- THE DESULFONATION OF PHENOLSULFONIC ACIDS IN AQUEOUS SODIUM HYDROGEN SULFATE MIXTURES
-
Phenol and phenolsulfonic acids are rapidly sulfonated and desulfonated in aqueous sodium hydrogen sulfate, with or without added sulfuric acid.At temperatures above 130 deg C, desulfonation competes with sulfonation sufficiently to allow steam stripping of phenol from the reaction mixtures, even under conditions of low water content.Above 170 deg C removal of phenol is less efficient because the water content is very low and the predominant species in the reaction mixture is 2,4,6-phenoltrisulfonate.Key words: Phenol; phenolsulfonic acid sulfonation; desulfonation; sodium hydrogen sulfate; kinetics; HPLC.
- Jason, Mark E.
-
-
- Aromatic Sulphonation. Part 93. Sulphonation of the Three t-Butylphenols, Four Di-t-butylphenols, and 2,4,6-Tri-t-butylphenol
-
The (homogeneous) sulphonation of the three t-butyl-phenols, 2,4-, 2,5-, 2,6-, and 3,5-di-t-butylphenol, and 2,4,6-tri-t-butylphenol with a number of sulphonating reagents has been studied, and product compositions have been determined.The formation of the several initial and eventual sulphonation products is explained in terms of sulphodeprotonation, protiode-t-butylation, sulphode-t-butylation, and isomerization, the relative importance of which is discussed for the various substrates. 2- (1) and 4-t-butylphenol (3), 2,4- (4), and 2,6-di-t-butylphenol (6), and 2,4,6-tri-t-butylphenol (8) in 98.5percent H2SO4 at 35 deg C after 10 days of reaction all yield 50 +/- 2percent 4-t-butylphenol-2,6- (9) and 50 +/- 2percent phenol-2,4-disulphonic acid (10).With both (1) and (6) the initial step is a rapid 1,3-shift of the t-butyl group from the 2- to the 4-position.With (1) this is then followed by sulphodeprotonation at the 2- and 6- position and with (6) by protiode-t-butylation at the 6-position followed by sulphodeprotonation at the 2- and 6-position.The formation of (9) from the substrates (3), (4), and (8) and the formation of (10) from (1), (3), (4), (6), and (8) is explained by protiode-t-butylation and subsequent sulphodeprotonation.
- Lambrechts, Hans J. A.,Mul, John,Cerfontain, Hans
-
p. 677 - 682
(2007/10/02)
-