Abstract
A microwave reactor was used to synthesize a series of novel 3,6-disubstituted or 3-substituted pyrazolo[1,5-a]pyrimidines in a total of 1 hour reaction time over 3 steps. The products were obtained in good to excellent yields (34-92%, ave = 52%) using a straightforward synthesis starting with the reaction of dimethylformamide-dimethylacetal with commercially available aryl acetonitriles (120C, 20 min). This was followed by treatment with H2NNH2 • HBr (120C, 20 min), and then reacted with either 1,1,3,3-tetramethoxypropane or a 2-aryl-substituted malondialdehydes (120C, 20 min). The resulting product was either collected on a sintered glass funnel or purified via column chromatography. The compounds were screened for anti-cancer activity against A2780 Ovarian and/or MCF7 breast cancer cell lines in vitro. The most active compounds were the 3-(4-(trifluoromethyl)phenyl)-6-[4-(2-(piperidin-1-yl)ethoxy]phenyl analogue and the 3-(2-fluorophenyl)-6-[4-(2-(4-methylpiperzin-1-yl)ethoxy]phenyl analogue, exhibiting EC50 values of 0.84 and 0.52 M respectively, which is 2-3 times more potent than Dorsomorphin. Several of the derivatives also showed promising activities against several viruses of emerging concern, including HBV, MERS Coronavirus, Zika, and Ebola. Use of a microwave reactor to synthesize N’-aryl/(alkyl) substituted N-[(4-hydroxy-6-phenyl)pyrimidin-2-yl]guanidines or N-[(4-hydroxy-6-trifluoromethyl)pyrimidin-2-yl]guanidines from the corresponding cyanamides with alkyl/aryl amines was achieved in good to excellent yields (39-96%, ave = 62%) in 10 minutes at 120C using only 1 equivalent of amine. Work-up was exceptionally simple, and involved collecting precipitated solids on a sintered glass funnel and washing with cold 2-propanol. Products were obtained in analytically pure form and required approximately 1 hour to prepare, start to finish. Compounds in this series showed early promise as potential inhibitors of A2780 Ovarian cancer, in vitro.
Degree
PhD
College and Department
Physical and Mathematical Sciences; Chemistry and Biochemistry
Rights
https://lib.byu.edu/about/copyright/
BYU ScholarsArchive Citation
Singleton, Justin Dave, "Synthesis and Biological Evaluation of Pyrazolo[1,5-a]pyrimidines and (4-Hydroxy-6-trifluoromethylpyrimidin-2-yl) guanidines" (2021). Theses and Dissertations. 9713.
https://scholarsarchive.byu.edu/etd/9713
Date Submitted
2021-08-02
Document Type
Dissertation
Handle
http://hdl.lib.byu.edu/1877/etd12544
Keywords
Microwave, Dorsomorphin, Pyrazolo[1, 5-a]pyrimidine, N-[(4-hydroxy-6-trifluoromethyl)pyrimidin-2-yl]guanidine, anticancer, antiviral
Language
english