Microwave-Assisted Synthesis and Antimicrobial Evaluation of Novel Spiroisoquinoline and Spiropyrido[4,3-d]pyrimidine Derivatives

Abstract

Bromination of N-substituted homophthalimides and tetrahydropyrido[4,3-d]-pyrimidine-5,7-diones produces 4,4-dibromohomophthalimide and 8,8-dibromo-tetrahydropyrido[4,3-d]pyrimidine-5,7-dione derivatives, respectively, that can be used as precursors for spiro derivatives. The dibromo derivatives react with different binucleophilic reagents to produce several spiroisoquinoline and spirotetrahydropyrido[4,3-d]-pyrimidine-5,7-dione derivatives, respectively. Reaction of the dibromo derivatives with malononitrile produces dicyanomethylene derivatives which react with different binucleophiles to produce new spiro derivatives. All new compounds are prepared by using the usual chemical conditions and microwave assisted conditions. The latter conditions improved the reaction yields, reduced reaction times and ameliorated the effects on the surrounding environment as the reactions are carried out in closed systems. Structures of the newly synthesized compounds are proved using spectroscopic methods such as IR, MS, 1H-NMR and 13C-NMR and elemental analyses. Some of the newly synthesized compounds were tested for their antimicrobial activities, whereby four of them showed moderate activities and the rest showed low or no activities towards the investigated species.

Design, Synthesis and Antibacterial Evaluation of Some New 2-Phenyl-quinoline-4-carboxylic Acid Derivatives

“…The quinoline ring occurs in various natural products and represents a key motif in medicinal chemistry [9][10][11][12], and its derivatives, quinoline-4-carboxylic acids, are a group of compounds associated with different biological activities, such asantiviral [13], anti-inflammatory [14], antimicrobial [15], anti-atherothrombosis [16], antiemetic [17], anxiolytic [18], antimalarial and antileishmanial [19]. Although quinoline-4-carboxylic acid derivatives exhibit various bioactivities, the research of new quinoline-4-carboxylic acid-based antibacterial drugs has developed slowly.…”

Exploration of the Chemistry and Biological Properties of Pyrimidine as a Privilege Pharmacophore in Therapeutics

“…Pyrimidine has largest zones of inhibition against Aspergillus niger (10 mm) and Penicillium sp. (9 mm) among the compounds screened by Faty et al (2015). Benzothiazole-pyrimidine was the most active among those tested by Maddila et al (2013).…”

Synthesis of Some Substituted Pyrazolopyrimidine Derivatives: An Environmentally Benign Approach

“…Synthesis of N‐substituted heterocycles using microwave irradiation has attracted the interest of chemists worldwide because it is a highly efficient and time‐saving process. Environmentally benign synthesis of N‐heterocycles under microwave irradiation has been reported in literature . The use of ionic liquids in organic synthesis has further enhanced the efficiency of the entire process of synthesis, simply owing to their several advantages such as low melting point, high thermal stability , negligible vapor pressure , and high ionic conductivity .…”