The Friedel-Crafts acylation of 2-(biphenyl-4-yl)-5-phenyl-1,3,4-oxadiazole (PBD) with hippuryl chloride has been used to prepare the derivative V which on cyclization with POCl3 or P4S10 gives the respective oxazole (or thiazole) derivative of PBD, XIa or XIb. The reaction of carboxylic acid II with 4-(o-aminoacetyl)biphenyl in the presence of CDI gives N-acyl-α-aminoketone VII; the analogous compound VI has been prepared by acylating of o-aminoacetophenone with acyl chloride III. The cyclization of these compounds gives bifluorophores Xa - Xd.
对2-(联苯基-4-基)-5-苯基-1,3,4-噁二唑(PBD)进行弗里德尔-克拉夫斯酰化反应,使用对甲基苯甲酰氯制备衍生物V,该衍生物在与POCl3或P4S10环化反应后形成PBD的相应噁唑(或噻唑)衍生物XIa或XIb。将羧酸II与4-(o-氨基乙酰)联苯在CDI存在下反应,得到N-酰基-α-氨基酮VII;类似的化合物VI通过对o-氨基苯乙酮与酰氯III进行酰化反应制备。这些化合物的环化反应形成双氟光团Xa - Xd。