水溶剂中K2CO3催化合成2-氨基-4H-色烯衍生物

Synthesis of 2-Amino-4H-Chromene Derivatives Catalyzed by K2CO3 at Warer

摘要:

以取代水杨醛和氰乙酸酯为原料，以水或约50%乙醇为溶剂，以K2CO3为催化剂合成了6个2-氨基-4H-色烯衍生物。以水杨醛与氰乙酸乙酯的反应为模板反应，通过单因素实验探讨了反应各因素对产率的影响。结果表明：水杨醛10mmol，水杨醛与氰乙酸酯的摩尔比为1:2.5，K2CO3用量1mmol，20mL水作溶剂，40℃恒温水浴中搅拌反应40min，获得产率高达94.2%的目标产物，催化剂溶液重复使用5次，其催化活性下降不明显。当以氰乙酸甲酯代替氰乙酸乙酯反应，得到相应目标物的产率为90.1%；当以固态5-溴(或氯)-水杨醛代替水杨醛与氰乙酸酯在20mL约50%乙醇作溶剂中反应时，获得相应目标物的产率为78.9%~86.6%。

Abstract:

Six 2-amino-4H-chromene derivatives were synthesized from the substituted salicylaldehyde with cyanoacetate in the presence of water or 50% ethanol solution catalyzed by K2CO3. With salicylaldehyde and ethyl cyanoacetate as template reaction, the effect of various factors on the yield of the reaction were investigated by single factor experiments. The results showed that the goal product was obtained 94.2% yield within based on 10 mmol of salicylaldehyde, molar ratio of salicylaldehyde to ethyl cyanoacetate 1︰2.5, dosage of K2CO3 1 mmol, 20mL water as solvent and reaction time 40 min in water bath of 40℃ constant temperature. The catalyst solution can be resued for 5 cycles without significant loss of activity. When methyl cyanoacetate displaces ethyl cyanoacetate, the corresponding goal product was synthesized with the yield 90.1%. When solid 5-bromo(or chloro)-salicylaldehyde displaces salicylaldehyde at 20mL 50% ethanol solution as solvent, the corresponding target products were synthesized with the yield from 78.9%~86.6%.