567-18-0Relevant articles and documents
Process for preparing a synthetic aluminium tanning agent
-
, (2008/06/13)
A novel synthetic aluminium tanning agent as an alternative for chromium based tanning salts without using formaldehyde was prepared by using aromatic polymeric matrix and aluminium (III) salts as raw materials with suitable masking agents. The preparation of the syntan consists of sulphonation of aromatic molecule, which is incorporated with a polymeric network along with ligands specially designed for the complexation of aluminium (III) salts. The complex can be used as a self-tanning agent in leather industry with fairly good filling behavior. The tanned leathers exhibit shrinkage temperature about 85° C. Due to the higher precipitation point of the product, it can be used for tanning directly after deliming thus eliminating the pickling process. This product, unlike the conventional phenol based products, does not undergo photo-oxidation thereby preventing the discoloration of the tanned leathers.
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.
