IN THE TITLE COMPOUND [SYSTEMATIC NAME: 5-(5,7-dihydr-oxy-4-oxo-4H-chromen-yl)-2-hydroxy-benzene-sulfonic acid dihydrate], C(15)H(10)O(8)S·2H(2)O, the benzopyran-one ring is not coplanar with the phenyl ring, the dihedral angle between them being 41.35 (3)°. No H atom was placed on the sulphonic acid group because it was not possible to distinguish between the two S=O bonds and the S-O bond. In...

Heparin-based anticoagulants are drugs of choice in the therapy and prophylaxis of thromboembolic diseases. Idraparinux is a synthetic anticoagulant pentasaccharide based on the heparin antithrombin-binding domain. In the frame of our ongoing research aimed at the synthesis of sulfonic acid-containing heparinoid anticoagulants, we elaborated a modular pathway to obtain a series of idraparinux-a...

Catalytic activities of eight sulfonic acid group functionalized ionic liquids in water were compared for the hydrolysis of Sigmacell cellulose (DP ~ 450) in the 150-180°C temperature range by measuring total reducing sugar (TRS) and glucose produced. The catalytic activity of acidic ionic liquids with different cation types decreases in the order imidazolium > pyridinium > triethanol ammonium ...

The preparation of 5-bromo-2-naphthol (4) in three steps from 5-amino-2-naphthol (1) is described. A sulfonic acid group is introduced at the 1-position as an activating and protecting group for the Sandmeyer reaction. The sulfonate group allows for the use of only water and sulfuric acid as solvents. The sulfonic acid is introduced with three equivalents of sulfuric acid, and it is removed in ...

Catalytic materials bearing multiple sulfonic acid functional groups and positioned at varying distances from one another on the surface of mesoporous solids are prepared to explore the effects that the spatial arrangement of active sites have on catalytic activity and selectivity. A series of organosiloxane precursors containing either disulfide or sulfonate ester functionalities (synthons of ...

Homogenous bis-sulfonic acid ionic liquids (1 mol equiv.) in DMSO (10 mol equiv.) at 100 °C efficiently mediated the conversion of D-fructose into 5-hydroxymethyl-2-furfural in 75% isolated yield, which was roughly a 10% increment compared to the case of the mono-sulfonic acid ionic liquids.