▎ 摘　　要

NOVELTY - Continuous synthesis method of m-difluorobenzene based on microreactor involves (i) adding m-phenylenediamine and hydrochloric acid solutions to first microchannel reactor to react to prepare m-phenylenediamine hydrochloride solution, (ii) reacting the obtained m-phenylenediamine hydrochloride solution and dinitrogen trioxide in second microchannel reactor at -15 to -5 degrees C to prepare dichlorom-phenylenediamine diazonium salt solution, (iii) reacting dichlorom-phenylenediamine diazonium salt and fluoroboric acid in a tubular reactor at -15 to -5 degrees C, quickly centrifuging at the end of the reaction, washing and drying the obtained precipitate to obtain m-phenylenediamine difluoroborate, and concentrating and reusing the mother liquor after centrifugation, and (iv) mixing dichlorom-phenylenediamine diazonium salt and solvent in reactor, heating to decompose, subjecting the product in the reactor to atmospheric distillation, and collecting 82-84 degrees C fraction, which is the target product. USE - The method is useful for continuous synthesis method of m-difluorobenzene based on microreactor. ADVANTAGE - The method adopts dinitrogen trioxide as diazotizing agent, is environmentally-friendly, concentrates and reuses the centrifugal mother liquor in the reaction process to save cost and has no by-product and high reaction efficiency. DETAILED DESCRIPTION - Continuous synthesis method of m-difluorobenzene based on microreactor involves (i) adding m-phenylenediamine and hydrochloric acid solutions to first microchannel reactor to react to prepare m-phenylenediamine hydrochloride solution, (ii) reacting the obtained m-phenylenediamine hydrochloride solution and dinitrogen trioxide in second microchannel reactor at -15 to -5 degrees C to prepare dichlorom-phenylenediamine diazonium salt solution, (iii) reacting dichlorom-phenylenediamine diazonium salt and fluoroboric acid in a tubular reactor at -15 to -5 degrees C, quickly centrifuging at the end of the reaction, washing and drying the obtained precipitate to obtain m-phenylenediamine difluoroborate, and concentrating and reusing the mother liquor after centrifugation, and (iv) mixing dichlorom-phenylenediamine diazonium salt and solvent in reactor, heating to decompose, subjecting the product in the reactor to atmospheric distillation, and collecting 82-84 degrees C fraction, which is the target product, where the inner walls of the first microchannel reactor and the second microchannel reactor are both provided with a graphene/boron nitride nanosheet composite material layer of 10-20 mu m.