CS212509B1 - 1-methakryloyl-2,2,6,6-tetramethyl-4-oxopiperidin and method of prepearing the same - Google Patents

Description

The preparation of this compound is based on the reaction of 2,2,6,6-tetramethyl-4-oxopiperidine with methacrylic acid chloride.

This compound can itself serve as a light stabilizer over polymers. The presence of an active unsaturated group in the molecule of said compound ranks it as a potential monomer for the preparation of polymeric light stabilizers. In such a case, the physical losses of the stabilizer from the polymer would be eliminated by evaporation or extraction, which is an accompanying feature when using low molecular weight derivatives as polymer stabilizers.

According to the invention, this compound can be prepared directly from methacrylic acid chloride and 2,2,6,6-tetramethyl-4-oxopiperidine in excess of the first component or from a solution of dry organic solvents such as benzene, toluene, aliphatic and alicyclic hydrocarbons and others. Preferably, organic bases such as triethylamine or pyridine may be used to bind the hydrogen chloride released in the reaction.

Example 1

1.55 g of 2,2,6,6-tetramethyl-4-oxopiperidine and 5.2 g of methacrylic acid chloride were charged to a flask equipped with a stirrer, nitrogen inlet and outlet. Under an inert atmosphere, the mixture was stirred at room temperature for 2 hours. Excess acid chloride was then distilled off in vacuo. The residue was dissolved in aqueous sodium hydroxide and the product was extracted with ether. After the ether was distilled off and recrystallized from heptane, white crystals of m.p. = 115-117 ° C were obtained.

Elemental analysis for

Calculated: C 69.96%, H 9.42%, N 6.28%;

Found: C 69.18%, H 9.42%, N 6.60%.

NMR (CDCl 3) δ 6.38 m (1H), 5.82 m (1H), 2.98 and (4H), 2.38 s (3H), 1.80 s (12H)

IR (CC1 _4)? Max = 3000, 1740, 1652, 55- 1, 1469, 1380, 1330, 1310, 1270,

240, 1050, 1090, 940 cm -1.

Example 2

To a flask equipped with a heating, stirrer, reflux condenser, nitrogen inlet and outlet and dropping funnel was charged 1.55 g of 2,2,6,6-tetramethyl-4-oxopiperidine, ml of benzene and 5 ml of triethylamine. After heating to boiling, a solution of 1.2 g of methacrylic acid chloride in 5 ml of benzene was added dropwise with stirring over 0.5 hour. The mixture was then allowed to react for a further 2 hours. After cooling, the crystalline material was filtered off.

The white liquor was evaporated to dryness under reduced pressure, and crystallized from heptane to give a white crystalline product, m.p. = 115-117 ° C.

Example 1 and d 3

100 wt. parts of polypropylene were mixed with 0.15 wt. The mixture was homogenized in a Brabender plastograph at 180 ° C for 10 minutes. Films 0.1 mm thick were pressed from the homogenized mixture at 190 ° C and 20 MPa for 5 minutes. The foils were irradiated with a 125 W mercury lamp at 7 cm from the source. The degradation of the polymer was monitored by the development of a hydroperoxide and carbonyl band. While the time of reaching the carbonyl index of 0.2 for pure polypropylene was 150 hours, the stabilized polymer reached this value after 1200 hours.

Claims (2)

OBJECT OF THE INVENTION 1. 1-Methacryloyl-2,2,6,6-tetramethyl-4-oxopiperidine of the formula 2. A process for the preparation of 1-methacryloyl-2,2,6,6-tetramethyl-4-oxopiperidine according to claim 1, characterized in that 2,2,6,6-tetramethyl-4-oxopiperidine is treated with acid chloride of methacrylic acid in a hydrocarbon solvent in the presence of a base at temperatures from room temperature to the boiling point of the reaction mixture.