Table 2: Summary of physical and IR spectroscopic data of the 1-(4-fluorophenyl)-4-(2-aryl-1-diazenyl)-piperazine series (13).

Series #	X	% Yield	M.P. (°C)	Recr. Solv.	Crystal appearance	IR (cm-1)
13a	p-CO2CH3	99	151.8 - 152.4	Ethanol	Orange Fibrous Needles	OOP C=O C-O	865 1710 1277
13b	p-Br	99	185.9 - 186.5	Ethanol	Tiny pale Yellow needles	OOP	837
13c	p-CH3	72	171.9 - 172.8	Ethanol	Pale flesh-colored plates	OOP	814