摘要
以邻羟基苯乙醚 (乙基愈创木酚 )和乙醛酸为原料 ,在碱性条件下发生缩合反应 ,合成了 3 乙氧基 4 羟基扁桃酸 ,此物质是以乙醛酸法制备乙基香兰素的中间体。通过对反应条件的优化发现 ,此合成反应的最佳反应温度为 5 0～ 60℃ ,最佳碱浓度范围为 2 0～ 4 4M ,最佳缩合反应时间为 3 5～ 8h。同时采用碱溶液的部分滴加方式 ,可使缩合反应在较短的时间内完成 ,收率达 80 %以上 ,未反应的乙基愈创木酚可以回收。
As an intermediate for preparing ethyl vanillin derived from glyoxylic acid, 3-ethoxy-4-hydroxymandelic acid (EHMA) is synthesized based on condensation of guaethol and glyoxylic acid in alkaline aqueous solution. Based on optimization, optimal reaction conditions are obtained i.e. reaction temperature is 50～60℃; reaction time 3 5～8h; concentration of alkali 2 0～4 4M. In addition, the yield of EHMA could reach over 80% in shorter period by partially adding of alkaline solution gradually. The un-reacted guaethol could be recovered.
出处
《精细与专用化学品》
CAS
2004年第11期24-25,共2页
Fine and Specialty Chemicals
