1857-16-5Relevant academic research and scientific papers
Sulfonation of 1- and 2-naphthol and their methanesulfonate esters with sulfur trioxide. The influence of initial sulfation on the sulfo-product composition
Ansink, Harold R. W.,Zelvelder, Erwin,Cerfontain, Hans
, p. 210 - 215 (1993)
The sulfonation of 1- and 2-naphthol with sulfur trioxide in C(2)H3NO2 has been studied by using 1H NMR. 1-Naphthol (1) yields, upon reaction with 1.0 mol-equiv of SO3, a mixture of 2- and 4-sulfonic acids (2- and 4-S); upon increasing the reaction temperature, the relative amount of 2-S increases.Upon reaction with 4.0 mol-equiv of SO3, the initially observed products are the hydrogen sulfate 1-O,2,4-S3 and some corresponding sulfonic anhydrides.After prolonged reaction times, some 1-O-4,7-S3 is formed. 2-Naphthol (3), upon reaction with 1.0 mol-equiv of SO3, yields a 85:15 mixture of 1-S and 8-S, whereas upon reaction with 2.0 mol-equiv of SO3, a 8:14:78 mixture of 5-S, 6-S and 8-S are formed.Sulfonation of 3, either by (i) reaction with 1.2 and, subsequently, an additional 2.0 mol-equiv of SO3, or (ii) by direct addition of 4.0 mol-equiv of SO3, yields a mixture of the carbyl sulfates 5-5-S and 5-6-S and the hydrogen sulfate 3-O,6,8-S3, the relative yield depending on the method used.The results are discussed in terms of initial formation of the corresponding naphthyl hydrogen sulfates and on the basis of a comparison with the reactions of 1- and 2-naphthyl methanesulfonates, the chosen model compounds for the hydrogen sulfates, with SO3.
Isomerization and Sulfodeprotonation in the Reaction of 1,6-Oxidoannulene, 1,6-Iminoannulene, Their Isomers 1-Naphthol and 1-Aminonaphthalene, and 11-Oxo-1,6-methanoannulene with SO3
Koeberg-Telder, Ankie,Cerfontain, Hans
, p. 2563 - 2567 (2007/10/02)
The reactions of 1-naphthol (3), 1-aminonaphthalene (10), and 1,6-oxido- (1), 1,6-imino- (2), and 11-oxo-1,6-methanoannulene (15) with SO3 in aprotic solvents have been studied.With 3 the initial product is 1-naphthyl hydrogen sulfate (4), which is slowly converted into the 1-naphthol-2- (5) and -4-sulfonic acid (6) via O-desulfonation and C-sulfonation on using is less than or equal to 1 equiv of SO3, but via C-sulfonation and O-desulfonation if the SO3 is in a large excess.It is suggested that on using is less than or equal to 1 equiv of SO3 the conversion of 4 into the 2-sulfonic acid 5 proceeds intramolecularly.The annulene 1 with SO3 in dioxane initially yields 1-naphthol and its hydrogen sulfate (4), which at temperatures >-30 deg C undergo ring sulfonation (vide supra).The nitrogen-containing substrates behave quite similarly to their oxygen analogues in that both 10 and 2 yield 10-2-SO3H, 10-4-SO3H, and 10-2,4-(SO3H)2.With 2, the initial product is the N-sulfonic acid 9.The ketone 15 undergoes ring substition with formation of the 2-sulfonic and 2,7-disulfonic acids.Mechanisms have been presented to rationalize the skeletal rearrangements of the annulenes 1 and 2.
