Calix4arene derivatives containing two or four O -propargyl moieties are capable of undergoing reductive depropargylation in the presence of hydrazine hydrate. The propargyl groups are removed in the form of 4,5-dihydro-1 H -pyrazoles, which allowed proposing a reasonable mechanism for the depropargylation. The propargyl group can be used as the protection for the selective nitration at the distal positions of the upper rim of di- O -propargyl-substituted calix4arene and p - tert -butylcalix4arene. The reduction of nitro group at the upper rim proceeds along with the depropargylation upon the addition of a nickel catalyst to the reaction mixture with hydrazine hydrate, which leads to calixarenamines containing free hydroxy groups.