Synthesis and characterization of chiral polyamides derived from glycine and (S)-5-amino-4-methoxypentanoic acid

✍ Scribed by Hernan A. Orgueira; Manuel Bueno; Jose Luis Funes; Juan A. Galbis; Oscar Varela

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 161 KB
• Volume: 36
• Category: Article
• ISSN: 0887-624X
• DOI: 10.1002/(sici)1099-0518(19981115)36:15<2741::aid-pola10>3.0.co;2-e

✦ Synopsis

Stereoregular, enantiomerically pure, chiral polyamides of the -AB-type, containing a natural (glycine) and a synthetic [(S)-5-amino-4-methoxypentanoic acid (AMP)] component have been prepared by the active ester polycondensation method. Thus, polyamide 7 was obtained by polycondensation of the conveniently activated H 2 NGly-AMPCO 2 R unit (6). In this reaction, 7 appeared accompanied by a considerable amount of cyclic (Gly-AMP) 2 (8), which makes the isolation and purification of 7 difficult. The formation of cyclic byproducts could be avoided by preparing and polymerizing the oligoamide H 2 NGly-AMP-AMPCO 2 R (11), which has the terminal carboxyl group activated as the pentachlorophenyl ester. The resulting polyamide (12) was obtained in 85% yield and free of macrolactams, such as 8. The new polyamides 7 and 12 were characterized by elemental analysis and infrared and 1 H-and 13 C-nuclear magnetic resonance spectroscopies. Thermal studies revealed that 12 is crystalline and yields films with spherulitic texture by slow evaporation of formic acid solutions.