相转移催化合成4-{2-[N-甲基-N-(2-吡啶基)]氨基乙氧基}苯甲醛

Synthesis of 4-{ 2-[N-methyl-N-( 2-pyridyl) ]aminoethoxy} benzaldehyde by phase-transfer catalysis

以2-氯吡啶(1)、2-甲氨基乙醇(2)和4-氟苯甲醛(4)为主要原料,经2步反应合成了4-{2-[N-甲基-N-(2-吡啶基)氨基乙氧基]}苯甲醛(5)。第1步反应n(2)∶n(1)=4∶1,反应温度160℃,反应时间约6 h,采用减压蒸馏进行后处理,2-[N-甲基-N-(2-吡啶基)氨基]乙醇(3)的收率在93%以上,过量2的回收率在97%以上,回收的2可以重复使用。第2步反应用氢氧化钠做碱性试剂,用甲苯和水分别做为两相的溶剂,在相转移催化剂CTAB作用下进行,经优化后5的收率可达90%以上。2步反应总收率达83%以上。

4 - { 2 - [ N-Methyl-N- （2-pyridyl） ] aminoethoxy t benzaldehyde （5） was synthesized by a two-steps process with 2-chloropyr- idine （ 1 ）, 2- （methylamino） ethanol （ 2 ）, and 4-fluorobenzaldehyde （ 4 ） as principal raw materials. In first step of the process, the mole ratio of 2 to 1 was 4：1, reaction temperature 160℃, reaction time about 6 h, and adopted vacuum distillation in work-up proce- dure. Under such conditions, the yield of 2- [ N-methyl-N- （2-pyridyl） amino ] ethanol （3） was more than 93 %, the rate of recovery of the excess 2 was more than 97% ,and recovered 2 could be cyclically used. The second step of process was carried out with sodium hydroxide as basic reagent, toluene and water as solvent of two phases respectively, CTAB as phase-transfer catalyst, gave 5 in more than 90% yield under optimal conditions. The above two steps gave 5 in more than 83% overall yield.