METHOD FOR PREPARING 2,3,4-TRIMETHOXYBENZALDEHYDE Russian patent published in 2004 - IPC

FIELD: organic chemistry, chemical technology.

SUBSTANCE: invention relates to the improved method for preparing 2,3,4-trimethoxybenzaldehyde used as an intermediate substance for synthesis of medicinal preparations. Method involves interaction of 1,2,3-trimethoxybenzene with dimethylformamide and phosphorus oxychloride and treatment of reaction mixture with water. Reaction is carried out at 80-85 C and product is isolated by either extraction with organic solvent and washing out extract with alkali and sodium chloride aqueous solutions successively, evaporation of solvent and diluting a residue with aliphatic solvent or by crystallization in treatment with water directly, filtering off crystals, their washing out with water and re-pulping crystals in water. Proposed method allows elimination of vacuum-rectification and to obtain the end product with the content 99.5% and the yield about 75%.

EFFECT: improved preparing method, enhanced purity and yield.

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