Benzenes methoxylated

In isolating higher-melting compounds prepared by this method (e.g., 7-naphthylbutyric acids), the layers are separated after cooling to 50-60°, benzene is used for the extraction, and the combined solution is clarified with Norite while still wet, concentrated somewhat, and allowed to cool for crystallization. In preparing methoxylated adds such as 7-anisyl- or 7-veratryl-butyric acid some demethylation occurs and a modification is necessary. The toluene layer and extracts are mixed with an excess of dilute sodium hydroxide and the organic solvents are... 

EtOH), is insoluble in benzene or ether, and sparingly in chloroform, but dissolves readily in alkali, the solution darkening in air. The salts are crystalline but unstable. The base forms a crystalline metbiodide and contains two methoxyl and two phenolic hydroxyl groups. On methyla-tion it yields a mixture of corydine and fsocorydine. On exhaustive methylation corytuberine yields eventually trimethylamine and 3 4 5 6-tetramethoxy-8-vinylphenanthrene, m.p. 69°. 

The von Braun reaction (Scheme 6) is another basic reaction for C—N bond cleavage 32). Tetrahydroberberine (26) was heated under reflux with cyanogen bromide in benzene to afford the bromocyanide (28) and the unsaturated cyanide (29) through C-6—N and C-14—N bond cleavage, respectively. The C-8—N bond cleavage product was not obtained because of the steric hindrance of the methoxyl group at C-9 in SN2-type reactions 33). The... 

The number of methoxyl groups per average benzene ring ... 

Various 3-methylcoumarilic acids substituted in the benzene ring by alkyl or methoxyl groups have been thus prepared, then decarboxylated to the corresponding benzofurans,10 208 e.g., 3-methyl-4,7-dimethoxy-benzofuran 2-naphthol233 leads to 3-methylnaphtho[2,l-6]furan (79), guaiacol to ethyl 7-methoxy-3-methyl coumarilate.234... 

Our constitutional scheme is based on different kinds of information. The first type of information comes from an analytical study of milled spruce wood lignin prepared according to Bjorkman (3). The analytical data considered comprise the elemental composition of lignin, its content of methoxyl groups and other ether bonds, the types and amount of its different hydroxyl groups, carbonyl, and lactone groups, and the kind and number of its biphenylyl linkages and other bonds in which the benzene nucleus is involved. The work that led to data of this kind has been carried out in various laboratories and has been described previously (9,11). 

To all rules, there are always exceptions. These have been made to allow unexpected natural isoquinolines that just happen to present unexpected substituents that nature for some reason chose to contribute to this collection. Mention has been made of an occasional carbonyl group disrupting the aromaticity of the benzene ring (this is the basis of the quinonic isoquinolines). The nitrogen atom (position 2) occasionally displays an amide group (these have been entered at the fourth letter of the structural alphabet). Several natural compounds demand a hydroxyl or methoxyl function at the isoquinoline 3- or 4-positions. When this occurs, the compound is listed as a footnote under the parent structure. 

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