Sulfolane, 99%

General References:

1. High-boiling dipolar aprotic solvent. Compare Dimethyl sulfoxide, A13280, N,N-Dimethyl acetamide, A10924 and 1-Methyl-2-pyrrolidinone, A12260.
2. Solvent for nitrations using Nitronium tetrafluoroborate, B20167.
3. Widely used as solvent in the nucleophilic displacement of chloroaromatics with F^- (Halex fluorination). For example, chlorinated benzaldehydes were converted to their fluoro-analogues by heating with KF in tetramethylene sulfone at 220°: J. Fluorine Chem., 46, 529 (1990). Nitro groups have also been displaced by F^- by heating in the presence of tetramethylammonium chloride and phthaloyl chloride as a nitrite trap: J. Org. Chem., 56, 6406 (1991). See, however, Tetrahydrothiophene 1-oxide, A17502 and Potassium fluoride, 14130.
4. Use of this solvent makes possible the reduction of alkyl bromides to alkanes by NaBH₄: Tetrahedron Lett., 3495 (1969).
5. Can be doubly metallated at the ɑ-positions with strong bases such as NaNH₂, LiNH₂ or n-BuLi, and the resulting dianion reacted with one or two equivalents of benzophenone to give the mono- or bis-adduct respectively: J. Org. Chem., 35, 1834 (1970); J. Organomet. Chem., 59, 53 (1973). For alkylation of the monolithio-derivative, see: Synth. Commun., 18, 583 (1988).
6. Solvent for the Baylis-Hillman reaction, using 1,4-Diazabicyclo[2.2.2]octane, A14003, which enables short reaction times at room temperature: Tetrahedron Lett., 45, 1183 (2004).
7. Vergaelen, M.; Verbraeken, B.; Monnery, B. D.; Hoogenboom, R. Sulfolane as Common Rate Accelerating Solvent for the Cationic Ring-Opening Polymerization of 2-Oxazolines. ACS Macro Lett. 2015, 4 (8), 825-828.
8. Raghuram, N.; Suresh, R.; Ramesh, G.; Sowjanya, G.; Jyostna, T. S. Excess parameters for the binary mixtures of sulfolane with chloroethanes at different temperatures. J. Therm. Anal. Calorim. 2015, 119 (3), 2107-2117.