Substitutions Nitration

Returning to Table 12 2 notice that halogen substituents direct an incoming electrophile to the ortho and para positions but deactivate the ring toward substitution Nitration of chlorobenzene is a typical example of electrophilic aromatic substitution m a halobenzene... 

Imidazolidine, 4,5-dichloro-l,3-diacetyl-imidazo[4,5-6]pyrazine synthesis from, 5, 646 Imidazolidine, 1,3-dimethyl-conformation, 5, 355 Imidazolidine, diphenyl-dehydrogenation, 5, 427 Imidazolidine, 2-imino-1-substituted nitration, 5, 427... 

In Volume 13 reactions of aromatic compounds, excluding homolytic processes due to attack of atoms and radicals (treated in a later volume), are covered. The first chapter on electrophilic substitution (nitration, sulphonation, halogenation, hydrogen exchange, etc.) constitutes the bulk of the text, and in the other two chapters nucleophilic substitution and rearrangement reactions are considered. 

For a discussion on the preferred site of attack for many ring systems, see de la Mare, P.B.D. Ridd, J.H. Aromatic Substitution Nitration and Halogenation Academic Press NY, 1959, p. 169. 

A paper concerned with the synthesis of pyridazino[3,4-fe]indoles 18 included a study of various conversions of 4,5-dichloro-2-methylpyridazin-3-one 17 including nucleophilic substitutions, Suzuki reactions and electrophilic substitution (nitration), combined with reductive dehalogenation, and usefully summarised previous work <06T121>. 

Charge-transfer activation as the unifying theme in electrophilic aromatic substitution — nitration 237... 

McKillop and Ford synthesized a range of primary and secondary alkyl nitrates in excellent yields by treating alkyl bromides with mercury (I) nitrate in 1,2-dimethoxyethane at reflux (Equation 3.9). This method has been used to synthesize substituted nitrate esters from both a-bromocarboxylic acid and a-bromoketone substrates. Unlike metathesis with silver salts, which are widely known to promote SnI reactions, this method is not useful for the synthesis of nitrate esters from tertiary alkyl halides. 

P. De la Mare and J. H. Ridd, Aromatic Substitution Nitration and Halogenation, Butterworth, London (1959). 

Aromatic Substitution-Nitration and Halo-genation. Title of a book by P.B.D. DeLaMare J.H.Ridd, Academic Press, NY(l959)... 

Nitro-substituted pyrroles have usually been prepared by electrophilic substitution on preconstructed pyrrole rings. Like other electrophilic substitutions, nitration gives primarily... 

The normal reactions of benzo[6]thiophene 1,1-dioxides have been reviewed (70AHC(11)177). Electrophilic substitution (nitration, bromination) takes place at position 6. 3-Halo derivatives undergo normal nucleophilic displacement reactions, but 2-bromobenzo[6]thiophene dioxide gives the 3-ethoxy derivative in ethanolic NaOH. The reaction of 3-methoxy derivatives with secondary amines can give rise either to enamines... 

Like other electrophilic substitutions, nitration of a substituted benzene, where the substituent is electron withdrawing (N02, C02H, CN, and so on Table 22-6), generally produces the 1,3-isomer. To prepare the 1,4-isomer, less direct routes are necessary— the usual strategem being to use benzene derivatives with substituent groups that produce the desired orientation on... 

P. H. Gtoggins, Unit Processes in Organic Synthesis, McGraw-Hill, New York (1958), p 204 P. B. D. de la Mare and J. H. Ridd, "Aromatic Substitution, Nitration and Halogenation, Butterworths Scientific Publications, London (1959)... 

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