Synthesis and Characterization of a Series of 1-Aryl-4-[aryldiazenyl]- piperazines. Part I. Isomers of N-(2,3-Dimethylphenyl)-N’-(Aryldiazenyl)- Piperazines

Table 2: Physical data for series of 1-(4-methylbenzyl)-4-(aryldiazenyl)-piperazines (4).

		Crude		Recryst.	Crystal
No.	X	yield	mp(℃)	Recryst.	Appearance	IR (cm-1)
No.	X	(%)	mp(℃)	Solv.		IR (cm-1)
						(tri-sub)
4a	p-CN	99.6%	83-89	(a)	Dull orange	2225(CN)
4a	p-CN	99.6%	83-89	(a)	Powder	842&784(para)
				Hexanes &	Fibrous	1707(C=O)
				Hexanes &	Pale yellow	1274(C-O)
4b	p-CO2CH3	95.7%	118-119	cyclohexane	Needles	827&799(para)
4c	p-Br	70.6%	91-92	Isopropanol	Pale yellow	832&801(para)
4c	p-Br	70.6%	91-92	Isopropanol	Needles	832&801(para)
					Pink
4d	p-CH3	70.2%	93-94	Isopropanol	Plates	827&790(para)
					lustrous	1509 &
4e	p-NO2	90.5%	124-125	Ethanol	Red-brown	1379(NO2)
4e	p-NO2	90.5%	124-125	Ethanol	needles	848&795(para)
					Off-white	695 & 765
4f	H	93.2%	94.5-95.5	Isopropanol	Needles	(monosub)
4f	H	93.2%	94.5-95.5	Isopropanol		798(para)

(a) This compound was soluble in a variety of solvents, but it did not recrystallize from any of them.