Synthesis, Acid–Base Properties, and Sulfonylation of Dialkyl 5-Amino-2-hydroxy-4,6-dimethylisophtalates

Dialkyl 5-amino-2-hydroxy-4,6-dimethylisophthalates were synthesized for the first time by the reduction of the corresponding nitroso derivatives with sodium dithionite. The pKa and pKBH+ values of the synthesized compounds were determined and taken into account to find conditions for their sulfonylation with p-toluenesulfonyl chloride and p-acetamidobenzenesulfonyl chloride. As a result, previously unknown sulfonylated derivatives of substituted aminoisophthalates with potential antimicrobial properties were obtained. The composition and structure of the products were confirmed by IR, UV, and 1H NMR spectroscopy and mass spectrometry. The geometric structure of the sulfonylated compounds was established by DFT calculations at the BP86-D3/def2-SVP level of theory. The antibacterial effect of 5-(4-acetamidobenzenesulfonamido)-2-hydroxy-4,6-dimethylisophthalate was revealed.