Preparation method of 5-( arylmethylene) meldrum's acid

Abstract

The invention relates to a preparation method of 5-(arylmethylene) meldrum's acid, which comprises the following steps of: a, dissolving aromatic aldehyde and aniline according to the mol rate of 1.0:(1.0-1.2) into water, wherein the aromatic aldehyde has a structural formula described in the specification, R is H, X (halogen), alkyl (such as CH3, C2H5), alkoxy (such as OCH3, OCH2CH3), OH, NO2 and CN; and b, respectively dissolving arylmethylene aniline obtained from the step a and meldrum's acid into an alcohol solution according to the mol ratio of (1.1-1.2):1.0 to obtain respective saturated solutions, then adding the alcohol saturated solution of the arylmethylene aniline into the alcohol saturated solution of the meldrum's acid, stirring for reacting for 3-4min, filtering after the reaction is ended, washing filter residue with water, drying and then recrystallizing to obtain the 5-(arylmethylene) meldrum's acid. The preparation method has the advantages of environment protection because of using water and alcohol as solvents, mild reaction condition, convenient posttreatment and higher yield of products.

Description

technical field The invention relates to a preparation method of 5-(aryl methylene) Michaelis acid. Background technique 5-(Arylene) Michaelis acid is a very active Michael addition reaction acceptor, which can be used as a reaction intermediate and a nucleophile to synthesize a series of heterogeneous compounds with potential medical value through D-A reaction and hetero D-A reaction. ring compound. Its English name is 5-Arylidene-2, 2-dimethyl-1, 3-dioxane-4, 6-diones (arylidene Meldrum's acids, AMAs). The chemical structural formula of 5-(aryl methylene) Michaelis acid is as follows: Wherein R=H, X (halogen), alkyl (such as: CH 3 , C 2 h 5 ), alkoxy (such as: OCH 3 , OCH 2 CH 3 ), OH, NO 2 , CN The synthetic route of 5-(arylmethylene) Michaelis acid reported in Document 1 (Tetrahedron Letters 42 2001 5203-5205) is shown in Scheme 1: using aromatic aldehyde 1 and Michaelis acid 2 as raw materials, using water as solvent in Knoevenagel condensation reaction w...

AI Technical Summary

Problems solved by technology

In this way, it cannot continue to carry out the cyclization reaction as a Michael addition reaction acceptor;

Secondly, the solvent used in the method provided in Document 2 is anhydrous benzene. It is known that benzene belongs to the first class of solvents in the ICH classification of chemical solvent toxicity, that is, it is a substance with strong toxicity to humans and relatively harmful to the environment;

The 3rd, the method that document 2 provides adopts pyrazole acetate as catalyst, and the reaction time is longer

Images