Two new pyrrolo[2,3-d]pyrimidines (7-deazapurines): ultrasonic-assisted synthesis, experimental and theoretical characterizations as well as antibacterial evaluation

Abstract

Two new pyrrolo[2,3-d] pyrimidines (7-deazapurines) were synthesized in high yields by the reaction of 2-amino-1-methyl-4,5-diphenyl-1H-pyrrole-3-carbonitrile with triethyl orthoformate followed by cyclocondensation with methyl or benzyl amine in refluxing glacial acetic acid or using ultrasonic irradiation containing a catalytic amount of glacial acetic acid at 60 degrees C. For each product, the correct structural isomer was identified using the FT-IR, H-1 NMR, C-13 NMR, 2D nuclear Overhauser effect spectroscopy spectral and microanalytical data together with comparison of the experimental and calculated chemical shifts at the B3LYP/6-31+G(d, p) level of theory. Furthermore, the synthesized compounds were evaluated for their antibacterial activity against Gram-positive bacteria (Staphylococcus aureus and Micrococcus luteus) and Gram- negative bacteria (Escherichia coli) by the agar dilution method using 24- well microtiter plates.