Naphthalenes methoxy

Methoxynaphthalenes. C10H7-O.CH3, mw 158.21. There are two isomers 1-methoxy- 2-methoxy naphthalene... 

Methoxy-Naphthalene (Me thy 1-0-naphthyl-ether). Cryst, mp 13—14°, bp 274°. Sol in eth, chlf benz. Prepn from K-0-napthalate by heating with methyl chloride at 300°... 

CO 2 —220.52%, cryst from petr ether plus benz or from ale, mp 120—23° (decompn). Sol in ale petr eth plus benz. Prepn from an AcOH soln of 2-methoxy-naphthalene reacted with a HC1 satd suspension of paraformal dehyde in AcOH Ref Beil 6, 3020 ... 

M = Solvent Pyrene Paraffin oil 1-Methyl-naphthalene Ethanol 2-Methyl- naphthalene Ethanol 1,6-Dimethyl-naphthalene Ethanol 1-Methoxy- naphthalene Toluene 2-Methoxy- naphthalene Toluene... 

Olivo, D. Parker, Oxidation of 2-methoxy-naphthalene by toluene, naphthalene and biphenyl dioxygenases structure and absolute stereochemistry of metabolites, Bioorg. Med. Chem. 1994, 2, 727-734. 

Yadav, G. D., Krishnan, M. S. Solid acid catalysed acylation of 2-methoxy-naphthalene role of intraparticle diffusional resistance, Chem. Eng. Sci., 1999, 54, 4189-4197. 

In the reaction of 1-naphthoxide ions, a mixture of 2- and 4-aryl-, along with 2,4-diaryl-l-naphthol, is formed. However, substitution occurs only at C4 with the 2-Me-substituted anion (50-70% yields) [1[. On the other hand, 2-naphthoxide ions react with ArX to give substitution only at Cj of the naphthalene ring [32, 33]. The reactivity of the 2-naphthoxide ions allows the synthesis of naphthylpyridines, naphthylquinolines, and naphthylisoquinolines via their coupling reactions with the corresponding halo arenes, in good to excellent yields (50-95%) [33], The photostimulated reaction between 2-naphthoxide ions and l-iodo-2-methoxy-naphthalene was explored in liquid ammonia, as a novel approach to the synthesis of [1,1 ] binaphthalenyl-2,2 -diol (BINOL) derivatives (Scheme 10.23). This procedure has also been applied to the synthesis of BINOL in moderate yield (40%), which represents the first report of an SRN1 reaction in water [34]. 

The simple ether derivatives, 2-methoxy-naphthalene [CAS no. 93-04-9], nerolin, and 2-ethoxy-naphthalene [CAS no. 93-18-5] now are made easily by methylation (using dimethyl sulfate) or ethylation (using di-ethylsulfate) for use in perfume formulation and more recently as drugs intermediates. 

Lithiation of 1-methoxy naphthalene and 2-methoxy naphthalene needs some comments. In both cases lithiation occurs at two alternate positions which are ortho or sterically close to the lithiation directing group (—OCHj)... 

In 2-methoxy naphthalene lithiation occurs, to larger extent, at 3-position than at 1-position This is unexpected. Both the positions are ortho to the OCHj group. The acidity of 1-H is expected to be more because ofthe presence of 1,2-doubIe bond in naphthalene (this structure is more important than the one with 2,3-double bond). 

SOLID ACID CATALYSED ACYLATION OF 2-METHOXY-NAPHTHALENE ROLE OF INTRAPARTICLE DIFFUSION LIMITATION... 

The acylation of 2-substituted naphthalenes usually occurs at l-(a-) position [2]. But there are some exceptions where it can give rise to different kind of isomers by changing the reaction conditions [9]. 2-Methoxy naphthalene (2-MON) has been shown to be acetylated mostly either in l-(a)-position to yield l-acetyl-2-methoxynaphthalene or at 6-(P)-position to yield 2-acetyl-6-methoxynaphthalene depending on the catalyst and solvent systems used [10]. The a-isomer is rep)orted in most of the cases. But in the case of AICI3 catedysed acylation of 2-MON in presence of certain solvents, especially nitro compounds, a solvated nitro complex is formed by which acylation at the P-position is preferred [3]. 

The effect of solvent was tested by conducting the reaction in presence of nitrobenzene (Ph-N02), dichloroethane (DCE) and carbon disulphide (CS2). The volume of the solvents was kept constant (25ml). 2-MON and acetic anhydride were taken under otherwise similar conditions. DCE and PI1NO2 offer practically the same conversions (Fig.8). The selectivity also remains the same towards the ortho product (l-acetyl-2-methoxy naphthalene). In the absence of solvents, the conversions were much lower. 

Mordenite etc. Dodecatungstophosphoric acid (DTPA) and the ion exchange resin catalysts showed maximum activities. Clay based catalysts and sulphated zirconia showed a moderate activity. Zeolites did not demonstrate any activity to the reaction due to pore size restriction. A 100% selectivity towards the ortho product (l-acetyl-2-methoxy naphthalene) was observed for almost all the reactions for all the catalysts. The para product (2-methoxy-6-acetyl naphthalene) was formed when the aluminium chloride was used as a homogeneous catalyst with nitrobenzene as the solvent. The reaction product was isolated and conformed by the melting point, FT-IR, H-NMR, etc. The reaction is intraparticle diffusion limited. A different catalyst would be required to get p-product selectively. 

Moreau, R, Finiels, A., Meric, R, and Fajula, F. 2003. Acetylation of 2-methoxy-naphthalene in the presence of Beta zeolites influence of reaction conditions and textural properties of the catalysts. Catal. Lett. 85 199-203. 

Harvey, G. and Mader, G. 1992. The shape-selective acylation of 2-methoxy-naphthalene, catalyzed by zeolites Y, Beta and ZSM-12. Collect. Czech. Chem. Commun. 57 862-868. 

Gunnewegh, E.A., Gopie, S. S., and van Bekkum, H. 1996. MCM-41 type molecular sieves as catalysts for the Friedel-Crafts acylation of 2-methoxy-naphthalene. /. Mol. Catal. A Chem. 106 151-158. 

Cyclododecylidene pyri-dine-2-carboxamidrazone Acrylamidopyridine, 5-anthracen-9-ylmethylene 3- acrylamidorhodanine, 5-(2-methoxy-naphthalen-l-ylmethylene)-3-acrylamidorhodanine or 7-hydroxy- 4- methylcoumarin acrylate TRIM or EDM A New functional monomer fluorescence sensor [130]... 

The photo-addition of diphenylacetylene to 1,4-dimethoxynaphthalene has been described, and transformations of the product (396) discussed. " A companion paper ° deals with the chemical reactions of the trans-photodimer of 2-methoxy-naphthalene. 

Scheme 15.9 is once again similar to Scheme 15.6 except that the protonation back reaction is bimolecular. Thus, the two-state formalism is applicable with some changes concerning the determination of the fourth unknown. Because the lifetime of N in the absence of reaction, tn = 1 / fn> cannot be reliably measured with N even at very low pH values, it has to be obtained with a parent compound, with which the proton transfer reaction does not occur (in this case, 2-methoxy-naphthalene). However, the implicit assumption of the procedure, that the lifetime measured with the methoxylated compound would be equal to tn, may be dangerous with the strongly hydrogen bonding solvent water (the most common solvent for proton transfer). 

---