90281-25-7Relevant academic research and scientific papers
Aromatic Sulphonation. Part 93. Sulphonation of the Three t-Butylphenols, Four Di-t-butylphenols, and 2,4,6-Tri-t-butylphenol
Lambrechts, Hans J. A.,Mul, John,Cerfontain, Hans
, p. 677 - 682 (1985)
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.
