Applications

• Aromatic Extraction
• Acidic Gas Treatment
• Extractive Distillation
• Fractionation
• Reaction Solvent
• Polymerisation Solvent
• Polymer Processing/Textiles
• Dyestuffs
• Printing Ink
• Agrochemical
• Pharmaceutical
• Electronics

Reaction Solvent Quaternisation of pyridine, 4-picoline and 4- isopropylpyridine. Preparation of isocyanates. Production of sulphur from hydrogen sulphide and sulphur dioxide. Preparation of aromatic sulphonic acids. Production of fluoroaromatics by the Halogen Exchange (Halex) Process.

Sulfolane has been found to be an excellent solvent for reactions, particularly those where anhydrous and polar solvents are required. Some examples of these reactions are listed below:
• Quantitative quaternisation of Pyridine, 4-picoline and 4-isopropylpyridine in Sulfolane with n-butyl bromide. Use of Sulfolane eliminates the side reactions which may be experienced when other reactions solvents are used.
• Olefin isomerisation, Friedel-Crafts alkylations, carbonium ion rearrangement and hydrogen transfer processes with hydrofluoboric acid (HBF4) in Sulfolane benzene solvent systems.
• Preparation of isocyanate from phosgene and amine salts.
• Transition metal/bromide or iodide ion catalysed reactions of carbon monoxide with methanol or formates. For example, acetic acid has been prepared from methanol and carbon monoxide and from methyl formate and carbon monoxide, while acetaldehyde has been produced from methanol, carbon monoxide and hydrogen, and carbonate esters from methanol, carbon monoxide and air.
• Conversion of (a-olefins to methyl ketones.
• Hydrogen sulphide can be converted to sulphur by reaction with sulphur dioxide in the presence of urea or thiourea dissolved in Sulfolane.
• p-Nitrohalobenzenes are prepared by the nitration of halobenzenes in mixtures containing sulphuric acid and Sulfolane.
• Aromatic amines may be sulphonated with sulphuric acid in the presence of Sulfolane, eg sulphanilic acid from aniline and aromatic sulphonic acids can be made by the sulphonation of aromatic compounds.
• Production of tertiary butanol by the hydration of isobutene in the presence of an ionexchanger and in Sulfolane.
• Direct hydration of olefins, eg propylene to propylene glycol, in Sulfolane in the presence of osmium halides and transition metal compounds.
• Conversion of chlorinated or brominated compounds to the corresponding, more valuable, fluorinated compounds by halogen exchange. At reaction temperatures up to 250°C, a sodium fluoride suspension in Sulfolane exchanges halogen readily with such halides as acid chlorides, alphachloroethers, phosphorus oxychloride and trichloride. Chlorobenzonitriles and chloronitrobenzenes in Sulfolane can also be converted to the corresponding fluoro compounds.
• Open-celled, nonshrinking polyurethane foams have been made using Sulfolane.
• Sulfolane has been reported as conferring benefits when manufacturing certain dyes, either when it is used as a solvent, or when the synthesis is carried out in its presence.

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