- Pot-economic synthesis of diarylpyrazoles and pyrimidines involving Pd-catalyzed cross-coupling of 3-trifloxychromone and triarylbismuth
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Abstract: The present study reveals the formation of 3,4-diarylpyrazole and 4,5-diarylpyrimidine in one-pot operation starting from 3-trifloxychromone and triarylbismuth. The complete process encompasses two steps in the one-pot operation. The first step leads to the formation of isoflavone via cross-coupling reaction of 3-trifloxychromone and triarylbismuth as a threefold arylating reagent. These isoflavones were further converted into 3,4-diarylpyrazole and 4,5-diarylpyrimidine using hydrazine hydrate and guanidinium chloride in the successive step in the same pot. Interestingly the formation of 3,4-diarylpyrazole was achieved in the shortest reaction time i.e., 30 min that too at room temperature. Overall the developed methodology provides easy access to the medicinally important diarylpyrazole and pyrimidine moiety in one-pot operation and in short reaction time. Graphical Abstract: Synopsis The work presented here describes the novel methodology for the formation of medicinally important heterocycles 3,4-diarylpyrazole and 4,5-diarylpyrimidine in one-pot operation starting from 3-trifloxychromone and triarylbismuth.
- Kumar, Abhijeet,Rao, Maddali L N
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- Reactions of 2Н(4Н)-chromenes with dinucleophiles: one-step synthesis of 2-(1H-(bi)pyrazol-3-yl)- and 2-(1,4(5)-(benzo)diazepin-4-yl)phenols
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[Figure not available: see fulltext.] Novel derivatives of 2-(1H-(bi)pyrazol-3-yl)phenols and 2-(1,4(5)-(benzo)diazepin-4-yl)phenols were obtained in the reaction of (4-amino-2H-chromen-2-ylidene)malondialdehyde and 4H-chromen-4-imines with 1,2-, 1,3-, and 1,4-dinucleophiles proceeding as a cascade reaction initiated by the Michael reaction.
- Zahorulko, Serhii P.,Varenichenko, Svetlana А.,Farat, Oleg K.,Mazepa, Aleksander V.,Okovytyy, Sergiy I.,Markov, Victor I.
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p. 859 - 867
(2018/11/10)
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- Synthesis, crystal structure, characterization and antifungal activity of 3,4-diaryl-1H-Pyrazoles derivatives
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A series of 3,4-diaryl-1H-pyrazoles derivatives were designed and synthesized by the reaction of 3-heteroarylchromones and 3-phenylchromones with hydrazine hydrate in good yields. All of those compounds were characterized by 1H NMR, 13C NMR, IR, and HRMS. Moreover, 3-(2,4-dihydroxyphenyl)-4-(4-hydroxyphenyl)-1H-pyrazole and 3-(2,4-dihydroxy phenyl)-4-(4-methoxyphenyl)-1H-pyrazole were further conformed by the single crystal X-ray diffraction. In addition, the antifungal activity against five phytopathogenic fungi (Cytospora sp., Colletotrichum gloeosporioides, Botrytis cinerea, Alternaria solani and Fusarium solani) of 3,4-diaryl-1H-pyrazoles were evaluated. 3-(2-Hydroxy-4-isopropoxyphenyl)-4-phenyl-1H-pyrazole was more better and broader inhibitory effect on Cytospora sp., C. gloeosporioides, A. solani and Fusarium solani with IC50 values of 26.96, 28.84, 16.77 and 22.10 μg/mL, respectively. 4-(4-Fluorophenyl)-3-(2-hydroxy-4-methoxyphenyl)-1H-pyrazole exhibited fairly effective antifungal activity against Cytospora sp., C. gloeosporioides and A. solani with IC50 values of 11.91, 14.92 and 16.98 μg/mL, respectively.
- Zhang, Jin,Tan, Da-Jin,Wang, Tao,Jing, Si-Si,Kang, Yang,Zhang, Zun-Ting
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p. 235 - 242
(2017/08/09)
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