What is Sulphonation of naphthalene?
Aromatic sulfonation is a very important chemical transformation of organic compounds. 1,2 In the sulfonation of naphthalene, two isomers of α or β-sulfonic acid are formed, while the isolation of the indivisual compound is usually very difficult.
How is naphthalene synthesized?
Hint: There are five steps involved in the formation of naphthalene by Haworth synthesis. These are Friedel craft acylation, Clemmenson’s reaction, heating the compound, Clemmenson reaction, and dehydrogenation. Two aromatic rings joined are known as naphthalene.
What happens when naphthalene is heated with Sulphuric acid at different temperatures?
In industry naphthalene-monosulfonic acids are produced in a discontinuous process by reacting naphthalene batchwise with sulfuric acid, for the production of the α-acid at a temperature of up to about 50° C., for the preparation of the β-acid at a 160° to 165° C.
What happens when naphthalene is treated with sulfuric acid at 165 C?
Naphthalene reacts with concentrated sulfuric acid to yield naphthalenesulfonic acids.
What happens when naphthalene is treated with Sulphuric acid?
(1) Naphthalene reacts with concentrated sulfuric acid to form β-naphthalene sulfonic acid at high temperature. The reaction is intense and the temperature is not easy to control. The naphthenic acid ratio of 1:2 was used to synthesize the condensation product of β-naphthalene sulfonic acid formaldehyde condensate.
Is naphthalene pure or impure?
determination of a melting point, eg for naphthalene (pure substance) or candle wax (impure substance)
What happens when naphthalene treated with Sulphuric acid?
(1) Naphthalene reacts with concentrated sulfuric acid to form β-naphthalene sulfonic acid at high temperature. The reaction is intense and the temperature is not easy to control. There are side reactions. Polysulfonation and sulfones may be formed, which affect the purity of the product.
Is Sulphonation electrophilic substitution?
Nitration and sulfonation of benzene are two examples of electrophilic aromatic substitution. The nitronium ion (NO2+) and sulfur trioxide (SO3) are the electrophiles and individually react with benzene to give nitrobenzene and benzenesulfonic acid respectively.
Which is part of the sulfonation of naphthalene?
Aromatic Sulfonation. Part XVI: Sulfonation of naphthalene and its monosulfonic acids in concentrated aqueous sulfuric acid – Cerfontain – 1967 – Recueil des Travaux Chimiques des Pays-Bas – Wiley Online Library Aromatic Sulfonation. Part XVI †: Sulfonation of naphthalene and its monosulfonic acids in concentrated aqueous sulfuric acid
How to make 1, 5-naphthalene disulfonic acid with sodium hydroxide?
Upon heating with dilute aqueous acid, it reverts to naphthalene. Fusion with sodium hydroxide followed by acidification gives 1-naphthol. Further sulfonation gives 1,5-naphthalene-disulfonic acid. Reduction with triphenylphosphine gives 1-naphthalenethiol .
How is the isomer distribution of naphthalene determined?
The kinetically determined isomer distribution has been determined in the acid range of 75.5‐95.2 wt‐% H 2 SO 4. At 25°, the ratio of 1‐ to 2‐naphthalenesulfonic acid decreases from 5.9 to 4.1 on varying the acid concentration from 75 to 95 wt‐% H 2 SO 4.
Why does naphthalene have a higher reactivity than the 2 position?
The higher reactivity of the 1‐ as compared with the 2‐position of naphthalene is largely due to the difference in enthalpy of activation, for the difference in entropy of activation is very small. The partial rate factors for sulfonation at the 1‐ and 2‐ positions decrease with increasing acid concentration.