2

4-Difluorobenzaldehyde was synthesized from 1

3-difluorobenzene and carbon monoxide with AlCl3 and HCl as catalyst in CO atmosphere at a pressure in the range of 1.5 MPa. Effects on the converting ratio and yield were investigated. The results showed that the optimum technological conditions should be that n（1

3-difluorobenzene）∶n（AlCl3）=1.0∶1.0

the reaction temperature was 60℃

amount of HCl was 1.0% of total mass of reation mixture

and the reation time was 20 hours. The selectivity of 2

4-difluorobenzaldehyde from 1

3-difluorobenzene was up to the purity of the refined product w(2

4-difluorobenzaldehyde) ≥98.81%.