Nucleoside preparation technology by using solvent-free melting method and catalyst used thereby

Abstract

The invention relates to a catalyst used by a nucleoside preparation technology by using a solvent-free melting method, which is characterized in that the catalyst takes acidic or meta-acidic ionic liquid as the catalyst; the ionic liquid catalyst is quaternary ammonium salt type ionic liquid at constant temperature. The invention also discloses a nucleoside preparation technology utilizing the catalyst by using a solvent-free melting method, which is characterized in that carbohydrate derivatives and purines or miazines protected by silicon armour and other heterocyclic compounds of the same molar weights are heated to a melting state to prepare the corresponding nucleoside under the condition that the ionic liquid catalyst is used for catalysis. The invention has the advantages that the raw materials of the catalyst have wide sources and are easy acquired; the catalyst is taken as the technological catalyst for preparing various nucleosides by utilizing the solvent-free melting method, the reaction substrate is easily converted into the melting state because the catalyst is liquid at the constant temperature and has high boiling point; the heating temperature is low; the reaction is stable; and the carbonization degree of reaction mixture is low to be beneficial to the enhancement of the yield.

Description

technical field [0001] The invention relates to a method for preparing nucleosides, in particular to a process for preparing nucleosides by a solventless melting method; the invention also relates to a catalyst used in the aforementioned process. Background technique [0002] The method of preparing nucleosides by melting method is usually used to melt and stir almost equimolar amounts of acyl-protected sugar derivatives and other heterocyclic compounds (often called nucleoside bases) such as purines or pyrimidines, then cool slightly and add catalytic The Lewis acid is mixed and then heated to a molten state. The reaction temperature is relatively high and the range is wide, usually between 130-195°C. The feeding method can also mix the two main reaction raw materials and a small amount of catalyst Lewis acid together, and then heat it to a molten state. Under negative pressure (the requirement for negative pressure is not high, because the reaction temperature is high, wa...

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Problems solved by technology

[0004] Although the above melting method for preparing nucleosides avoids the use of the Silyl-Hilbert-Johnson method (see: Vorbrueggen H, Run-Pohlenz C. Synthesis of Nucleosides, in Organic Reaction, Paquette LA, et al.eds, John Wiley & Sons: New York, 2000, Vol 55: 154-284), Lewis acid catalysts such as heavy metal inorganic salts, reduce the pollution to the environment, but the types and quantities of catalysts that can be used in the melting method---acid compounds are still limited, and cannot adapt Protected Sugars and Nucleobase Variation Requirements

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