Synthesis and Characterization of a Series of 1-Aryl-4-[Aryldiazenyl]-piperazines. Part II1. 1-Aryl-4-(2-Aryl-1-Diazenyl)-piperazines with Fluoro-, chloro-, Methyl-, Cyano- and Acetyl Substituents in The 1-Aryl Group

Table 13: Summary of physical and IR spectroscopic data of the 1-(2-pyridyl)-4-(2-aryl-1-diazenyl)-piperazine series (18).

Series #	X	% Yield	M.P. (°C)	Recr. Solv.	Crystal Appearance	IR (cm^-1)
18a	p-NO₂	71	197.5 - 198.2	Ethanol	Tiny orange-red prisms	OOP NO₂	855 1333, 1504
18b	p-CN	69	150.2 - 151.1	Ethanol	Lustrous creamy- orange plates	OOP C≡N	835 2217
18c	3-py	79	Oil	Oil	Lustrous metallic needles	OOP	810
18d	p-CO₂CH₃	59	146.3 - 147.0	Ethanol	Yellow prisms	OOP C=O C-O	855 1710 1282
18e	p-COCH₃	61	166.4 - 166.8	Ethanol	Buff prisms	OOP C=O	850 1672
18f	p-CH₃	55	111.7 - 112.3	Ethanol	Off-white needles	OOP	844
18g	o-Br	74	Oil	Oil	-	OOP	756
18h	H	51	99.4 - 100.4	Ethanol	Large lustrous pale brown plates	OOP	758