Ultra-high pressure direct syntheses of bis(imidazolium-3-yl)alkane dichlorides

TETRAHEDRON

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Article

Harwood, Laurence M.¹  Pitt, Phillip¹  Scott, Janet L.²  Sousa, Dora¹ 

[1] Univ Reading, Dept Chem, Reading RG6 6AD, Berks, England

[2] Univ Bath, Ctr Sustainable Chem Technol, 1 South,1-05, Bath BA2 7AY, Avon, England

关键词: Ultra-high pressure;    Menshutkin reaction;    Imidazolium salts;    Ionic liquids;    Hyperbaric;   

DOI  :  10.1016/j.tet.2019.130639

来源: Elsevier

【 摘 要 】

The ultra-high pressure Menshutkin reaction of N-substituted imidazoles and alpha,omega-dichloroalkanes provides access to a wide variety of bis(imidazoliumyl)alkane dichlorides in an efficient, one-pot process. Although the substitution reactions of dichloromethane at ambient pressure can be exceedingly slow, at 1.9 GPa, syntheses are usually quantitative in under 24 h. Reactions involving congested imidazole starting materials, that otherwise terminate after formation of the mono-imidazolium salt, are driven to the bis-imidazolium salt at 1.9 GPa. The rates of reaction increase with alpha,omega-dichloroalkane chain length, decrease with increasing bulk and imidazole N-substituent length, and the reactions of the more hindered imidazoles are more sensitive to the pressure-rate enhancement. (C) 2019 Elsevier Ltd. All rights reserved.

【 授权许可】

Free