The invention relates to a method for preparing hepta-[2,6-di -O- methyl]-beta-cyclodextrin by methylating beta-cyclodextrin in an organic phase, wherein the beta-cyclodextrin is methylated with dimethyl sulfate in the presence of alkali metal hydroxide at a temperature of-65 DEG C to 0 DEG C.
Inventors: Szejtli, Jozsef (Budapest, Hu)
Liptak, (Debrecen, Hu)
Nanas, Parr (Debrecen, Hu)
Peter Fugdi (Debrecen, Hu)
Jodahl Ildico (Debrecen, Hu)
Candeira, Lily (Debrecen, Hu)
Janosi, (Debrecen, Hu)
ApplicationNo.: 06/586203, date of publication: 09/ 17/ 1985, date of application: 03/05/ 1984, view patent picture: download pdf 454221/pdf to help export references:
Elementary class: 536/ 103 International class: C08B37/16; c08b 37/00； C08B37/00 Search field: 536/ 103 Foreign references: separation and purification of etherified cyclodextrin JP58 173 102 10/983 536103.
Main examiners: Griffin, Ronald W. Lawyer, agent or company: Collard, Roy & gargano.
Statement: The contents of the statement are:
1. In the method for preparing heptaalkyl-[2,6-di -O- methyl]-beta-cyclodextrin by methylating beta-cyclodextrin in an organic medium, the improvement comprises methylating beta-cyclodextrin with dimethyl sulfate in an amount of 0/5 to 25 moles per 1 mole of beta-cyclodextrin/kloc-0. The temperature ranges from-10 to 0 C.
2. The method of claim 1, wherein the alkali metal hydroxide is used in powder form.
3. The method of claim 2, wherein the alkali metal hydroxide is NaOH with a particle size of 10 to100. m.
4. The method of claim 1, wherein one selected from dimethyl sulfoxide, dimethylformamide and mixtures thereof is used as the organic medium.
5. The method of claim 4, wherein the organic medium is dimethylformamide.
6. The method of claim 1, wherein 1-25 moles of the alkali metal hydroxide are used per1mole of.beta.-cyclodextrin.
7. The method of claim 6, wherein about 20 moles of the alkali metal hydroxide are used per 1 mole of.beta.-cyclodextrin.
8. The method of claim 1, wherein about 20 moles of the dimethyl sulfate are used per 1 mole of.beta.-cyclodextrin.
9. The process of claim 1, wherein the dimethyl sulfate is freshly distilled.
10. The method of claim 1, wherein the step of methylating beta-cyclodextrin has an alkylation degree of 14, whereby the preparation of heptaalkyl-[2,6-di -O- methyl]-beta-cyclodextrin can be carried out in one methylation step.