Benzene 1,3,5-trimethoxy

Further substrate and solvent isotope effects were measured by Batts and Gold472 for the dedeuteration and detritiation of labelled 1,3,5-trimethoxy-benzene in aqueous protium- and deuterium-containing perchloric acid. Contrary to the observations above, they found the rate coefficients for dedeuteration to detritiation to be independent of the concentration of the catalysing acid (Table 125). Detritiation in the deuterium-containing aqueous perchloric acid media occurred 1.68 times faster than in the protium-containing media. 

The application of CFD methods also makes it possible to carry out the analysis of such inorganic substances as anions and metals. As an example let us consider the analysis of trace amounts of nitrates in water. Tan [44] proposed a simple and sensitive method for determining nitrates in aqueous solutions using GC—mass spectrometry (MS) with an ionic detector-multiplier. The method is based on the nitration of 1,3,5-trimethoxy-benzene (TMB) in sulphuric acid. In this medium the nitration follows the hydrolysis of the ether groups of TMB, and nitrobenzene is formed as the final product [44]. The reaction mixture is analysed by GC and detected with a mass spectrometer. Hexamethyl-benzene (HMB) is used as an internal standard. To avoid interference from nitrates and chlorides, sulphamic acid and mercury(ll) sulphate are used. 

Obtained by condensation of 2,3-dime-thoxybenzoic acid and 1,3,5-trimethoxy-benzene in the presence of aluminium chloride, zinc chloride and phosphorous oxychloride, prior to cyclisation into l-hydroxy-3,5-di-melhoxyxanlhone [1241]. 

Although there is considerable evidence that the principal basic site in mono alkoxybenzenes is the ether oxygen (15), a suitable accumulation of methoxy groups may make the aromatic ring the most attractive site for protonation through resonance stabilization of the resulting carbonium ion. Ring protonation of 1,3,5-trimethoxy-benzene is apparently an example (213). 

Elemioin is isomeric with asarone. It is 4-allyl-l. 2.6-trimethoxy-benzene, and is found in the essential oil of Manila elemi. Its characters are as follows —... 

Kresge et a/.498 have drawn attention to the fact that detritiation of [3H]-2,4,6-trihydroxy- and [3H]-2,4,6-trimethoxy-benzenes by concentrated aqueous perchloric acid gives correlations of log rate coefficient with — H0 with slopes of 0.80 and 1.14 respectively. Protonation to give the carbon conjugate acids is, however, governed by h0lA0 and h0l 9S, respectively, which suggests that the difference in kinetic acidity dependence is a property of the substrate and should not be interpreted as a major difference in mechanism. The kinetic difference can be eliminated by an appropriate comparison of kinetic and equilibrium acidity dependencies. In equation (230)... 

The three dimethoxybenzenes as well as the three trimethoxy-benzenes undergo smooth photocyanation, yielding in all cases the products to be expected from ortho-para orientation (Figure 9) (den Heyer, 1973). 

Anodic oxidation of 1,2,3-trimethoxybenzene in acetone containing dilute sulphuric acid gives 2,6-dimethoxybenzoquinone but in contrast 1,2,4-trimethoxy-benzene affords the dehydrodimer 11 in good yield [82]. Dehydrodimerization becomes an important process in the oxidation of methoxybenzenes in dichlo-... 

The 5-deutero and 4,6-dideutero derivatives of 1,2,3-trimethoxy-benzene were prepared by methylating the corresponding deuterated 2,6-dimethoxyphenols with dimethyl sulfate in 10% NaOH at room temperature. 

For phenol one can compare the effects of hydroxy and methoxy substituents. Scheme 19 shows effects of O-methyl substitution on pATas for protonation of a benzene ring containing one, two, and three hydroxy substituents. The pK s for di- and trihydroxy-substituted and methoxy-substituted benzenes were measured directly by Kresge et al.68 Again the stabilities of the hydroxy-substituted cations in water are consistently greater than methoxy. The importance of solvation in controlling these effects is demonstrated by the inversion of relative pK s of trihydroxy and trimethoxy benzene in concentrated solutions of perchloric acid.68 Thus the difference in p/fas is matched by a... 

It is well known that cyano derivatives of anthracene form charge transfer (CT) complexes with certain aromatic compounds. It was reported [67] that the radical cations formed upon irradiation of these complexes played an important role in initiation of cationic polymerization of cyclic ethers. Pyridinium salts were also found [68] to form CT complexes with hexamethyl benzene and trimethoxy benzene which result in the formation of a new absorption band at longer wavelengths where both donor and acceptor molecules have no absorption. This way the light sensitivity of the pyridinium salts may be extended towards the visible range. According to the results obtained from the... 

Therefore, the observed selectivity is the disguised chemical selectivity caused by an extremely fast reaction. The reaction using a microflow system, however, gives rise to a dramatic increase in the product selectivity. The monoalkylation product was obtained in excellent selectivity and the amount of dialkylation product was very small. In this case, a solution of the N-acyliminium ion and that of trimethoxy-benzene are introduced to a multilamination-type micromixer at —78°C and the product solution leaving the device was immediately quenched with triethylamine in order to avoid the consecutive reactions. Extremely fast 1 1 mixing using the micromixer and efficient heat transfer in the microflow system seem to be responsible for the dramatic increase in the product selectivity. 

However, the packing implications of this slight conformational difference are profound. Form I exhibits head-to-head and tail-to-tail packing toward the diagonal axis of the aZ)-plane. On Form II, a three fold screw axis passes by one of the />-fluorobenzenes, which stacks continuously, and the other/)-fluorobenzene lies along the axis. It was deduced that the difference in packing stability between the two polymorphs is caused mainly by the stability of the packing of the trimethoxy-benzene units. 

In contrast to the reactions with benzene, the reactions of 4 with 1-methoxybenzene, 1,2-dimethoxybenzene, and 1,2,3-trimethoxy-benzene result in the formation of the alkylation products 65 in... 

Anisole, and 1,2,3-Trimethoxy benzene Theoretical and Experimental Analysis of Aromatic Methoxy Solvation. 

Also obtained (by-product) by reaction of acetyl chloride on 1,2,4-trimethoxy-benzene with aluminium chloride in carbon disulfide at r.L [2410,3070,3072]. 

Preparation in two steps First, reaction of 3,4-di-methoxyphenyIacetyl chloride with 1,2,3-trimethoxy-benzene in the presence of aluminium chloride at 30-40° for 16 h. Then, the formed 2,3,4,3, 4 -penta-methoxydeoxybenzoin was demethylated by heating at reflux with pyridinium chloride [5463]. 

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