dibromoalkane of formula III Br- (CH ₂ ) n - Br (ΠΙ) where n is 2 to 12, in a heterophasic system with vigorous stirring, one phase forming an aqueous solution of alkaline hydroxide and the other phase forming an organic solvent immiscible with the defective phase, in the presence of an onium catalyst salts in a temperature range of 10 to 100 ° C. 3. The method of claim 2, wherein the alkali hydroxide is sodium hydroxide in a concentration range of 5 to 50% or potassium hydroxide in a concentration range of 5 to 70%. 4. The process of claim 2, wherein the water-immiscible organic solvent is benzene, toluene or a mixture of xylenes. Spasohite according to claim 2, characterized in that onium catalysts are used, such as tetrabutylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium hydrogen sulphate or tetrabutylphosphonium bromide in an amount of 1 to 10 moles. % based on the amount of the starting 1,2,2,6,6-pentamethyl-4-hydroxypiperidine.