|Heitz, W; Kampschulte, U; Bruegging, W; Schmidt, HW: Preparation of difunctional stilbenes as liquid crystal polyester monomers, DE 3719578, Bayer AG Germany|
2,5-X2C6H3CH:CHR (I; R = aryl; X = OH, NH2, NHCOR1, CO2H, OR1, CO2R2; R1, R2 = C1-6 alkyl) were prepd. by condensation of 2,5-X2C6H3Y (Y = halo) with vinylaroms. Thus, bromohydroquinone diacetate was stirred for 17 h at 100_ with PhCH:CH2 in Et3N contg. Pd(OAc)2 and (2-MeC6H4)3P under 5 bar N to give 48% 2,5-(AcO)2C6H3CH:CHPh.