Synthesis of some novel pyrazolo[3,4-d]pyrimidine derivatives as potential antimicrobial agents

Preparation and chemistry of 3/5-halogenopyrazoles.

3.01 – Pyrazoles

A series of novel pyrazole oxime derivatives containing a 2-chloro-5-thiazolyl moiety were synthesized. Their structures were confirmed by (1)H NMR, (13)C NMR, and elemental analysis. The preliminary bioassays showed that all of the title compounds had low acaricidal activity against Tetranychus cinnabarinus . However, most of them exhibited excellent insecticidal activity against Aphis medicagini at the dosage of 0.5 mg/mL, and some compounds still showed good insecticidal activity against A. medicagini even at the dosage of 0.2 mg/mL. Meanwhile, some title compounds displayed fungicidal and plant growth regulatory activities.

Synthesis and Biological Activities of Novel Pyrazole Oxime Derivatives Containing a 2-Chloro-5-thiazolyl Moiety

2,4-Dihydropyrazole glucosides 3a-3c were prepared and tested for theirantitumor activity. The structures of these compounds were established by 1H and 13C-NMR spectroscopy. Glucoside 3b shows an in vitro IC50 value of 16.4 μM againstproliferation of the human promyelotic leukemia (HL60) cell line.

https://www.mdpi.org/molecules/papers/90200109.pdf

Synthesis and Antitumor Activity of 5-Trifluoromethyl-2,4- dihydropyrazol-3-one Nucleosides

Synthesis and 13C NMR of (trifluoromethyl)hydroxypyrazoles

Reaction of ethyl 4,4,4-trifluoroacetoacetate with methylhydrazine produced not only the previously reported 5-hydroxy-3-(trifluoromethyl)pyrazole 1 but also its unknown isomer the 3-hydroxy-5-(trifluoromethyl)pyrazole 4. The structure assignements are etablished based on 13 C NMR spectra. Compound 1 was converted to 5-chloro-3-(trifluoromethyl)pyrazolecarboxylic acid 3 in two steps.

Ronald W. Schneider

Papers

Synthesis and 13C NMR of (trifluoromethyl)hydroxypyrazoles

Synthesis and 13C NMR of (Trifluoromethyl)hydroxypyrazoles.