Síntese, avaliação antimicrobiana e estudo topológico e energético de 2-oxoetiltereftalatos simétricos e não simétricos a partir de garrafas PET pós-consumo

Abstract

This work describes the synthesis of ten non-symmetric and four symmetric 2- oxoethylphthalate compounds, derived from potassium terephthalate, which was obtained from the depolymerization reaction of post-consumption polyethylene terephthalate (PET) bottles. The choice of post-consumer PET bottles as raw material comes from the possibility of adding value to new substances obtained from recyclable sources, which, in addition, are candidates for antibacterial and antifungal agents, as well as reducing residues in the environment. environment. The first step for both symmetrical and non-symmetric 2-Oxoethylphthalate series was through (i) preparation of potassium terephthalate (2) from the depolymerization reaction of postconsumer PET bottles (1) in 90% of Yield. Non-symmetric 2-oxoethyl terephthalates (8a-j) were synthesized through six steps: (ii) acid hydrolysis reaction of recycled potassium terephthalate (2) in 100% yield; (iii) esterification reaction of terephthalic acid (3) with methanol in 80% yield; (iv) reaction of basic monohydrolysis of methyl terephthalate (4) in 77% yield; (v) acetylation reaction of aromatic amines with chloroacetyl chloride in 76-95% yield; and (vi) alkylating the methyl terephthalate salt (5) with 2-chloro-N-arylacetamides (6a-j) in 52-98% yield. Symmetric 2- oxoethylterephthalates (9a-d) were synthesized through three steps: (ii) esterification reaction of chloroacetic acid with different alkyl alcohols in 89-93% yield; and (iii) alkylation reaction of recycled potassium terephthalate (2) with alkylated 2- chloroacetates (7a-d) in 66-78% yield. Intermediate and final compounds were characterized by IR spectroscopic techniques, 1H and 13C NMR (uni and twodimensional) and mass spectrometry (CG-MS and ESI-MS). In the 80-0.31 µg.mL-1 concentration range, the final compounds (8a-j and 9a-d) showed no antifungal (yeast and filamentous fungi) and antibacterial activity in vitro. The compounds obtained in the crystalline form (8h and 9a-b) were submitted to single crystal X-ray diffraction analysis, through which, together with the supramolecular cluster methodology and quantum mechanics calculations of the density functional theory with dispersion correction. (DFT-D, Density Functional Theory-Dispersive), with calculation level wB97X-D / cc-pVDZ, it was possible to develop a topological and energetic study to analyze the similarities and differences in crystallization mechanisms through intermolecular interactions.