Method for preparation of organofluoro compounds in alcohol solvents

Abstract

The present invention relates to a method for preparation of organofluoro compounds containing radioactive isotope fluorine-18. More particularly, the present invention relates to a method for preparation of organofluoro compound [18F]florbetaben or [18F]AV-45 having <Chemistry Formula 11> and <Chemistry Formula 12>, respectively, by reacting fluorine salt containing radioactive isotope fluorine-18 with alkyl halide or alkyl sulfonate in the presence of alcohol of Chemistry Formula 1 as a solvent to obtain high yield of organofluoro compound. Synthesis reaction according to the present invention may be carried out under mild condition to give high yield of the organofluoro compounds and the reaction time is decreased, and thereby is suitable for the mass production of the organofluoro compounds.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001]This patent application is a continuation-in-part of U.S. patent application Ser. No. 11 / 720,393 filed May 29, 2007, which in turn claims the benefit of priority from Korean Patent Application Nos. 10-2004-0106553 filed Dec. 15, 2004, and 10-2005-0084411 filed Sep. 10, 2005, through PCT Application Serial No. PCT / KR2005 / 004228 filed Dec. 9, 2005, the contents of which are incorporated herein by reference.TECHNICAL FIELD [0002]The present invention relates to a method for preparation of organofluoro compounds containing fluorine-18, a radioactive isotope of fluorine. More particularly, the present invention relates to a method for preparation of organofluoro compounds to obtain the organofluoro compounds in a high yield by reacting fluorine salt containing radioactive fluorine-18 with alkyl halide or alkyl sulfonate in the presence of alcohol of the Chemistry Formula 1 as a solvent.(wherein R1, R2 and R3 are hydrogen or C1˜C18 alkyl group...

AI Technical Summary

Benefits of technology

[0015]According to the present invention, the organofluoro compounds as major products may be selectively prepared in the yield above 90% by suppressing the formation of the side reactions with the use of alcohol as reaction solvent. The alcohol solvent increases nucleophilic substitution reactivity of the fluorine salt by weakening the ionic bonds between metal cations and fluorine anions through the formation of hydrogen bonds with fluorine metal salts, thereby the problem of the low reactivity due to the strong ionic bond of fluorine in a conventional method may be overcome, reaction time maybe shortened by increased reactivity and reaction rate of the fluorine salt, and the formation of side products due to the influence of basicity may be suppressed by weakening the basicity of the fluoride through the hydrogen bond of the fluoride.

Problems solved by technology

It is known that alcohol, a protic solvent, is not suitable for the nucleophilic fluorination reaction.

However, this preparation method has disadvantages of low yield and long reaction time at high reaction temperature above 140° C., because reactivity is low due to the low solubility of potassium fluoride.

However, this process has disadvantages that 18-crown-6 ether is expensive, long reaction time is required and a large amount of alkene is produced as a side product because fluoride acts as base.

However, tetrabutylammonium fluoride hydrate has a problem that a large amount of alcohol, which is a side product caused by water, is produced, and alkene is produced as another side product due to the high basicity of tetrabutylammonium fluoride.

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