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

✍ Scribed by Georgeta Caraculacu; I. Zugrǎavescu; C. Ciobanu

• Publisher: Elsevier Science
• Year: 1975
• Tongue: English
• Weight: 163 KB
• Volume: 11
• Category: Article
• ISSN: 0014-3057
• DOI: 10.1016/0014-3057(75)90091-9

✦ Synopsis

Based on quantitative transformation of unsaturated polyesters into A2-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 ~oup. 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 A2-pyrazoline polyamide.

In a previous paper [1] we described the heterocyclization reaction carried out by a 3 + 2 dipolar cycloaddition on some reactive polymers such as unsaturated polyesters. New polyesters bearing heterorings, namely A2-pyrazoline rings, on the backbone were obtained [see Eqn. (1)]: