Method for preparing 2-arylmalonic acid derivative and intermediate, and use thereof

A method for preparing a 2-arylmalonic acid derivative of formula (3), comprising:

• (1) subjecting a compound (1) to an isomerization reaction in the presence of a base to obtain an intermediate (2), as shown in the following reaction scheme:
• wherein the base is selected from the group consisting of an alkali metal hydroxide, an alkali metal alcoholate and a combination thereof;
• and
• (2) subjecting the intermediate (2) to a halogenation reaction in the presence of a halogenating agent to produce a halogenated product, and subjecting the halogenated product to a dehydrohalogenation-aromatization reaction under a temperature of 110-150° C. to obtain the 2-arylmalonic acid derivative (3), as shown in the following reaction scheme:
• wherein the halogenating agent is selected from the group consisting of an elemental halogen and sulfuryl chloride;
• wherein R1, R2, R3, R4 and R5 are each independently hydrogen or a C1-C4 alkyl group;
• Y1 and Y2 are each independently cyano, —COOMe or —COOEt.