Syntheses of novel calix[4]arene derivatives with polyaza groups

The reaction of p-tert-butylcalix[4]-1,3-substituted benzaldehyde derivative 1 with salicylic hydrazide, nicotinic hydrazide or isonicotinic hydrazide gave a series of novel ring opening calix[4]arene derivatives 2a similar to 2c containing polyaza groups in the yields of 88%, 85% and 90%, respectively. Treatment of compound 1 with oxalyl dihydrazide, malonic dihydrazide and adipic dihydrazide, afforded novel bridged calix[4]arene derivatives 3a similar to 3c substituted with polyaza groups in the yields of 86%, 89% and 90%, respectively. All new compounds were characterized by elemental analyses, ESI-MS, H-1 NMR spectra, which indicated that calix[4]arene units were 1,3-substituted pattern with cone conformation.