Search results for "typpiyhdisteet"
showing 8 items of 18 documents
Retro Diels Alder protocol for regioselective synthesis of novel [1,2,4]triazolo[4,3-a]pyrimidin-7(1H)-ones
2020
Reactions of diastereochemically varied norbornene-condensed 2-thioxopyrimidin-4-ones6and10with variously functionalized hydrazonoyl chlorides2a-hgave regioselectively angular norbornene-based [1,2,4]triazolo[4,3-a]pyrimidin-7(1H)-ones7a-hand11a,c-e, respectively. Thermal retro Diels-Alder (RDA) reaction of7a-hand11a,c-eresulted in the target compounds4a-has single products. On the other hand, reactions of thiouracil1and hydrozonoyl chlorides2a-egave regioselectively [1,2,4]triazolo[4,3-a]pyrimidinone-5(1H)-ones3a-e. The opposite regioselectivity of thiouracil1and norbornene-condensed 2-thioxopyrimidin-4-ones6and10was attributed to electronic factors according to DFT calculations. The angul…
Synthesis and biological evaluation of the new ring system benzo[f]pyrimido[1,2-d][1,2,3]triazolo[1,5-a][1,4]diazepine and its cycloalkane and cycloa…
2021
Derivatives of the new ring system benzo[f]pyrimido[1,2-d][1,2,3]triazolo[1,5-a][1,4]diazepinone and its cycloalkane and cycloalkene condensed analogues have been conveniently synthesized through a three-step reaction sequence. An atom-economical, one-pot, three-step cascade process engaging five reactive centers (amide, amine, carbonyl, azide, and alkyne) has been performed for the synthesis of alicyclic derivatives of quinazolinotriazolobenzodiazepine using cyclohexane, cyclohexene, and norbornene β-amino amides. The stereochemistry and relative configurations of the synthesized compounds were determined by 1D and 2D NMR spectroscopy and X-ray crystallography. The reaction was also perfor…
Synthesis of N‐Monosubstituted Sulfondiimines by Metal‐free Iminations of Sulfiliminium Salts
2023
Sulfondiimines are marginalized entities among nitrogencontaining organosulfur compounds, despite offering promising properties for applications in various fields including medicinal and agrochemical. Herein, we present a metal-free and rapid synthetic procedure for the synthesis of N-monosubstituted sulfondiimines that overcomes current limitations in their synthetic accessibility. Particularly, S,S-dialkyl substrates, which are commonly difficult to convert by existing methods, react well with a combination of iodine, 1,8-diazabicyclo[5.4.0]undec-7-en (DBU), and iminoiodanes (PhINR) in acetonitrile (MeCN) to furnish the corresponding sulfondiimines in yields up to 85% (25 examples). Valua…
N-(2,3,5,6-Tetrafluoropyridyl)sulfoximines : synthesis, X-ray crystallography, and halogen bonding
2020
In the presence of KOH, NH-sulfoximines react with pentafluoropyridine to give N-(tetrafluoropyridyl)sulfoximines (NTFP-sulfoximines) in moderate to excellent yields. Either a solution-based or a superior solvent-free mechanochemical protocol can be followed. X-Ray diffraction analyses of 26 products provided insight into the bond parameters and conformational rigidity of the molecular scaffold. In solid-state structures, sulfoximines with halo substituents on the S-bound arene are intermolecularly linked by C–X⋯O[double bond, length as m-dash]S (X = Cl, Br) halogen bonds. Hirshfeld surface analysis is used to assess the type of non-covalent contacts present in molecules. For mixtures of th…
Removal of ammonium ions from aqueous solutions using alkali-activated analcime as sorbent
2023
Five alkali-activated analcime (ANA) sorbents (ANA-MK 1, ANA 2, ANA 3, ANA-MK 4, and ANA-MK 5) were developed for ammonium (NH4+) ion removal. Acid treatment and calcination were used as pre-treatments for analcime, and metakaolin (MK) was used as a blending agent in three sorbents. Sorption experiments were performed to evaluate the effects of sorbent dosage (1–20 g L−1), initial NH4+ ion concentration (5–1000 g L−1), and contact time (1 min–24 h). ANA-MK 1, ANA 2, and ANA-MK 4 were the most efficient sorbents for NH4+ ion removal, with a maximum experimental sorption uptake of 29.79, 26.00, and 22.24 mg g−1, respectively. ANA 3 and ANA-MK 5 demonstrated…
Transition path selection between ammonium nitrate solid phases IV, III and II
1994
Article dissertation. Contains an introduction and five articles. This study was made of factors affecting the transition paths between ammonium nitrate solid state phases IV, III and II. The effect of the sample preparation method was investigated by differential scanning calorimetry (DSC), transition mechanisms were explored with simultaneous DSC and Raman spectrometry developed for in situ investigation of the transitions, and the relationship between phase IV structure and the transition paths was studies by X-ray powder diffraction (XRD) and DSC. The results were analysed by partial least-squares regression (PLS) and principal component analysis (PCA). [Continues; please see the book]