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The synthesis of 4,4′-arylmethylene-bis(3-(trifluoromethyl)-1-phenyl-1 H -pyrazol-5-ol) was performed effectively in aqueous media without catalyst by the reaction of aryl aldehydes and 1-phenyl-3-trifluoromethylpyrazol-5-one. All of the compounds obtained were characterized by elemental analysis, FTIR and 1 H NMR. The structure of compound 3g was further confirmed by the X-ray single crystal diffraction. The method has the advantages of mild condition, without any catalyst, high yields and environmentally benign procedure.

In this paper, both 1,4-dihydropyridinones (Hantzsch products) and 3,4-dihydropyrimidinones (Biginelli products) are synthesized in one-pot of aldehydes, β-dicarbonyl compounds and urea, catalyzing by non-toxic room temperature ionic liquid 1-n-butyl-3-methylimidazolium saccharinate (BMImSac). The ionic liquid (BMImSac) is environmentally benign associated with ionic liquid with F−. In order to improve the yield and selectivity, the effects of the mole proportion of reactants and solvents are investigated. Interestingly, by increasing the amount of ethyl acetoacetate or utilizing water as solvent, an unexpected by-product, Hantzsch product which is distinct from Biginelli product, is generated. All Biginelli and Hantzsch products are simultaneously purified and characterized by IR, 1H NMR and 13C NMR, of which one Biginelli product (4h) and one Hantzsch product (5b) are structurally determinated by X-ray single crystal diffraction. The crystal data for 4h: triclinic system, P-1 space group, a = 7.515(3) A, b = 9.011(4) A, c = 11.218(5) A, α = 106.288(6)°, β = 104.644(6)°, γ = 100.234(6)°, Z = 2, V = 679.7(5) A3, Dc = 1.36 g/cm3, R1 = 0.0603. The crystal data for 5b: monoclinic system, P2(1)/c space group, a = 9.765(3) A, b = 7.391(2) A, c = 24.795(7) A, β = 93.669(5)°, Z = 4, V = 1785.7(9) A3, Dc = 1.292 g/cm3, R1 = 0.0440.

Ethyl 5-amino-3-trifluoromethyl-1H-pyrazole-4-carboxylate (1) was efficiently synthesized via the condensation of ethyl cyanoacetate and trifluoroacetic anhydride, followed by chloridization and the condensation with aqueous hydrazine. Its unique reactivity was exploited for the synthesis of trifluoromethylated pyrazolo[1,5-a]pyrimidine (5) and pyrazolo[5,1-d][1,2,3,5]tetrazine-4(3H)-ones (8a–j). Among them, 5 was firstly found to be a novel fluorescent molecule that might be exploited as an attractive fluorophore for possessing many binding sites, and its fluorescence intensity was obviously stronger than its methyl analogue. 8 were found to be a new chemical class of potential monocotyledonous Echinochloa crus-galli L. Beauv inhibitors, and were more active than their methyl analogues.

A series of fourteen O-ethyl O-phenyl N-isopropyl phosphoroamidothioate enantiomers containing a phosphorus atom as a chiral center have been separated by high-performance liquid chromatography on a Pirkle model chiral stationary phase. Chromatography data, the capacity factor (k′) and the separation factor (α) of all solutes are presented. The influence of chromatographic conditions was investigated. The probable mechanism for chiral recognition is proposed.