Liquid crystals containing phenylpyrimidine units are the fascination condensed state of soft matter with unique electrical, optical and mechanical properties. In this paper, a novel and efficient route was reported for the synthesis of N-(3-(dimethylamino)-2-(4-ethoxyphenyl)allylidene)-N-methylmethanaminium perchlorate by the WillgerodtKindler reaction, which can be further applied to prepare liquid crystals containing phenylpyrimidine units. The product was confirmed by 1HNMR, MS, FT-IR and elemental analysis. The experimental conditions of the Willgerodt-Kindler reaction were also studied and the results show that the yield ofp-ethoxyphenyl-acetic acid increased remarkably with a reaction time up to 60 min, then decreased due to carbonization. On the other hand, the yield was also influenced by microwave power. It increased from 20.6 % to 78.8 % with a rise in the microwave power from 250 W to 450 W, but the product was carbonized at 640 W.