Single step microwave induced process for the preparation of substituted stilbenes and its analogs
申请人:Sinha Kumar Arun
公开号:US20070276172A1
公开(公告)日:2007-11-29
The present invention relates to a single step, microwave induced process for the preparation of substituted stilbenes and its analogs. Particularly, provides a method for the preparation of commercially important 2- or 4-hydroxy substituted stilbenes in one pot utilizing cheaper substrates in the form of 2- or 4-hydroxy substituted arylaldehyde and/or phenylacetic acids as well as regents in the form of base such as collidine, triethylamine, pyridine, piperidine, sodium acetate, ammonium acetate, imidazole, methyl imidazoles and the like and/or acid such as formic acid, acetic acid, propionic acid and the like for a reaction time varying from 1 min-16 hrs depending upon microwave or conventional heating, without using decarboxylating agents with yield varying from 37-66% depending upon the base and/or acid, solvent and substrate used. It is important to mention that the presence of hydroxy substitution at 2- or 4-position of arylaldehyde and/or aryl acetic acid is essential requirements towards formation of stilbenes in one step.
本发明涉及一种单步微波诱导过程,用于制备取代苯乙烯及其类似物。特别地,提供了一种在一个反应器中利用更便宜的底物,如2-或4-羟基取代芳基醛和/或苯乙酸,以及碱性试剂,如哌啶,三乙胺,吡啶,哌啶,乙酸钠,醋酸铵,咪唑,甲基咪唑等和/或酸性试剂,如甲酸,醋酸,丙酸等,反应时间从1分钟到16小时不等,取决于微波或常规加热,而不使用脱羧试剂,产率从37%到66%不等,取决于所使用的碱性和/或酸性试剂,溶剂和底物。需要指出的是,在芳基醛和/或芳基乙酸的2-或4-位存在羟基取代是形成单步合成苯乙烯的必要条件。