Haloacetylated enol ethers 10. Condensation of β-alkoxyvinyl trifluoromethyl ketones with thiosemicarbazide. Synthesis of new trifluoromethyl 4,5-dihydro-1H-1-pyrazolethiocarboxyamides

Preparation of α,β-unsaturated trifluoromethylketones and their application in the synthesis of heterocycles

“…107 They can be transformed into N-unsubstituted pyrazoles 288 in high yields using acidic hydrolysis. The ketone 289 has the hidden bromoketone fragment; it was applied for forming thiazole connected with pyrazoline 291.…”

Regiospecific synthesis of new fatty N-acyl trihalomethylated pyrazoline derivatives from fatty acid methyl esters (FAMEs)

“…12,13 In previous reports, which related the cyclocondensation reactions between 4-alkoxy-1,1,1-trihalo-3-alken-2-ones and no-fatty N-acyl hydrazines, e.g., semicarbazide or tiossemicarbazide, the pyrazoline derivatives were obtained under mild conditions, methanol refluxing, with good to excellent yields (71-96%). 21,22 Initially, to prepare fatty N-acyl trihalomethylated pyrazoline derivatives 10-15, the cyclocondensation reactions were performed from fatty N-acyl hydrazines 3a-c and enones 4-9 through mild conditions in refluxing methanol with a reaction time of 12 h. However, the presence of a strong electronwithdrawing substituent at the N1 of 1,2-dinucleophile makes it less reactive. This is because the electron pairs of nitrogen atoms are in resonance with the carbonyl group and demand more specific reaction conditions.…”

“…21,22,[25][26][27] Also, the presence of a trihalomethylated group at the vinyl ketone and the chain derived from the fatty acid at the dinucleophile were crucial for the regiochemistry of the reactions, which produced only the 5-trihalomethylated isomers. The suggested pathway to the cyclocondensation reaction is shown in Scheme 2.…”

Synthesis, Characterization and DFT Studies of 4-(2,4-Difluorobiphenyl-4-Yl)-6-Phenylpyrimidin-2-Amine

“…Especially 2-amino substituted pyrimidine has frequently been studied during the recent decades as they act as synthetic precursors in a variety of organic conversions and in coordination chemistry [9]. Moreover, many fluorinated scaffolds are known to exhibit a broad range of biological activities in medicinal and agricultural scientific fields [10]. Thus, fluorine substitution remains an attractive means in the development of more efficient and selective pharmaceutical drug molecules.…”