Table 3: Physical data for series of 1-(2-methylbenzyl)-4-(aryldiazenyl)-piperazines (5).

Overall Recryst. Crystal
No. X yield mp(℃) Solvent IR (cm-1)
(%) appearance
Iso- Off-white 2218(CN)
5a p-CN 47% 73-74 Propanol prisms 840(para)
745(ortho)
Iso- Pale pink 1714(C=O)
Propanol Needles 1274(C-O)
859(para)
5b p-CO2CH3 52% 97.5-98.5 746(ortho)
5c p-Br 35% 65-66 Ethanol Lustrous 830(para)
Brown plates 744(ortho)
Ethanol Red-brown 1509 &
Prisms 1378(NO2)
853(para)
5d p-NO2 66.5% 92.5-93 745(ortho)
Hexanes Fibrous 693 & 761
5e H 72% 71-73 (a) Pale yellow (mono-sub)
Prisms 743(ortho)

(a) By trituration