CS271981B1 - 1-/2,2,6,6-tetramethyl-4-piperidyl/-2-propanol and method of its preparation - Google Patents

Abstract

The solution relates to 1- (2,2,6,6-tetramethyl-4-piperidyl) -2-propanol and methods its preparation by hydrogenation of 2,2,6,6-tetramethyl-4-piperidylideneacetone, / 2,2,6,6 tetramethyl-4-piperidinylidene / 2-propanol or / 2,2,6,6-tetramethyl-4-piperidyl] - 2-propanone in an organic solvent environment at 20 ° C to 180 ° C and a hydrogen partial pressure of 0.5 to 25 MPa, in the presence of a hydrogenation catalyst, for 0.5 to 24 h, or by reaction / 2,2,6,6-tetramety1-4-piperidy1 / 2-propanone and a reducing agent from the group complex hydrides and alkali metals in an organic solvent environment 0 to 120 ° C, for i to 10 n. 1- / 2,2,6,6-tetramethyl-4-piperidy1 / 2-propanol it can be used as an intermediate for producing polymer light stabilizers and biologically active substances, including drugs.

Description

The invention relates to 1- (2,2,6,6-tetramethyl-4-piperidyl) -2-propanol of the formula I

(I) and the method of its preparation. 1- / 2,2,6,6-Tetramethyl-4-piperidyl-4-propanol is an intermediate for the preparation of high performance light stabilizers for polymers and biologically active substances, including drugs.

2,2,6,6-Tetramethyl-4-piperidinol is known from the literature (DE 2754 113, CS 236 437) and from industrial practice as a major intermediate for the production of a wide range of esters, diesters and polyesters, which represent an important group of light stabilizers for polymers. type of sterically shielded amines. It is prepared by reduction of 2,2,6,6-tetramethyl-4-piperidone (triacetonamine) with complex hydrides or by its catalytic hydrogenation. Also known is 2- (2,2,6,6-tetramethyl-4-piperidyl) -1-ethanol, which is prepared from triacetonamine by a three-step synthesis via 2,2,6,6-tetramethyl-1,2 ₍ 5, 6-tetrahydropyridine-4-acetate (Chim. Geterocycl. Soedin. 1971, 7/2 / 230-4).

A new tetramethylpiperidine derivative, 1- (2,2,6,6-tetramethyl-4-piperidyl) -2-propanol of formula I and methods for its preparation have now been identified. The first consists in the catalytic hydrogenation of 2,2,6,6-tetramethyl-4-piperidylideneacetone, [2,2,6,6-tetramethyl-4-piperidylidene] -2-propanol or [2,2,6,6-tetramethyl] acetone. 4-piperidyl / 2-propanone in an organic solvent, at a temperature of 20 ⁰ to 180 ° C and a hydrogen partial pressure of from 0.5 to 25 bar, in the presence of a hydrogenation catalyst, for 0.5 to 24 hours. Examples of hydrogenation catalysts that can be used are Raney-Nickel, Ni / Al ₂ O ₃ , Nl / Cr ₂ O ₃ , Pd / C, Pd / BaSO ₄ , Pt / C, Pt / Al ₂ O ₃ , PtO ₂ , or others. . The second process for the preparation of 1- (2,2,6,6-tetramethyl-4-piperidyl) -2-propanol is based on the reaction of [2,2,6,6-tetramethyl-4-piperidyl] -2-propanone with a reducing agent. in an organic solvent medium, at a temperature of 0 ° C to 120 ° C, for 1 to 10 hours. As the reducing agent, it is possible to use a complex hydride, for example LiAlH, Na BH ^, NaAlH ₂ / 0CH ₂ CH ₂ 0CH _3/2 or an alkali metal, e.g. sodium or potassium metal. In the case where a complex hydride is used as a reducing agent, the reaction is carried out at a temperature of 0 ° C to 100 ° C. If an alkali metal is used, the reaction is carried out in a C 1 to C ₄ alcohol environment, at a temperature of 40 ° C to 120 ° C.

The 1- (2,2,6,6-tetramethyl-4-piperidyl) -2-propanol of the formula I according to the invention can be used as an intermediate for the production of light stabilizers suitable for thermoplastic polymeric substrates such as polyolefins, polyesters, polyethers, polyurethanes, polystyrenes, or others. It is also a suitable intermediate for the production of biologically active substances, including drugs.

The following examples illustrate but do not limit the scope of the invention.

CS 271981 Bl

Example 1

19.5 g (0.1 mol) of 2,2,6,6-tetramethyl-4-piperidylideneacetone were introduced into a 100 ml autoclave, 45 ml of 2-propanol and 1.0 g of Raney nickel were added. After closing the autoclave, the reaction zines were purged with hydrogen, heated to 180 DEG C. and heated at 25 MPa with stirring for 0.5 h. After completion of the reaction, the reaction mixture was cooled to room temperature, the catalyst was filtered off, and after distilling off the solvent, the crude product was crystallized from n-hexane. 1- (2,2,6,6-tetramethyl-4-piperidyl) -2-propanol was obtained as a white crystalline product, m.p. 79.5-81 ° C.

Elemental analysis for ^C ₁₂ ^H 25 ^{NO 3} (Mr = 199.340);

Calculated; 72.31% C, 12.64% H 7.03% N

Found: 72.23% C 12.57% H 7.06% N

IR spectrum, solution in CC1 ₄ ·

3630 / page / - / oH / free 3450 / page / - / o _H / vi _a2 .; 2935,2845,

2885 (8) - Q (CH); ^{1340 1375} ( ^s ) - <^ / cH /; 1280 / page / - / 0-0 /; 1410/81 / - Q _{/ c} _ _{n /:} cm-1 ¹ H - NMR spectrum, 10% solution in COCl ₃ :

3.87 / m / -> CH - 0/1 H / *, 1.16 / d / - H ₃ C - CH '- / 3 H /',

1.14 - 1.05 (d) - gem. _CH3 / 12 H /;

2.33-0.33 (m) --CH2 *, -CH NH-ring *, -OH; -CH ₂ - CH C / 9H / i / PP ^m _7

Example 2

39.0 g (0.2 mol) of 2,2,6,6-tetramethyl-4-piperidylideneacetone were introduced into a 250 ml autoclave, 100 ml of methanol and 2.5 g of Ni / Al ₂ O ₃ , containing 45% Ni. After sealing, the autoclave was purged with hydrogen, heated to 60 ° C and heated at 6.0 MPa with stirring for 12 h. after completion of the reaction, the reaction mixture was cooled to room temperature, the catalyst was filtered off, and after distilling off the solvent, the crude product was distilled off under reduced pressure to collect a fraction 72-74 ° C / 400 Pa, from which 1- / 2,2,6 was isolated. 6-tetramethyl-4-piperidyl] -2-propanol.

Elemental analysis for ^c ₁₂ ^H 25 ^N0:

Calculated: 72.31% C

Found: 72.18% C

12.64% H 7.03% N

12.47% H 7.11% N

IR and ¹ H-NMR spectrum the same as in Example 1.

Example 3

19.7 g (0.1 mol) of (2,2,6,6-tetramethyl-4-piperidylidene) -2-propanol are introduced into a 100 ml autoclave, 45 ml of cyclohexane and 0.1 g of Pt on active ingredient are added. coal

CS 271981 B1 with a platinum content of S%. After sealing, the autoclave was purged with hydrogen, heated to ° C and heated at 0.5 MPa with stirring for 24 h. after completion of the reaction, the reaction mixture was cooled to room temperature, the catalyst was filtered off, and after distilling off the solvent, the crude product was recrystallized from n-pentane. 1- (2,2,6,6-tetramethyl-4-piperidyl) -2-propanol was obtained as a white crystalline solid, m.p. 79-80.5 ° C.

Elemental analysis for C 12 ^H 25 ^NO! calculated: 72.31% C 12.64% H 7.03% N

Found: 72.21% C 12.53% H 7.08% N

IR and 1 H-NMR spectra the same as in Example 1.

Example 4

19.7 g (0.1 mol) of (2,2,6,6-tetramethyl-4-piperidyl) -2-propanone were introduced into a 100 ml autoclave, 45 ml of ethanol and 0.2 g of Pd on BaSO 4 were added. ₄ with a palladium content of 5%. After sealing, the autoclave was purged with hydrogen, heated to 180 ° C and heated at 25 MPa with stirring for 0.5 h. After completion of the reaction, the reaction mixture was cooled to room temperature, the catalyst was filtered off, and after distilling off the solvent, the crude product was crystallized from diethyl ether. 1- (2,2,6,6-Tetramethyl-4-piperidyl) -2-propanol was obtained as a white crystalline solid, m.p. 79.5-80.5 ° C. The 1 H-NMR and IR spectra are the same as in Example 1.

r

Example 5

39.4 g (0.2 mol) of (2,2,6,6-tetramethyl-4-piperidyl) -2-propanone were introduced into a 250 ml autoclave, 90 ml of n-heptane and 0.05 g of PtO were added. ₂ · After sealing, the autoclave was purged with hydrogen and the reaction mixture was stirred at 20 ° C and 0.1 MPa for 24 h. After completion of the reaction, the catalyst was filtered off, and after evaporation of 50 ml of n-heptane, the product 1- (2,2,6,6-tetramethyl-4-piperidyl) -2-propanol crystallized as a white crystalline substance with a melting point of 79.5 g. - 81 ° C.

Elemental analysis for C, H, _the "_N0:

1Z zo

Calculated: 72.31% C 12.64% H 7.03% N

Found: 72.25% C 12.59% H 7.09% N 1 H-NMR and IR spectra as in Example 1.

Example 6

To a stirred suspension of 7.6 g (0.2 mol) of lithium aluminum hydride in 500 ml of anhydrous diethyl ether at 0 ° C was added dropwise 39.4 g (0.2 mol) of 2,2,6,6-tetramethyl- 4-piperidyl / -2-propanone for 1 h. The reaction mixture was stirred at 5 ° C for 4 h and at diethyl ether at reflux for 5 h. After completion of the reaction, the reaction mixture was cooled to 0 ° C, and the product complex was quenched with water. The resulting precipitate was filtered off and washed with diethyl ether. after separating the aqueous layer, the ether layers were combined, dried over anhydrous Na ₂ SO ₄ and the diethyl ether was evaporated.

The crude product was crystallized from n-hexane. 1- (2,2,6,6-Tetramethyl-4-piperidyl) -1-propanol was obtained as a white crystalline solid, m.p. 80-81 ° C.

CS 271981 Bl

Elemental analysis for C. _o H _o ^ NO: 12 25 calculated: 72.31% C 12.64% H 7.03% N

Found: 72.27% C 16.61% H 7.06% N 1 H-NMR and IR spectrum as in Example 1.

Example 7

To a suspension of 7.4 g (0.2 mol) in 140 g of diglyme was added 19.7 g (0.1 mol) of [2,2,6,6-tetramethyl-4-piperidyl] -2-propanone at room temperature. and the reaction mixture was heated at 100 ° C for 1 h with stirring. after completion of the reaction, the reaction mixture was cooled, and the resulting complex was quenched with 5% NaHCO ₃ solution. The aqueous layer was separated and extracted with n-hexane. After drying the organic portion over anhydrous Na ₂ SO ₄ , the solvents were distilled off and the crude product was distilled off under reduced pressure to take a fraction of 69-71 ° C / 300 Pa. 1- [2,2,6,6-tetramethyl-4-piperidyl] -2-propanol was obtained as a white crystalline solid, m.p. 79-81 ° C.

Elemental analysis for C H NO: 12 2o

Calculated: 72.31% C 12.64% H 7.03% N

Found: 72.09% C 12.51% H 7.11% N _y 1

IC- and 1 H-NMR spectra as in Example 1.

Example 8

To a solution of 19.7 g (0.1 mol) of (2,2,6,6-tetramethyl-4-piperidyl) -2-propanone in 300 ml of methanol at room temperature was added in small portions 11.5 g (0, 5 moles) of sodium metal. The reaction mixture was stirred at 40 ° C for 10 h. after completion of the reaction, the reaction mixture was cooled to 5 ° C, and the complex was quenched with water. The methanol was distilled off from the reaction mixture, the product from the aqueous layer extracted with n-heptane and dried with anhydrous Na ₂ S0 _{4 <filter-Na 2} SO ₄ 1- / 2,2,6,6-tetramethyl-4-piperidyl / -2 -propanol was isolated by crystallization as a white crystalline product, m.p. 79-80.5 ° C.

Elemental analysis for C 11 H 11 NO 2: 12 calculated: 72.31% c 12.64% H

7.03% N

Found: 72.23% C 12.53% H 7.10% N

IR and ¹ H-NMR spectra as in Example 1.

Example 9

To a solution of 39.4 g (0.2 mol) of (2,2,6,6-tetramethyl-4-piperidyl) -2-propanone in 500 ml of n-butanol at room temperature was added portionwise 23.0 g (1 mol) of sodium metal and the reaction mixture was stirred at 120 ° C for 1 h. After completion of the reaction, the reaction mixture was cooled to room temperature, and the complex was quenched with water. The aqueous layer was separated after salting out the entire amount of n-butanol Naci. The n-butanol solution was dried over anhydrous Na ₂ SO _4. After filtering off the Na ₂ SO ₄ , the solvent was distilled off and the crude product was rectified under reduced pressure to take a fraction of 68-71 ° C / 300 Pa. 1- (2,2,6,6-Tetramethyl-4-piperidyl) -2-propanol was obtained as a white crystalline solid, m.p. 71-80.5 ° C.

CS 271981 Bl

Elemental analysis for 0 ^ 2 ^ 25 ^ ° ^: Calculated: 72.31% C 12.64% H 7.03% N

Found: 72.20% C 12.51% H 7.09% N

IR and ¹ H-NMR spectrum as in Example 1.

Claims (5)

BEFORE THE MET OF THE INVENTION 1- (2,2,6,6-Tetramethyl-4-piperidyl) -2-propanol of the formula I (I) 2. A process for the preparation of 1- (2,2,6,6-tetramethyl-4-piperidyl) -2-propanol according to item 1, characterized in that 2,2,6 ₍ 6-tetramethyl-4-piperidylideneacetone) is prepared. 2,2,6,6-tetramethyl-4-piperidilidene [-2-propanol] or [2,2,6,6-tetramethyl-4-piperid] lidene] -2-propanone is subjected to hydrogenation in an organic solvent medium at a temperature of 20 ⁰ to 180 ° C and a hydrogen partial pressure of 0.5 to 25 MPa, in the presence of a hydrogenation catalyst, for 0.5 to 24 h. 3. A process for the preparation of 1- (2,2,6,6-tetramethyl-4-piperidyl) -2-propanol according to claim 1, characterized in that (2,2,6,6-tetramethyl-4-piperidyl) The β-propanone is treated with a reducing agent in an organic solvent medium, at a temperature of ⁰ to 120 ° C, for 1 to 10 hours. 4. The process according to item 3, characterized in that a complex hydride is used as a reducing agent and the reaction is carried out at a temperature of ⁰ to 100 ° C. 5. The process according to item 3, characterized in that an alkali metal is used as the reducing agent and the reaction is carried out in a medium c. to c. alcohol, at a temperature of ⁰ to 40