Academic literature on the topic '1-Methylnaphtalene'

The 1-[N-(methyl)-(3,5-dimethylphenylamino)]methylnaphthalene (chemical formula C20H21N) was prepared by means of a condensation between alpha-naphthylaldehyde and 3,5-dimethylaniline in anhydrous ethanol to obtain the aldimine (1) which was reduced with NaBH4 to afford the 1-[N-(3,5-dimethylphenylamino)]methylnaphtalene (2), and finally, the compound (3) was obtained by N-alkylation reaction of (2) with methyl iodine (CH3I) and potassium carbonate (K2CO3) in acetone. Final compound (3) was purified by chromatographic column. The XRPD pattern for the new compound, 1-[N-(methyl)-(3,5-dimethylphenylamino)]methylnaphthalene, was obtained. This compound crystallizes in monoclinic system with space group P21/a (No. 14) and refined unit-cell parameters a=13.260(4) Å, b=15.495(5) Å, c=7.719(5) Å, β=90.19(6), and V=1586(1) Å3.

The present study aims at the isolation and identification of diverse phenolic polyketides from Aloe vera (L.) Burm.f. and Aloe plicatilis (L.) Miller and includes their 5-LOX/COX-1 inhibiting potency. After initial Sephadex-LH20 gel filtration and combined silica gel 60- and RP18-CC, three dihydroisocoumarins (nonaketides), four 5-methyl-8-C-glucosylchromones (heptaketides) from A. vera, and two hexaketide-naphthalenes from A. plicatilis have been isolated by means of HSCCC. The structures of all polyketides were elucidated by ESI-MS and 2D 1H/13C-NMR (HMQC, HMBC) techniques. The analytical/preparative separation of 3R-feralolide, 3′-O-β-d-glucopyranosyl- and the new 6-O-β-d-glucopyranosyl-3R-feralolide into their respective positional isomers are described here for the first time, including the assignment of the 3R-configuration in all feralolides by comparative CD spectroscopy. The chromones 7-O-methyl-aloesin and 7-O-methyl-aloeresin A were isolated for the first time from A. vera, together with the previously described aloesin (syn. aloeresin B) and aloeresin D. Furthermore, the new 5,6,7,8-tetrahydro-1-O-β-d-glucopyranosyl- 3,6R-dihydroxy-8R-methylnaphtalene was isolated from A. plicatilis, together with the known plicataloside. Subsequently, biological-pharmacological screening was performed to identify Aloe polyketides with anti-inflammatory potential in vitro. In addition to the above constituents, the anthranoids (octaketides) aloe emodin, aloin, 6′-(E)-p-coumaroyl-aloin A and B, and 6′-(E)-p-coumaroyl-7-hydroxy-8-O-methyl-aloin A and B were tested. In the COX-1 examination, only feralolide (10 µM) inhibited the formation of MDA by 24%, whereas the other polyketides did not display any inhibition at all. In the 5-LOX-test, all aloin-type anthranoids (10 µM) inhibited the formation of LTB4 by about 25–41%. Aloesin also displayed 10% inhibition at 10 µM in this in vitro setup, while the other chromones and naphthalenes did not display any activity. The present study, therefore, demonstrates the importance of low molecular phenolic polyketides for the known overall anti-inflammatory activity of Aloe vera preparations.

AbstractThe unsupported catalysts were obtained during hydrogenation by in situ high-temperature decomposition (above 300 °C) of water-soluble metal precursors (ammonium molybdate and nickel nitrate) in water-in-oil (W/O) emulsions stabilized by surfactant (SPAN-80) using elemental sulfur as sulfiding agent. These self-assembly Ni–Mo sulfide nanosized catalysts were tested in hydrogenation of aromatics under CO pressure in water-containing media for hydrogen generation through a water gas shift reaction (WGSR). The composition of the catalysts was determined by XRF and active sulfide phase was revealed by XRD, TEM and XPS techniques. The calculations based on TEM and XPS data showed that the catalysts are highly dispersed. The surfactant was found to affect both dispersion and metal distribution for Ni and Mo species, providing shorter slab length in terms of sulfide particle formation and stacking within high content of NiMoS phase. Catalytic evaluation in hydrogenation of aromatics was performed in a high-pressure batch reactor at T = 380–420 °С, p(CO) = 5 MPa with water content of 20 wt.% and CO/H2O molar ratio of 1.8 for 4–8 h. As shown experimentally with unsupported Ni–Mo sulfide catalysts, the activity of aromatic rings depends on the substituent therein and decreases as follows: anthracene>>1-methylnaphthalene≈2-methylnaphthalene>1,8-dimethylnaphthale-ne>>1,3-di-methylnaphthalene>2,6-dimethylnaphthalene≈2,3-dimethylnaphthalene>2-ethyl-naphthalene. The anthracene conversion reaches up to 97–100% for 4 h over the whole temperature range, while for 1MN and 2MN it doesn’t exceed 92 and 86% respectively even at 420 °С for 8 h. Among dimethyl-substituted aromatics the higher conversion of 45% was achieved for 1,8-dimethylnaphthalene with 100% selectivity to tetralines at 400 °С for 6 h. Similar to 1- and 2-methylnaphtalenes, the hydrogenation of asymmetric dimethyl-substituted substrate carries out through the unsubstituted aromatic ring indicating that steric factors influence on the sorption mechanism over active metal sites. The catalysts were found to be reused for at least six cycles when the hydrogenation is sulfur-assisted preventing metal oxide formation. It was established, that at the first 2–3 h known as the induction period, the oxide catalyst precursors formed slowly by metal salt decomposition, which reveals that it is the rate-determining step. The sulfidation is rather fast based on high catalytic activity data on 2MN conversion retaining at 93–95% upon recycling.

In this report, modifications and experimental tests with an early stage test rig intended for producing a commercial solution to fractionating pyrolysis oil are described. The idea is to use centrifugal force to separate the formed aerosols from condensible gases with a lower volatility. A stacked disc centrifuge prototype built to work at high temperature was used. The experiment was done with a single component, 1-Methylnaphtalene (1-MN) to evaluate the functionality of the test rig. No separation was achieved, concluding that further work need to be done at different operating parameters with 1-Methylnaphtalene prior to including more components. The reason for the negative separation result is probably due to that the saturation ratio was to low resulting in that no aerosol was formed during the experiments. Further work includes improving the stability of the inlet stream to the centrifuge. Perform more experiments with other process parameters, recommendation is to decreasing the temperature at the inlet to the centrifuge to increase the saturation ratio. It is also suggested that an optical in situ measuring devise is added to the test rig to facilitate operation.