Method for preparing vitamin B1 intermediate by sodium modification

The invention discloses a method for preparing a vitamin B1 intermediate by sodium modification, which comprises the following steps: sequentially adding a liquid sodium methoxide and beta-aminopropionitrile into a closed reaction vessel; heating the reaction vessel to 35-55 DEG C, introducing carbon monoxide into the reaction vessel, and reacting to obtain a methyl formate product; and heating the reaction vessel to 55-85 DEG C, and reacting the methyl formate product with beta-aminopropionitrile under holding conditions to obtain the sodium modification product alpha-sodiumformacyl-beta-tetramidopropionitrile. The preparation method has the advantages of simple technical operation, energy saving and environment friendliness.