2,6-Difluorobenzaldehyde

• 5-Cyano-6-(2,6-difluorophenyl)-5,6-dihydro-2-thiouracil via one-pot cyclocondensation reaction with ethyl cyanoacetate and thiourea.
• 1-(2,6-Difluorobenzyl)-2-(2,6-difluorophenyl)-benzimidazole by reacting with 1,2-phenylenediamine in the presence of a catalytic amount of p-toluenesulfonic acid.
• (3E)-4-(2,6-Difluorophenyl)-3-buten-2-one by Wittig olefination reaction with acetylmethylidenetriphenyl phosphorane.
• Methyl 4-fluorobenzo[b]thiophene-2-carboxylate by treating with methyl thioglycolate in the presence of K₂CO₃.

83-38-5

437-81-0

The general procedure for the synthesis of 2,6-dichlorobenzaldehyde from 2,6-dichlorobenzaldehyde was as follows: first, 34.8 g (0.6 mol) of potassium fluoride (KF) was dissolved in 250 mL of cyclobutanesulfone under nitrogen protection and stirred at 100 °C for 2 h. The water was removed by azeotropic distillation. Subsequently, 20 g (0.11 mol) of 2,6-dichlorobenzaldehyde and 2.8 g (6.68 mmol) of tetraphenylphosphonium bromide were added to this anhydrous mixture and the reaction mixture was heated to 180 °C and kept overnight. Upon completion of the reaction, the solid product was washed with ethyl acetate and the solvent was removed by aqueous pressure evaporation. Finally, the target product 2,6-difluorobenzaldehyde was purified by vacuum evaporation (24 mbar, 85-86 °C) in 77% yield.