Tetrahydrothiophenes

With an acidic catalyst, butanediol and hydrogen sulfide give tetrahydrothiophene [110-01-0] C HgS (138). 

Properties. Sulfolane [126-33-0] C4HgS02 (1), also known as tetrahydrothiophene-1,1-dioxide and tetramethylene sulfone, is a colorless, highly polar, water-soluble compound. Physical properties are given ia Table 1 (1). 

Reduction and Hydrodesulfurization. Reduction of thiophene to 2,3- and 2,5-dihydrothiophene and ultimately tetrahydrothiophene can be achieved by treatment with sodium metal—alcohol or ammonia. Hydrogen with Pd, Co, Mo, and Rh catalysts also reduces thiophene to tetrahydrothiophene [110-01-0] a malodorous material used as a gas odorant. 

Tetrahydrothiophene [110-01-0] M 88.2, m -96 , b 14.5 /10mm, 120.9 /760mm, d 0.997, n 1.5289. Crude material was purified by crystn of the mercuric chloride complex to a constant melting point. It was then regenerated, washed, dried, and fractionally distd. [Whitehead et al. 7 Am Chem Soc 73 3632 7957.] It has been dried over Na2S04 and distd in a vacuum [Roberts and Friend J Am Chem Soc 108 7204 1986]. 

Tetramethylene sulfoxide (tetrahydrothiophen 1-oxide) [1600-44-8] M 104.2, b 235-237°, d 1.175, n 1.525. Shaken with BaO for 4 days, then distd from CaH2 under reduced pressure. 

The Sulfinol process from Shell Development Company is a good example of the physical/chemical type of process. It blends a physical solvent and an amine to obtain the advantages of both. The physical solvent is Sulfolane (tetrahydrothiophene dioxide) and the amine is usually DIPA (diisopropanol amine). The flow scheme is the same as for an amine plant. ... 

Chemical Designations - Synonyms Sulfolane-W Tetrahydrothiophene-1,1-dioxide Tetramethylene sulfbne Chemical Formula CHjCHjCHjCHjSOj. 

Licensed by Shell the Sulfinol process combines the properties of a physical and a chemical solvent. The Sulfinol solution consists of a mixture of sulfolane (tetrahydrothiophene 1-1 dioxide), which is a physical solvent, diisopropanolamine (DIPA), and water. DIPA is a chemical solvent that was discussed under the amines. 

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