4-氟苯甲醛的合成工艺研究

Synthesis of 4-Fluorobenzaldehyde

以4-氯苯甲醛(PCAD)和无水氟化钾为原料,采用卤素交换氟化反应,反应蒸馏技术一步合成4-氟苯甲醛(PFAD)。考察了溶剂、催化剂、投料比对反应的影响,得出最佳工艺条件为以1,3-二甲基丙撑脲为溶剂,四苯基二氟化氢膦盐(Ph4PHF2)为催化剂,n(KF):n(PCAD):n(Ph4PHF2)=3:1:0.1。在此条件下,反应与蒸馏同时进行,4-氟苯甲醛的收率可达90.6%。

Using halogen-exchange fluorination and reactive distillation,4-fluorobenzaldehyde was synthesized from 4-chlorobenzaldehyde and anhydrous potassium fluoride.The effects of solvents,catalysis and feed ratio were discussed.The results showed that the optimum conditions should be N,N’-dimethylpropyleneurea as solvent,Ph4PHF2 as catalyst,n（KF）： n（PCAD）：n（Ph4PHF2）=3：1：0.1,reaction and distillation simultaneously,the yield of 4-fluorobenzaldehyde was 90.6%.