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Aniline and its ring-substituted derivatives react with nitrous acid to form diazonium salts. One example is benzenediazonium tetrafluoroborate. Through these intermediates, the amine group can be converted to a hydroxyl (−OH), cyanide (−CN), or halide group (−X, where X is a halogen) via Sandmeyer reactions.
In chemistry, a hydroxy or hydroxyl group is a functional group with the chemical formula −OH and composed of one oxygen atom covalently bonded to one hydrogen atom. In organic chemistry , alcohols and carboxylic acids contain one or more hydroxy groups.
Protecting groups cleaved by heavy metal salts or their complexes. Photolabile protecting groups; Double-layered protecting groups; Various groups are cleaved in acid or base conditions, but the others are more unusual. Fluoride ions form very strong bonds to silicon; thus silicon protecting groups are almost invariably removed by fluoride ions.
An electron donating group (EDG) or electron releasing group (ERG, Z in structural formulas) is an atom or functional group that donates some of its electron density into a conjugated π system via resonance (mesomerism) or inductive effects (or induction)—called +M or +I effects, respectively—thus making the π system more nucleophilic.
The resulting intermediate, named the Meisenheimer complex (2a), the ipso carbon is temporarily bonded to the hydroxyl group. This Meisenheimer complex is extra stabilized by the additional electron-withdrawing nitro group (2b). In order to return to a lower energy state, either the hydroxyl group leaves, or the chloride leaves.
Key to the alkylation of alcohols is the use of catalysts that render the hydroxyl group a good leaving group. The largest scale N -alkylation is the production of the methylamines from ammonia and methanol , resulting in approximately 500,000 tons/y of methylamine , dimethylamine , and trimethylamine .
Aniline absorbs in the K (220 - 250 nm) and the B (250 - 290 nm) bands exhibited by benzenoid compounds. The K and B bands arise from π to π* transitions as a result of the a group containing multiple bond being attached to the benzene ring. When dissolved in ethanol, λ max for aniline is 230 nm, but in dilute aqueous acid λ max is 203 nm ...
The acidity of the hydroxyl group in phenols is commonly intermediate between that of aliphatic alcohols and carboxylic acids (their pK a is usually between 10 and 12). Deprotonation of a phenol forms a corresponding negative phenolate ion or phenoxide ion , and the corresponding salts are called phenolates or phenoxides ( aryloxides according ...