Method for synthesizing 3-spiro three-membered ring indolinone derivative

A method for synthesizing a 3-spiro three-membered ring indolinone derivative, comprising steps of:

• under a protective atmosphere, reacting a compound of formula (I) or formula (III) at 20-60° C. in the presence of an additive and an organic base in an organic solvent, to obtain a compound of formula (II) or formula (IV) after the reaction is complete, wherein the additive is N-bromosuccinimide (NBS) or N-chlorosuccinimide (NCS);
• and
• the reaction routes are as follows, wherein the formula (I) is exclusive of the formula (III):
• wherein in formulas (I)-(IV), R1 is selected from hydrogen, C1-C4 alkyl or halo;
• R2 is hydrogen, C1-C4 alkyl, benzyl or phenyl;
• Ar is selected from phenyl, substituted phenyl or thienyl, in which the substituent on the substituted phenyl is selected from the group consisting of halo, C1-C4 alkyl, C1-C4 alkoxy or any combination thereof;
• and X is chloro or bromo.