5672-94-6Relevant articles and documents
Photoreaction of 2-morpholinoacrylonitrile with substituted 1-acetonaphthones. Part II
Memarian,Nasr-Esfahani,Dopp
, p. 476 - 478 (2001)
Photochemical reactions of substituted 1-acetonaphthones in the presence of 2-morpholinoacrylonitrile were investigated. The type of reaction, photocycloaddition vs. photosubstitution, is dependent on the nature of the additional substituent. The location of the additional substituent on the ring also affects the type of addition, [2 + 2] vs. [4 + 2].
Zeolite catalyzed highly selective synthesis of 2-methoxy-6-acetylnaphthalene by Friedel-Crafts acylation of 2-methoxynaphthalene in acetic acid reaction media
Yamazaki, Tomoyoshi,Makihara, Makoto,Komura, Kenichi
, p. 170 - 176 (2016/12/09)
Zeolite catalyzed Friedel-Crafts acetylation of 2-methoxynaphthalene to produce 2-methoxy-6-acetylnaphthalene with high selectivity and conversion has been a challenging task, because the obtained compound is a key intermediate for an anti-inflammatory agent, Naproxen. However, no satisfactory results have been obtained with zeolite catalysts, and harmful solvents have been used to gain a high selectivity together with a high conversion. Here, we report the synthesis of 2-methoxy-6-acetylnaphthalene from 2-methoxynaphthalene with a high selectivity and a high conversion under an unprecedented simple reaction system; acetic anhydride as an acetylating agent, acetic acid as a solvent, and proton-type zeolite catalysts with low acidity. Among the examined zeolites, a proton-type H-MOR (SiO2/Al2O3 = 200) with a low acid content shows a conversion of 82% and an 86% selectivity for 2-methoxy-6-acetylnaphthalene. Further, detailed control experiments using H-MOR catalyst in acetic acid solvent were carried out to propose a plausible reaction mechanism.
Hierarchical ZSM-5 zeolite with uniform mesopores and improved catalytic properties
Serrano,Escola,Sanz,Garcia,Peral,Moreno,Linares
, p. 4206 - 4216 (2016/06/09)
Hierarchical ZSM-5 with uniform mesoporosity was synthesized by the sequential coupling of two strategies: generation of secondary porosity by the crystallization of silanized protozeolitic units and a subsequent treatment with a basic surfactant-containing solution. The ZSM-5 zeolite obtained exhibited high crystallinity and contained two levels of uniform porosities within the micro- and mesopore ranges, respectively. The uniform mesoporosity is the result of the reorganization of irregular mesopores, created initially from the silanized protozeolitic units, via the local rearrangement of zeolitic fragments, and promoted by contact with a cationic surfactant under mild basic conditions. Interestingly, this second treatment was less effective when it is applied to a non-hierarchical ZSM-5 sample, showing that the presence of initial secondary porosity is essential for allowing the surfactant/ammonia solution to modify the zeolite and form uniform mesopores. Characterization of the zeolite samples using different techniques showed that the crystallinity, Al coordination and acidic features of the zeolite do not change significantly after the mesopore narrowing treatment, even though significant variations in the textural properties are observed as expected. The effects of the occurrence of regular mesoporosity on the catalytic properties of the hierarchical ZSM-5 zeolite were proven using the acylation of 2-methoxynaphthalene as a test reaction. The material with uniform mesopores showed both the highest activity and selectivity towards 6-acetyl-2-methoxynaphthalene, which was interpreted as the result of the presence of a more regular and less rough mesopore surface, which in turn facilitated the interaction between the reactant molecules and the active sites located and distributed over the mesopores.
Enhancement in activity and shape selectivity of zeolite BEA by phosphate treatment for 2-methoxynaphthalene acylation
Hodala, Janardhan L.,Halgeri, Anand B.,Shanbhag, Ganapati V.
, p. 90579 - 90586 (2016/10/07)
Pore-engineering of large pores of zeolite BEA by phosphate treatment effectively narrowed the pores with the creation of new acid sites. Phosphate modification of BEA with lower loading was more effective in pore modification without affecting the zeolite structure. Pyrophosphates and polyphosphates are mainly responsible for the narrowing of the zeolite pores. Both the activity and shape selectivity for 2-acetyl-6-methoxynaphthalene were enhanced in the acylation of 2-methoxynaphthalene. At higher concentration of phosphates, conversion and selectivity decreased due to dealumination. 1% P loading was found to be optimum for the acylation of 2-methoxynaphthalene. With the optimized phosphate modification of BEA, high selectivity of 78% to 2-acetyl-6-methoxynaphthalene was achieved with 77% conversion.
Synthesis of bridged biarylbisquinones and effects of biaryl dihedral angles on photo- and electro-chemical properties
Wongma, Krittaphat,Bunbamrung, Nantiya,Thongpanchang, Tienthong
, p. 1533 - 1540 (2016/03/01)
A series of bridged biarylbisquinones, QBINOLs 1-4, and their corresponding monomers, QNaphs 5-6, were designed to demonstrate the influence of biaryl conformation on the photo- and electro-chemical properties of the molecules. All target compounds were synthesized from the Diels-Alder reaction between silyl enol ethers of the corresponding naphthyl or binaphthyl derivatives and p-benzoquinone. Addition of an OMe auxochrome or formation of the dimeric structures affect the absorption spectra and the energy band gap (Eg), but not the reduction potentials of the molecules. Narrowing the dihedral angles of the QBINOLs by shortening methylene bridges limited the contribution of bridging OR auxochromes and therefore resulted in lower HOMO levels and larger Eg.
Acetylation of 2-methoxynaphtalene with acetic anhidryde over Zr4+-zeolite beta
Cahyono, Edy,Priatmoko, Sigit,Haryani, Sri
, p. 79 - 83 (2016/08/25)
Regioselective acetylation of 2-methoxy naphthalene (2-MN) to 2-acetyl-6-methoxy naphthalene (2,6-ACMN) is the important step in the synthesis of pharmaceutical compounds such as (S)-naproxen. The liquid phase acetylation of 2-MN with acetic anhydride over Zr4+-zeolite beta catalyst was investigated under controlled reaction conditions. Catalyst was prepared by ion exchange and impregnation method. Zr4+-zeolite beta(ie) was obtained by ion exchange that done with 0,5 M ZrCl4 then calcined at 550°C for 3 h and Zr4+-zeolite beta(ip) was obtained by impregnation method. Catalytic activity of catalysts was affected by preparing method, temperature, and reaction solvent. Catalyst that prepared by impregnation showed inactive on acetylation of 2-MN. 1-Acetyl-2-methoxynaphtalene (1,2-ACMN), 1-acetyl-7-methoxy-naphtalene (1,7-ACMN), and 2-acetyl-6-methoxy naphthalene (2,6-ACMN) were identified as the products of 2-MN acetylation over Zr4+-zeolite beta(ie) without solvent. Activity and selectivity of Zr4+-zeolite beta(ie) was increased in dichloromethane solvent at 140°C for 36 h, 1,8-ACMN was not identified and ratio of 1,2-ACMN to 2,6-ACMN was 1,6:1.
Synthesis of industrially important aromatic and heterocyclic ketones using hierarchical ZSM-5 and Beta zeolites
Kore, Rajkumar,Srivastava, Rajendra,Satpati, Biswarup
, p. 129 - 141 (2015/09/28)
Hierarchical ZSM-5 and Beta zeolites were investigated in the synthesis of wide range of industrially important aromatic/heterocyclic ketones by Friedel-Crafts acylation and benzoylation reactions. For comparative study, conventional ZSM-5 and Beta, and amorphous mesoporous Al-MCM-41 were investigated. Hierarchical zeolites were prepared by multi-ammonium structure directing agents whereas conventional zeolites were prepared by mono-ammonium structure directing agents. Among the catalysts investigated in this study, hierarchical Beta exhibited the highest reactant conversion in the acylation and benzoylation reactions. In this study, the systematic assessment of the catalytic activity of acid catalysts for wide range of aromatic and heterocyclic compounds is shown under one umbrella. To the best of our knowledge, these reactions over hierarchical zeolites (ZSM-5 and Beta) are reported here for the first time. Structure activity relationship is explained based on the physico-chemical properties, molecular size, reactivity of reactants, and reaction mechanism. Catalysts can be easily recovered and reused with negligible loss in the catalytic activity.
Single-step delamination of a MWW borosilicate layered zeolite precursor under mild conditions without surfactant and sonication
Ouyang, Xiaoying,Hwang, Son-Jong,Runnebaum, Ron C.,Xie, Dan,Wanglee, Ying-Jen,Rea, Thomas,Zones, Stacey I.,Katz, Alexander
, p. 1449 - 1461 (2014/02/14)
Layered borosilicate zeolite precursor ERB-1P (Si/B = 11) is delaminated via isomorphous substitution of Al for B using a simple aqueous Al(NO 3)3 treatment. Characterization by PXRD shows loss of long-range order, and TEM demonstrates transformation of rectilinear layers in the precursor to single and curved layers in the delaminated material. N 2 physisorption and base titration confirm the expected decrease of micropore volume and increase in external surface area for delaminated materials relative to their calcined 3D zeolite counterpart, whereas FTIR and multinuclear NMR spectroscopies demonstrate synthesis of Bronsted acid sites upon delamination. Comparative synthetic studies demonstrate that this new delamination method requires (i) a borosilicate layered zeolite precursor, in which boron atoms can be isomorphously substituted by aluminum, (ii) neutral amine pore fillers instead of rigid and large quaternary amine SDAs, and (iii) careful temperature control, with the preferred temperature window being around 135 C for ERB-1P delamination. Acylation of 2-methoxynaphthalene was used as a model reaction to investigate the catalytic benefits of delamination. A partially dealuminated delaminated material displays a 2.3-fold enhancement in its initial rate of catalysis relative to the 3D calcined material, which is nearly equal to its 2.5-fold measured increase in external surface area. This simple, surfactant- and sonication-free, mild delamination method is expected to find broad implementation for the synthesis of delaminated zeolite catalysts.
Catalytic applications of OSDA-free Beta zeolite
De Baerdemaeker, Trees,Yilmaz, Bilge,Mueller, Ulrich,Feyen, Mathias,Xiao, Feng-Shou,Zhang, Weiping,Tatsumi, Takashi,Gies, Hermann,Bao, Xinhe,De Vos, Dirk
, p. 73 - 81 (2014/01/06)
Beta zeolite obtained from seeded synthesis without the use of organic structure directing agents (OSDAs) has been used as a catalyst in different types of reactions. The large number of strong acid sites resulted in a high activity for the alkylation of benzene with ethene and a high cracking activity in the hydroconversion of n-decane. However, the high framework polarity resulted in fast deactivation in the acylation of aromatic ethers. Dealumination treatments resulted in improved stability in alkylation reactions with the more reactive olefins like propene. In acylation reactions, the activity was significantly increased, and in hydroconversion, a better balance between the hydrogenation/dehydrogenation and the acid sites was obtained.
Preparation and characterization of Zr-MCM-41 synthesized under microwave irradiation condition for acetylation of 1,2-dimethoxybenzene with acetic anhydride
Bachari,Chebout,Guerroudj,Lamouchi
experimental part, p. 367 - 381 (2012/06/01)
The liquid phase of acetylation of 1,2-dimethoxybenzene with acetic anhydride has been investigated over a series of acid zirconium mesoporous materials (Zr-MCM-41) synthesized by a microwave irradiation method with different Si/Zr ratios (Si/Zr = 90, 60, 10) and characterized by several spectroscopic techniques such as: N2 physical adsorption, ICP, XRD, TEM, FT-IR, UV-vis and a temperature-programmed desorption (TPD) of pyridine. In fact, the catalyst Zr-MCM-41 (10) showed a greater performance in the acid-catalyzed acetylation of 1,2-dimethoxybenzene employing acetic anhydride as an acylating agent. Furthermore, the kinetics of the acetylation of 1,2-dimethoxybenzene over these catalysts have also been investigated. Springer Science+Business Media B.V. 2011.
