Methyl 1,2,3,4-tetrahydroquinoxaline-6-carboxylate and preparation method thereof

The invention discloses methyl 1,2,3,4-tetrahydroquinoxaline-6-carboxylate and a preparation method thereof. The structure formula of methyl 1,2,3,4-tetrahydroquinoxaline-6-carboxylate is defined in the specification. The preparation method comprises the following steps: firstly, a cheap starting raw material 3,4-diaminobenzoic acid is suspended in anhydrous methanol, and then methyl 3,4-diaminobenzoate is obtained by catalytic esterification with concentrated sulfuric acid; secondly, quinoxaline-6-methyl carboxylate is synthesized by cyclic condensation of methyl 3,4-diaminobenzoate with [1,4] dioxane-2,3-diol; and finally, quinoxaline-6-methyl carboxylate is reduced by a common reductant sodium borohydride to obtain methyl 1,2,3,4-tetrahydroquinoxaline-6-carboxylate. The preparation route and method have the advantages of cheap reagents, mild reaction conditions, and easy purification treatment of intermediate steps and products. Provided is the new method for preparing methyl 1,2,3,4-tetrahydroquinoxaline-