Table 1: Physical data for the N-(2,3-dimethylphenyl)-N’-(aryl-diazenyl)-piperazines (3).

No X Crude Mp (℃) Recryst. Crystal IR (cm-1)
yield Solv. Appearance
(%)
3a p-CN 87.3% 147-148 Ethanol Red-brown 2220(CN)
Needles 848(para)
785&724
(1,2,3-trisub)
3b p-CO2CH3 63.7% 155-157 Ethanol Small orange 1714(C=O)
Plates 1275(C-O)
856(para)
780&724
(tri-sub)
3c p-Br 100.0% 103-103.5 Ethanol Fibrous 833(para)
Off-white 782&719
Plates (tri-sub)
3d p-CH3 81.8% 132-132.5 Ethanol Needles 828(para)
788&723
(tri-sub)
3e p-NO2 100.0% 152-155 Ethanol Red-brown 1507 &
Needles 1341(NO2)
851(para)
787&721
(tri-sub)
3f H 57.7% 102-102.5 Ethanol Lustrous 697 & 763
Gold plates (mono-sub)
788&724