Veratroles

Papaverine, used to treat heart diseases as a vasodilator, is a dmg that was originally made from vanillin but has since been made from veratrole and (9f2v (9-l,2-dimethoxybenzene. Vanillin is also used as a pharmaceutical excipient. 

The trifluoroacetic acid and veratrole used were Eastman Kodak Company white label grade. 

Iodoveratrole has been prepared by iodination of veratrole in the presence of mercuric oxide and by methylation of 4-iodoguaiacol with methyl iodide in alcoholic sodium ethoxide solution. ... 

Recently, nitration of organolithiums and Gngnards v/iih has been developed for the preparation of certain kmds of nitro compounds fEqs. 2.14 and 2.15. The success of this process depends on the reaction conthdons (low remperanirei and the stnicnire of substrates. For example, 3-nitrothiophene can be obtained in 70% overall yield from 3-bromothiophene this is far superior to the older method. 3-Nitroveratrole cannot be prepared usefully by classical electrophilic nitradonof veratrole, but it can now be prepared by direct orr/io-lithiadon followed The mechanism is believed to proceed by dirutrogen rathcal, followed by the rathcal s combinadon. 

Phenol ethers show some, admittedly low, reactivity towards diazonium ions and also undissociated phenols (see Sec. 12.7). An instructive example of the reactivity of phenol ethers was reported by Ronaldson (1981). He found that 1,2-dimethoxy-benzene (veratrole) does not react with the 4-nitrobenzenediazonium ion, but the azo coupling product is formed when the more electrophilic 2,4-dinitrobenzenediazo-nium ion is used. 

Other topical bleaching agents include arbutin, licorice, unsaturated fatty acids, soy extracts, serine protease inhibitors, ellagic acid, and res-veratrol [49]. 

Alkyl esters often show low reactivity for lipase-catalyzed transesterifications with alcohols. Therefore, it is difficult to obtain high molecular weight polyesters by lipase-catalyzed polycondensation of dialkyl esters with glycols. The molecular weight greatly improved by polymerization under vacuum to remove the formed alcohols, leading to a shift of equilibrium toward the product polymer the polyester with molecular weight of 2 x 10" was obtained by the lipase MM-catalyzed polymerization of sebacic acid and 1,4-butanediol in diphenyl ether or veratrole under reduced pressure. ... 

Neilson AH, A-S Allard, P-A Hynning, M Remberger, L Landner (1983) Bacterial methylation of chlorinated phenols and guiaiacols formation of veratroles from gnaiacols and high molecular weight chlorinated lignin. Appl Environ Microbiol 45 774-7S3. 

Demethylation of pentachloroanisole in rainbow tront (Salmo gairdneri = Oncorhyn-chus mykiss) (Glickman et al. 1977), and of chlorinated veratroles by zebra fish (Neilson et al. 1989). 

Vacuum was applied to shift the equilibrium forward by removal of the activated alcohol formed [30, 31, 37, 38]. In the enzymatic polycondensation of bis(2,2,2-trifluoroethyl) sebacate and aliphatic diols, the polymer with Mw of more than 1 x 104 was obtained using lipases CC, MM, PPL, and Pseudomonas cepacia lipase (lipase PC) as catalyst and lipase MM showed the highest catalytic activity [37]. Solvent screening indicated that diphenyl ether and veratrole were suitable for the production of the high molecular weight polyesters under vacuum. In the PPL-catalyzed reaction of bis(2,2,2-trifluoroethyl) glutarate with 1,4-butanediol in veratrole or 1,3-dimethoxybenzene, periodical vacuum method improved the molecular weight (Mw 4 x 104) [38]. 

Cyclopropane 87, obtained from n-butyl vinyl ether, rearranges to dihydrofuran 88 only at elevated temperature, and also partly during work-up on silica gel113). The complete conversion of 87 into veratrole by the action of HCl/CH3OH gave rise to the analogous two-step synthesis of hydrourushiol monomethyl ether from l-diazo-3,3-dimethoxy-2-nonadecanone 89113). Ether cleavage of the product yields hydrourushiol, one of the vesicant components of, inter alia, poison ivy. 

Valeraldehyde, p28 Valeric acid, p38 Valeronitrile, p35 Valeryl chloride, p45 Vanillic acid, hi43 Vanillin, hl42 Vanillyl alcohol, hl45 Veratraldehyde, d492 Veratric acid, d496 Veratrole, d493 Veronal, d330... 

Fig. 23 Benzodithiolene crown ether and veratrole complexes of transition metal... 

Lithium derivatives of dialkylamines react with aryl methyl ethers in refluxing THF by substitution to afford TV-aryldialkylamines (equation 10). Similarly, lithium piperidide and veratrole give 7V-(2-methoxyphenyl)piperidine (15)40. 

Another RP-HPLC method was applied for the determination of gallic acid, trans-veratrol, quercetin and rutin in red wines. Samples of wines were filtered and injected into... 

In the field of fine chemical synthesis there is an urgent need to substitute the cleaner technologies for the old polluting ones. It is hoped that the large economic and environmental benefits brought by the recently developed catalysis processes—acetylation of anisole and of veratrole, Beckmann rearrangement, and so forth—will initiate great strides in this field. 

The required arylamine 921 was prepared in a straightforward manner starting from commercial 3-methylveratrole (789). Regioselective bromination of the veratrole 789 afforded the 4-bromo derivative 790 in 88% yield. Halogen-metal... 

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