The heterocyclization of some reactive polymers by a 3 + 2 dipolar cyclo-addition reaction—II. Polyamides and polyhydrazides

Based on quantitative transformation of unsaturated polyesters into Δ₂-pyrazoline polymers when reacted with 1,3-dipoles, attempts were made to apply the same reaction to unsaturated polyamides and polyhydrazides having double bonds conjugated with a carbonyl group. One could not obtain heterocyclic polymers because of factors discussed in the paper. The presence of an active hydrogen atom in the molecule of polyamide or polyhydrazide causes a decrease of the dipolarophile capacity of the double bond. Substitution of these hydrogen atoms, both in model compounds and polymers, leads to the expected results. Thus N-alkylpolyamide was quantitatively transformed into the Δ₂-pyrazoline polyamide.