Nitration Nitrosation

The observation of nitration nitrosation for mesitylene is important, for it shows that this reaction depends on the reactivity of the aromatic nucleus rather than on any special properties of phenols or anilines. 

Many reactions, nitration, nitrosation, oxidation, etc are then possible. Titov s generalized scheme is... 

Radiation-induced substitution reactions have been reviewed by Wilson (1972) with examples of nitration, nitrosation, sulfochlorination, and others. These generally proceed by a free-radical mechanism. The free radicals are generated by the action of radiation on the reagent, which is present in large excess—for example,... 

Neighbouring group participation by carbonyl groups in ester hydrolysis, 28, 171 Nitration, nitrosation, and halogenation, diffusion control and pre-association in, 16, 1 Nitrosation, mechanisms, 19, 381... 

Several electrophilic substitutions were reviewed in CHEC-II(1996) <1996CHEC-II(8)421> and some similar transformations have been reported more recently. These include nitrations, nitrosations, azo couplings, and Friedel-Crafts-related transformations. 

Treatment of bis(dimethylaminomethylene)pyrrolizinium perchlorate (29) with cyclopentadiene-NaH in DMF gave the diatropic cyclopenta-[fc]cycl[4,2,2]azine (77), which was also obtained from the fulvene derivative (78) and 3//-pyrrolizine (25). Electrophilic substitutions (deuteration, nitration, nitrosation, acylation, bromination, Mannich reaction) occur in the 6- and 8-positions.32... 

Substrate Concentration (mmoll 1) Oxidation Nitration Nitrosation Ref. 

Nitration, nitrosation, and halogenation, diffusion control and pre-association in, 16, 1... 

In contrast to aliphatic alcohols, which are mostly less acidic than phenol, phenol forms salts with aqueous alkali hydroxide solutions. At room temperature, phenol can be liberated from the salts even with carbon dioxide. At temperatures near the boiling point of phenol, it can displace carboxylic acids, e.g. acetic acid, from their salts, and then phenolates are formed. The contribution of ortho- and -quinonoid resonance structures allows electrophilic substitution reactions such as chlorination, sulphonation, nitration, nitrosation and mercuration. The introduction of two or three nitro groups into the benzene ring can only be achieved indirectly because of the sensitivity of phenol towards oxidation. Nitrosation in the para position can be carried out even at ice bath temperature. Phenol readily reacts with carbonyl compounds in the presence of acid or basic catalysts. Formaldehyde reacts with phenol to yield hydroxybenzyl alcohols, and synthetic resins on further reaction. Reaction of acetone with phenol yields bisphenol A [2,2-bis(4-hydroxyphenyl)propane]. 

---