87231-06-9Relevant academic research and scientific papers
On the positional reactivity order in the sulfuric acid sulfonation of the two naphthalenesulfonic acids
Wit, Peter De,Cerfontain, Hans
, p. 1453 - 1455 (2007/10/02)
The sulfonation in 98.5percent H2SO4 at 25.0 deg C of naphthalene-1-sulfonic acid yields 58percent 1,5-, 32percent 1,6-, and 10percent 1,7-disulfonic acids and that of the 2-sulfonic acid 4percent 1,3-, 74percent 1,6-, 18percent 1,7-, and 4percent 2,6- + 2,7-disulfonic acids.Further sulfonation of the latter disulfonic acid mixture in 105.2percent H2SO4 at 25.0 deg C yields 78percent 1,3,6- and 12percent 1,3,5- + 1,3,7-trisulfonic acids.Reaction of naphthalene-1,5-disulfonic acid with 105.2percent H2SO4 at 25 deg C yields 5-sulfonaphthalene-1-sulfonic anhydride.Partial rate factors for the sulfonation of naphthalene-1- and -2-sulfonate in highly concentrated aqueous sulfuric acid (where the sulfonating entity is H2S2O7) are reported.They are discussed in terms of the difference in the reactivity of the α- and β-positions of the naphthalene skeleton and the electronic and steric effects of the sulfonate substituent already present.
