SU690015A1 - 2-(pyridyl-3-methoxy)-4-methyl(phenyl)-3,4-dihydropyranes as antiaging agents of light rubbers - Google Patents

Description

An analysis of the IR spectrum of 2- (pyridyl-3-methoxy) -4-methyl-3, 4-di-propyran shows no aldehyde groups, bands appear in the 1114 region, characteristic of C-O-C vibrations in the pyran cycle. Frequency 1225 refers to vibrations of the C-O-C ether group (oxygen between cycles). The intense absorption band in the 1654 cm region indicates the existence of a double carbon – carbon bond in the pyran ring. The valent oscillations of the groups and CH, pyran cycle are characteristic of CH and CH in the region 2850, with frequencies of 2940 cm. Oxygen atom the linking pyridine and dihydropyran ring, together with the oxygen of the ring, forms an acetal group, the oscillations of which occur in the spectrum in the form of a broad band at 10251060 cm. Oscillation frequencies in the region of 1580, 1590 and 1430 cm are characteristic of the pyridine cycle. The infrared spectrum was obtained on a UR-20 instrument in the region of 500–300 cm in a micro-slide. The PMR spectrum indicates the presence of a mixture of n-A stereoisomers, Nze, 6 N 11 cis: trans (60: 40%). There are two doublets of CHj-groups l / 1.0 ppm; two H2 signals: 5.00 m. (triplet). ЗтJj 2,5 Hz and 4,92 m ЧгНз Hz; T, (quartet), 1., 2.5 6.5 Hz. CHj -rpynn signal as a multiplet at 4.6 ppm; H forms a multiplet at 4.6 ppm, and two quartets at, 0 ppm. The signals of the protons of the pyridine ring: HiH 7.55 MD, Hg 7.61 MD, H 7.18 MD. There is a wide multiplet in the region of 1.0-2.5 ppm. belonging to 2Nz and N. The PMR spectrum was taken on a BS 487 V spectrometer, CCE was used as a solvent, hexamethyldisiloxane was used as an internal standard. Chemical shifts in ppm are measured on the S scale. Example 2. 2- (Pyridyl-3-methoxy) -4-phenyl-3, 4-dihydro9Iran. The equimole mixture of 3-vinyloxymethylpyridine and cinnamon aldehyde is heated to 190-195 ° C and held for 15 hours. 2- (pyridyl-3-methoxy) -4-phenyl-3, 4-dihydropyran is isolated as a viscous liquid . 169 Po2O 171 ° / 1mm; p, 1.5715; d 1,1358. Yield 43%. Found,%: C 76.5; H 6.4 N 5.2; T 77.40; N02 Calculated: C 76.4; H 6.4; N 5.2; MRD 77.27. Similarly to the previous example, the structure of 2- (pyridyl-3-methoxy) -4-phenyl-3, 4-dihydropyran was confirmed. Example 3. The protective effect of 2- (pyridyl-3-methoxy) -4-methyl-3, 4-dihydropyran in light rubber with light-ozone and ozone aging. In the rollers, a rubber mixture is prepared in the usual way (rubber 1 and 2 ) and the mode of vulcanization are given in table. 1. As an antioxidant, 2- (pyridyl-3-methoxy) -4-methyl-3 was used. 4-dihydropyran in the amount of 1.0-5.0 parts per 100 weight parts rubber Table

690015b

Continuation of ta5n.1

The aging of rubbers was carried out in a jipH static light chamber, 10% and 20% tensile rubber deformation and 0.0005% q6. Ozone concentration in air, and 10% static ozone deformation zone and 0.0003% ozone concentration in air about. Determine the time from the beginning of the exposure of rubber to the start of cracking ().

The results of the determination of the protective effect of 2- (pyridyl-3-methoxy) -4-methyl (phenyl) -3,4-dihydropyranes in PC-based rubber and SKI-3 in light-ozone and ozone aging in comparison with NG-2246 are given in tab. 2.2- (Pyridyl-3-methoxy) -4-methyl-3, 4-dihydropyran proved to be a highly effective antioxidant in comparison with the known NG-2246.

20

10 1.0 1.0

2.8 1.8

3.5 2.0

A change in the color of rubber during light aging was observed in the chamber

35 ° C in

Xenotest

flow

at

100 h and visual observation of samples subjected to both atmospheric aging and aging in the light-ozone chamber.

In the presence of 2- (pyridyl-3-methoxy) -4-methyl-3, 4-dihydropyran as an antioxidant, the color of rubber during the aging process remained almost unchanged.

Similarly, 2- (pyridyl-3-methoxy) -4-phenyl-3,4-dihydropyran was tested. This substance turned out to be even more effective as an antioxidant of light rubber. The test results are shown in Table. 2

Table 2

20

10 1.0

20 1.0

10 1.0 1.0

4.03.44.0 1.3

1.2

5.15.0 1.8

2.0

Thus, new chemical substances - 2- (pyridyl-3-methoxy) -4-methyl (phenyl) -3,4-dihydropyranes are illi high efficacy in quality and coloring, against antioxidants with ethylmx P (can be used in 1 preparation of products G of light rubber.

Claims (2)

Q invention 2- (Pyridyl-3-methoxy) -4-methyl (phenyl) -3,4-dihydropyran of the general formula h, oh) but where R is methyl or phenyl, as antioxidants of light rubber. Information sources, taken into account in the examination 1. Auxiliary substances for polymeric materials. M., Himi 1966. 2. US patent; No. 2538355, cl. 260.45.95, 1951.