Aim and Objective:
A novel collection of fused pyrimidine, pyridine, pyrazole, chromene and thiophene
derivatives 2-30 have been newly synthesized by using the 1a, b as starting material. Fused pyrane exhibits
a range of pharmacological activity such as cancer agents [1], antimicrobial [2-4], antioxidant [5], antiproliferative
[6], cytotoxic activity [7], anticipated antitumor [8], antiparkinsonian [9] and anti-inflammatory [10].
Moreover, pyrane derivatives are well known for bacterial biofilm disruptor [11], anticonvulsant [12] and inhibitors
of mycobacterium bovis [13].
Materials and Methods:
All melting points were measured using the Akofler Block instrument and are uncorrected.
IR spectra (KBr) were recorded on a FTIR 5300 spectrometer (υ, cm-1). The 1H-NMR spectra were recorded
on a Varian Gemini spectrometer. The 1H-NMR spectra were run at 300, 400 MHz and 13C-NMR spectra
were run at 100 MHz in DMSO-d6, CDCl3 as solvents. The chemical shifts are expressed in parts per million
(ppm) by using tetramethylsilane (TMS) as an internal reference, 1000 EX mass spectrometer at 70 eV. The purity
of synthesized compounds was checked by thin-layer chromatography (TLC) (aluminum sheets) using nhexane,
EtOAc (9:1, V/V, 7:3 V/V) eluent. Elemental analyses were carried out by the Microanalytical Research
Center, Faculty of Science, and Microanalytical Unit, Faculty of Pharmacy, Cairo University, Egypt.
Results and Discussion:
A novel series of azoles and azines were designed and prepared via the reaction of 7-amino-
5-(4-chlorophenyl)-4-phenyl-2-thioxo-2,5-dihydro-1H-pyrano- [2,3-d]pyrimidine-6-carbonitrile 1a and 7-amino-4,5-
diphenyl-2-thioxo-2,5-dihydro-1H-pyrano[2,3-d]-pyrimidine-6-carbonitrile 1b with some electrophilic and nucleophilic
reagents. The structures of target compounds were confirmed by elemental analyses and spectral data. The
novel synthesized compounds showed good antimicrobial activity against the previously mentioned microorganisms.
Conclusion:
In conclusion, compounds 1a, 1b underwent ready cyclization to give fused heterocyclic compounds
through reaction with different reagents and under different conditions and subjected to antimicrobial screening.
TMS is Superior to Residual CHCl3 for Use as the Internal Reference for Routine 1H NMR Spectra Recorded in CDCl3