Synthesis Improve Of FSB In Molecular Probe And Synthesis Of Styrylben Derivates

(E,E)-1-Fluoro-2,5-bis（3-hydroxycarbonyl-4-hydroxy）styrylbenzene （FSB）is the only NMR-molecule probe employed in clinical use,which plays very important role in taking precautions against cancers and checking,tracking Alzheimer’s and other cancers.Only one literature about synethesis of FSB was available at present and only 0.68%yield was reported.So the improvement of synthesis of FSB is very important.There are two parts in the present paper:the first part is about the synthesis improvement of three intermediates of FSB with environment-friendly and economical reactants.Synthesis improvement aobut the three intermediates,i.e.,2-fluoro-p-xylene, 3-methoxycarbonyl-4-methoxybenzaldehyde and 1-fluoro-2,5-bis （bromomentyl）benzene were described.Especially,the novel method about bromide-substituted for 1-fluoro-2,5-bis（bromomentyl）benzene by NaBrO₃/NaHSO₃ was introduced for the first time in the present paper.The above reaction steps are simple and do no harm to environment.The yields of three intermediates were improved from 15%,65%,43%to 73.5%, 70.0%and 72.0%,respectively.The second part is about the preparation of ten styrylben derivatives which are structure-similar to FSB by wittig reagent and two kinds of aldehyde with donated or absorbed electron group.The aldehydes with absorbed electron group were found to own higher reaction acitivity with wittig reagent than the aldehydes with donated electron group.