Methylation of cyclodextrins by phase-transfer catalysis

P. Bakó, László Fenichel, L. Tőke, Lajos Szente, József Szejtli

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

A new, simple method has been developed for the methylation of cyclodextrins. The reaction proceeds in the heterogeneous phase with dimethyl sulphate, using a solvent in which the original cyclodextrins and the bases used are poorly soluble or insoluble. However, in the presence of phase transfer catalysts, methylation proceeds with good yields. The products are mixtures of randomly methylated cyclodextrins (RAMEB), containing 60-70% of heptakis(2,6-di-O-methyl)-β-cyclodextrin (DIMEB), 10-15% of heptakis(2,3,6-tri-O-methyl)-β-cyclodextrin (TRIMEB) and some monomethylated isomers. These methylated products have proved to be excellent detergents; e.g., they are able to significantly increase the water solubility of hydrocortisone, methyltesterone, etc. On repeating methylation twice, the amount of TRIMEB increases, and a pure product (28% yield) can be obtained by crystallisation.

Original languageEnglish
Pages (from-to)307-314
Number of pages8
JournalJournal of Inclusion Phenomena and Molecular Recognition in Chemistry
Volume18
Issue number3
DOIs
Publication statusPublished - Sep 1994

Fingerprint

methylation
Methylation
cyclodextrins
Cyclodextrins
Catalysis
catalytic activity
catalysis
products
detergents
dimethyl sulfate
sulfates
isomers
solubility
crystallization
water solubility
catalysts
Crystallization
Isomers
Detergents
Solubility

Keywords

  • Methylated cyclodextrins
  • phase-transfer catalysis

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Chemistry(all)

Cite this

Methylation of cyclodextrins by phase-transfer catalysis. / Bakó, P.; Fenichel, László; Tőke, L.; Szente, Lajos; Szejtli, József.

In: Journal of Inclusion Phenomena and Molecular Recognition in Chemistry, Vol. 18, No. 3, 09.1994, p. 307-314.

Research output: Contribution to journalArticle

Bakó, P. ; Fenichel, László ; Tőke, L. ; Szente, Lajos ; Szejtli, József. / Methylation of cyclodextrins by phase-transfer catalysis. In: Journal of Inclusion Phenomena and Molecular Recognition in Chemistry. 1994 ; Vol. 18, No. 3. pp. 307-314.
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