The reusable couple “PTSA/1-alkyl-3-methylimidazolium ionic liquids”: excellent reagents–catalysts for halogenation of fatty diols

• Published in: Journal of molecular catalysis. A, Chemical Chemical, 2004-08, Vol.218 (1), p.41-45
• Main Authors: Nguyen, Hoang-Phuong, Kirilov, Plamen, Matondo, Hubert, Baboulène, Michel
• Format: Article
• Language: English
• Subjects: Brønsted acid catalysis; Catalysis; Catalytic reactions; Chemistry; Dihalogenation; Exact sciences and technology; Fatty alcohols; General and physical chemistry; Ionic liquids; Microwaves; PTSA; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry
• ISSN: 1381-1169; 1873-314X
• DOI: 10.1016/j.molcata.2004.04.004

The conversion of 1, ω-dialcohols (C 6–C 16) to dihalides—dibromides and diiodides—was successfully obtained in the couple “PTSA/1-alkyl-3-methylimidazolium ionic liquids” (OMIM/X, BMIM/X; i-PMIM/X) for 2 h at 110 °C. The dihalogenation was improved by use of microwave irradiation. The couple “PTSA-ionic liquid” was regenerated and reused. The conversion of 1,ω-dialcohols (C 6–C 16) to dihalides—dibromides and diiodides—was successfully obtained in the couple “PTSA/1-alkyl-3-methylimidazolium ionic liquids” (OMIM/X, BMIM/X; i-PMIM/X) for 2 h at 110 °C. The dihalogenation was improved by the use of microwaves irradiation. The “PTSA-ionic liquid”-couple was regenerated and reused. The kinetics of halogenation of fatty dialcohols confirmed the A2 (or SN2c) mechanism in which monohalogenation was four-fold faster than dihalogenation.