METHOD FOR PREPARING 4-SUBSTITUTED ALKYL-3-OXOBUTANOATES Russian patent published in 2005 - IPC

FIELD: organic chemistry, chemical technology.

SUBSTANCE: invention relates to synthesis of 1,3-dicarbonyl compounds and to a new method for preparing 4-substituted alkyl-3-oxobutanoates of the formula: wherein: R is C₆H₅CH₂, 2-F-6-ClC₆H₃CH₂, 2,6-Cl₂C₆H₃CH₂, 1-C₁₀H₇CH₂, Ph₂CH; Alk is Me; R is 1-AdCH₂; Alk is i-Pr that are used precursors of antiviral agents of pyrimidine order. Method involves acylation of 2,2-dimethyl-1,3-dioxane-4,6-dione with acyl chlorides in dichloromethane in the presence of triethylamine followed by alcoholysis of 5-(1-hydroxyethylidene)-2,2-dimethyl-1,3-dioxane-4,6-dione wherein acylation is carried out with acyl chlorides in the presence of trimethylsilyl chloride in the mole ratio 2,2-dimethyl-1,3-dioxane-4,6-dione : acyl chloride : trimethylsilyl chloride : triethylamine = (1-2):1:1.1:3.5, respectively, with formation of an intermediate product 5-[1-(trimethylsilyloxy)ethylidene]-2,2-dimethyl-1,3-dioxane-4,6-dione that is subjected for hydrolysis with formation of 5-(1-hydroxyethylidene)-2,2-dimethyl-1,3-dioxane-4,6-dione and its following alcoholysis and formation of the end product. Method provides enhancing yield and purity of claimed compounds.

EFFECT: improved method for preparing.

2 cl, 8 ex