Anisole chloro

Chlorine sometimes replaces a nitro group ortho to a diazonium group. When 2,3-dinitro-4-m ethoxyaniline is diazotized in the presence of hydrochloric acid and then treated with ethyl alcohol, 2-nitro-3-chloro-anisole is obtained48 in unspedfied yield. 

Photonucleophilic substitution of fluoro- and chloro-anisoles has been the subject of three reports within the year. Cornelisse and co-workers have studied the photocyanation and photohydrolysis of 4-fluoro- and chloro-anisoles by laser spectroscopy and report that the initial step of the reaction involves formation of a triplet state transient complex composed of a ground state and an excited state aromatic molecule. Only in the presence of water does the complex yield radical ions and it is this process which determines the product quantum yield. The radical cation then reacts with the nucleophile to give a neutral radical which yields the substituted arene in a single step. Liu and Weiss report on anomalous effects during photonucleophilic aromatic substitution of 2- and 4-fluoroanisoles and also on the photo-... 

Curtis R.F., Dennis C., Gee D.G., Gee M.G., Griffiths N.M., Land D.G., Peel J.L. and Robinson D. (1974) Chloroanisoles as a cause of musty taint in chickens and their microbiological formation from chloro-anisoles in broiler house litter. J. Sci. Food. Agric., 25, 811-828. 

The chlorination of anisole by HOCl in aqueous solution produces both p- and o-chloro-anisole, in a ratio of 60 40 [63]. By contrast, in the presence of a-cyclodextrin (cyclo-hexaamylose) the para chlorination dominates, so that with 10 mM cyclodextrin the product is 96% p- and 4% o-chloroanisole. In water solution anisole binds into the cyclodextrin cavity. The simplest idea would be that this binding blocks chlorination at the ortho positions, which are inside the cavity, while the para position of the anisole is still exposed to solution. The true situation is more interesting. When the reaction shows 96% selectivity for para chlorination, the anisole is only 72% bound, so the bound anisole must be more reactive, not just more selective, than that in solution. The data indicate that ortho chlorination is indeed completely blocked for the anisole/cyclodextrin complex, but that the para position is 5.6 0.8 times more reactive in the complex than in solution. It was suggested that the chlorine was being delivered to the para position of bound anisole by a hydroxyl group of the cyclodextrin, which had been converted to a hypochlorite group (Scheme 6-10). Later work confirmed this idea. 

There is also a single case reported in which a phenyl methyl ether was prepared from the corresponding aryl chloride. Potassium methoxide, activated by dicyclo-hexyl-18-crown-6 displaces a chloride ion from 1,2-dichlorobenzene to give 2-chloro-anisole in fair yield. None of the 3-isomer is isolated, indicating that the reaction is a nucleophilic substitution rather than a benzyne reaction [22]. 

Obtained by Friedel-Crafts acyladon of o-chloro-anisole with o-toluoyl chloride in the presence of aluminium chloride in tetrachloroethane at 120-130° for 3 h (25%) [508],... 

Preparation by reaction of p-anisoyl chloride with p-chloro-anisole in the presence of aluminium chloride in methylene chloride at r.t. for 18 h under nitrogen (41%) [472]. 

Preparation by oxidation of 2,2 -methylenebis(4-chloro-anisole) with chromium trioxide in refluxing acetic acid, followed by demethylation of the 5,5 -dichloro-2,2 -di-methoxybenzophenone so obtained with aluminium chloride in chlorobenzene at 60° for 5.5 h [295], (92%) [1320]. 

Preparation by reaction of acetyl chloride on 2,5-di-chloro-anisole with aluminium chloride at 110° (36%) [I860]. 

First of all, there are the two products of O-coupling addition of methoxide ion to the diazonium ion, the (Z)- and (jE)-diazo methyl ethers. As discussed in Section 6.2, they are formed in reversible reactions with half-lives of the order of a fraction of a second (Z) to a minute (E). The two diazo ethers are, however, decomposed rapidly to the final dediazoniation products. We show in Scheme 8-47 the products obtained by Broxton and McLeish (1983 b) in the dediazoniation of 4-chloro-3-nitrobenzenedi-azonium ion (8.64) with methoxide ion in CH3OH. The products are 4-chloro-3-nitro-anisole (8.65, 49 9o), 2-chloro-nitrobenzene (8.66, 449o), and 2-nitroanisole (8.67). 

Satchell476 also measured the first-order rate coefficients for dedeuteration of [4-3H]-anisole by acetic acid or acetic acid-hydrochloric acid media containing zinc and stannic chlorides (Table 128). The rates here paralleled the indicator ratio of 4-nitrodiphenylamine and 4-chloro-2-nitroaniline, so that the implication is that a linear relationship exists between log k and the unknown H0 values. The results also show the rate-enhancing effect of these Friedel-Crafts catalysts, presumably through additional polarisation of the catalysing acid, for in the absence of them, exchange between acetic acid and anisole would be very slow. Other studies relating to the effect of these catalysts are reported below (p. 238). 

Iodination versus chlorination. Three distinct classes of halogenation reactions are observed with various substituted methoxybenzenes and IC1 when carried out under an identical set of conditions, i.e., exclusive iodination, exclusive chlorination, and mixed chlorination and iodination. For example, equimolar mixtures of anisole, 2,5-dimethyl-1,4-dimethoxybenzene and 1,4-dimethoxybenzene and iodine monochloride (kept in the dark) yield p-iodoanisole, chloro-2,5-dimethyl- 1,4-dimethoxybenzene, and a (4 6) mixture of chloro- and iododimethoxybenzene, respectively, in nearly quantitative yields,225 i.e.,... 

ChT.ORODTTSOPROPYLPHOSPHINE, 48, 47 a-Chloro ethers as intermediates in de-methylation of anisoles, 47, 24 Chloroform, condensation with benz-aldehyde, 48, 27... 

The fluorination of other activated aromatic compounds, such as anisole and phenol, undergo monofluorination mainly in the ortho and para positions, whereas the fluorination of deactivated aromatics, such as nitrobenzene, trifluoromethylbenzene and benzoic acid, give predominantly the corresponding meta fluoro-derivatives which is consistent with a typical electrophilic substitution process. Also, fluoro-, chloro- and bromo-benzenes are deactivated with respect to benzene itself but are fluorinated preferentially in the ortho and para positions [139]. At higher temperatures, polychlorobenzenes undergo substitution and addition of fluorine to give chlorofluorocyclohexanes [136]. 

The products of the electrochemical perfluorination of aromatic and heteroaromatic compounds are the corresponding perfluorinated cyclic and heterocyclic alkanes.28 and also per-fluorinated derivatives of the heteroaromatic compounds. Perfluorocyclohexane is the principal product from the electrochemical fluorination of benzene and fluorobenzene. Chloro derivatives of perfluorocyclohexane are produced from chlorobenzenes. Anisoles give fully saturated per-fluoro ethers, together with cleavage products. Extensive cleavage is observed in the fluorination of benzenethiols. Chloropyridines, fluorocarbons and sulfur hexafluoride or nitrogen trifluoride are characteristic byproducts from the above scries of reactions. 

Zinc(II) fluoride converts l-chloro-2-nitrobenzene into l-fluoro-2-nitrobenzene in 49% yield in anisole under reflux for 8 hours.51... 

Trinitro-3 cbloroaniline or Methyl-(3 -chloro-2,4,6-trinitro-phenyl-ether), C1.C6H(N02)3.0.CH3 col crysts(from ale), mp 86-88° can be prepd by nitrating 3-chloronitro-anisole with nitric-sulfuric acid or by other methods. Its expl props were not detd Refs l)Beil 6, 292 [283] 2)J.J.Blanksma, Rec 21, 323(1902) [Called Oxymethylchloro-trinitrobenzene(1.3.2.4.6.)] 3)H.H.Schlubach F. Mergenthaler, Ber 58, 2734(1925 ) CA 20, 1395(1926)... 

Trinitro-5 -chloro-3-hydroxy anisole or 3-Chloro-3-methoxy-picric Acid, nearly col micro-prisms(from w), mp 14 7° was prepd by adding lg of 5 -chloro-3-hydroxyanisole to well-stirred 10 ml of nitric acid(d 1.4 7) at RT during 15 mins, followed by slow heating to bp, cooling and pouring on ice. Itsexpl props were not detd... 

Chlorohydrins, preparation from a-chloro acids. 66, 161 2-Chloromethoxybenzene Anisole, o-chloro- Benzene, 1-chloro-2-methoxy- (766-51-8), 67, 222... 

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