288-94-8Relevant articles and documents
Mild and Catalyst-Free Microwave-Assisted Synthesis of 4,6-Disubstituted 2-Methylthiopyrimidines - Exploiting Tetrazole as an Efficient Leaving Group
Thomann, Andreas,Eberhard, Jens,Allegretta, Giuseppe,Empting, Martin,Hartmann, Rolf W.
, p. 2606 - 2610 (2015)
Typically, 4,6-disubstituted 2-thiomethylpyrimidines are synthesized starting from 4,6-dichloro-2-thiomethylpyrimidine or an amino-substituted precursor. However, these reactions take several hours up to days and require multiple steps. Herein, we report a novel, easy, and quick-to-prepare synthetic intermediate, namely 2-(methylthio)-4,6-di(1H-tetrazol-1-yl)pyrimidine, for the synthesis of these interesting target compounds. The intermediate can be transformed within minutes into desired substituted pyrimidines under mild conditions with moderate to excellent yields. The reaction can be conducted in an automated microwave system, at room temperature or by conventional heating. Furthermore, we demonstrate the robustness of the method in a one-pot procedure.
Evidence of Ligand Elasticity Occurring in Temperature-, Light-, and Pressure-Induced Spin Crossover in 1D Coordination Polymers [Fe(3ditz)3]X2 (X = ClO4–, BF4–)
Weselski, Marek,Ksi??ek, Maria,Kusz, Joachim,Bia?ońska, Agata,Paliwoda, Damian,Hanfland, Michael,Rudolf, Miko?aj F.,Ciunik, Zbigniew,Bronisz, Robert
, p. 1171 - 1179 (2017)
The complexes [M(3ditz)3]X2 [X = ClO4–, M = FeII (1), ZnII (2); X = BF4–, M = FeII (3), ZnII (4); 3ditz = 1,3-di(tetrazol-1-yl)propane] were prepared. Disordering of the propylene chain in 3ditz is not affected by thermally induced spin crossover in 1 (T1/2↓ = 149 K, T1/2↑ = 150 K) and 3 (T1/2↓ = 158, T1/2↑ = 161 K). Low-spin to high-spin (LS→HS) switching triggered by laser-light irradiation (520 nm) also does not influence the disordering of the ligand, leading to restoration of the initial HS phase. Pressurization of crystals results in a reduction of the Fe–N distances by about 0.19 ?, which indicates practically complete spin crossover (SCO). Also, in this case, the disordering of the ligand remains unchanged, although thermally and pressure-induced SCO is accompanied by different changes of 3ditz molecules. Upon thermally induced SCO, perturbation resulting from the reduction of the Fe–N distances is accompanied by a slight elongation of the bridging ligand. In contrast, in the range 0.25–0.55 GPa, the pressure-induced SCO is associated with shrinkage of the 3ditz molecule. Further elevation of pressure results in the inversion of structural changes and – similar to temperature-induced spin crossover – a slight elongation of the ligand molecule takes place.
SNAr azidation of phenolic functions utilizing diphenyl phosphorazidate
Ishihara, Kotaro,Shioiri, Takayuki,Matsugi, Masato
supporting information, (2019/12/27)
A useful method for the synthesis of aryl azides via SNAr reaction of phenol derivatives using diphenyl phosphorazidate (DPPA) as an azidation reagent was developed. Various phenol derivatives bearing electron-withdrawing groups were converted into the corresponding aryl azides in a single step. This method is easy to perform and enables the preparation of aryl azides without the use of explosive azide sources.
Microwave alkylation of lithium tetrazolate
Müller, Danny,Knoll, Christian,Weinberger, Peter
, p. 131 - 137 (2017/01/17)
Abstract: N1-substituted tetrazoles are interesting ligands in transition metal coordination chemistry, especially in the field of spin crossover. Their synthesis is performed in most cases according to the Franke-synthesis, using a primary amine as reagent introducing the substitution pattern. To enhance flexibility in means of substrate scope, we developed a new protocol based on alkylation of lithium tetrazolate with alkyl bromides. The N1–N2 isomerism of the tetrazole during the alkylation was successfully suppressed by use of highly pure lithium tetrazolate and 30?vol.% aqueous ethanol as solvent, leading to pure N1-substituted products. The feasibility of this reaction was demonstrated by a selection of different substrates. Graphical abstract: [Figure not available: see fulltext.]
