The application discloses a method for synthesizing benoxacor, and belongs to the technical field of chemical
organic synthesis. The method comprises the following steps: taking DMF as a
solvent, fully reacting ortho-
nitrophenol with monochloroacetone and alkali at a certain temperature, centrifuging after the reaction is completed, obtaining a first
filter cake and a DMF solution of 2-nitro-2-phenoxypropanone, removing part of the DMF through
vacuum distillation, detecting the content of
chloroacetone in the gas chromatograph, and adjusting the
mass concentration of the 2-nitro-2-phenoxypropanone DMF solution to 10-20% after the content of
chloroacetone is detected to be lower than 0.02% by using the area normalization method; then, adding
Raney nickel into the 2-nitro-2-phenoxypropanone DMF solution, and performing
hydrogenation reaction by passing
hydrogen; after the reaction is completed, the upper
clear liquid is extracted, and 3,4-dihydro-3-methyl-2H-1,4-benzoxazine DMF solution is obtained through
filtration; then, an acid-binding agent alkali is added, and
acylation reaction is performed by dropwise adding dichloroacetyl
chloride, so as to synthesize benoxacor. The method can greatly simplify the operation process of frequently changing solvents in the process of synthesizing benoxacor, and can avoid the generation of a large amount of waste brine.