70733-12-9Relevant articles and documents
Toward Continuous-Flow Synthesis of Biologically Interesting Pyrazole Derivatives
Das, Amrita,Ishitani, Haruro,Kobayashi, Shū
supporting information, p. 5127 - 5132 (2019/11/13)
A two-step continuous-flow synthesis of substituted pyrazole derivatives has been developed via the formation of vinylidene keto esters as key intermediates. Heterogeneous Ni2+-montmorillonite was found to be an efficient catalyst for orthoester condensation of 1,3-dicarbonyls under flow conditions. The intermediate reacted with methylhydrazine to afford pyrazole derivatives, for which suitable selection of a solvent played a key role in achieving high yields and excellent regioselectivities of the desired products. An application of this protocol has been demonstrated by the synthesis of a key intermediate for biologically active pyrazoles such as Bixafen. (Figure presented.).
Iron Catalysis for Modular Pyrimidine Synthesis through β-Ammoniation/Cyclization of Saturated Carbonyl Compounds with Amidines
Chu, Xue-Qiang,Cao, Wen-Bin,Xu, Xiao-Ping,Ji, Shun-Jun
, p. 1145 - 1154 (2018/06/18)
An efficient method for the modular synthesis of various pyrimidine derivatives by means of the reactions of ketones, aldehydes, or esters with amidines in the presence of an in situ prepared recyclable iron(II)-complex was developed. This operationally simple reaction proceeded with broad functional group tolerance in a regioselective manner via a remarkable unactivated β-C-H bond functionalization. Control experiments were performed to gain deep understanding of the mechanism, and the reactions are likely to proceed through a designed TEMPO complexation/enamine addition/transient α-occupation/β-TEMPO elimination/cyclization sequence.
Copper-Catalyzed One-pot Synthesis of Pyrimidines from Amides, N,N′-dimethylformamide dimethylacetal, and Enamines
Jalani, Hitesh B.,Cai, Wangshui,Lu, Hongjian
supporting information, p. 2509 - 2513 (2017/07/22)
A versatile copper catalyzed one-pot synthesis of diversely substituted pyrimidines directly from amides, N,N′-dimethylformamide dimethylacetal (DMF?DMA) and enamines has been established. The reaction involved the two C?N bonds and one C?C bond formation by formal [2+1+3] annulation approach to pyrimidines. This protocol is based on the use of readily available primary amides, DMF?DMA and enamines to install di- and tri-substituted pyrimidine structure with diverse functionality in one-pot manner, which makes this strategy to be appealing for the medicinal chemistry. (Figure presented.).
Characterization of amide bond conformers for a novel heterocyclic template of N-acylhydrazone derivatives
Lopes, Alexandra Basilio,Miguez, Eduardo,Kuemmerle, Arthur Eugen,Rumjanek, Victor Marcos,Fraga, Carlos Alberto Manssour,Barreiro, Eliezer J.
, p. 11683 - 11704 (2013/11/06)
Herein we describe NMR experiments and structural modifications of 4-methyl-2-phenylpyrimidine-N-acylhydrazone compounds (aryl-NAH) in order to discover if duplication of some signals in their 1H- and 13C-NMR spectra was related to a mixture of imine double bond stereoisomers (E/Z) or CO-NH bond conformers (syn and anti-periplanar). NMR data from NOEdiff, 2D-NOESY and 1H-NMR spectra at different temperatures, and also the synthesis of isopropylidene hydrazone revealed the nature of duplicated signals of a 4-methyl-2-phenylpyrimidine-N-acylhydrazone derivative as a mixture of two conformers in solution. Further we investigated the stereoelectronic influence of substituents at the ortho position on the pyrimidine ring with respect to the carbonyl group, as well as the electronic effects of pyrimidine by changing it to phenyl. The conformer equilibrium was attributed to the decoplanarization of the aromatic ring and carbonyl group (generated by an ortho-alkyl group) and/or the electron withdrawing character of the pyrimidine ring. Both effects increased the rotational barrier of the C-N amide bond, as verified by the ΔG≠ values calculated from dynamic NMR. As far as we know, it is the first description of aryl-NAH compounds presenting two CO-NH bond-related conformations.
Biaryl substituted alkylboronate esters as thrombin inhibitors
Quan,Wityak,Dominguez,Duncia,Kettner,Ellis,Liauw,Park,Santella,Knabb,Thoolen,Weber,Wexler
, p. 1595 - 1600 (2007/10/03)
Thrombin is a serine protease that plays an important role in the blood coagulation cascade, and is a target enzyme for new therapeutic agents. Ac- (D)-Phe-Pro-boroArg-OH (DuP 714) was found to be a highly effective thrombin inhibitor. In order to reduce the peptidic nature of DuP 714, we have designed a series of novel biaryl substituted alkylboronate esters as potent thrombin inhibitors. The most potent compounds have subnanomolar affinity for thrombin.
Studies on cerebral protective agents. I. Novel 4-arylpyrimidine derivatives with anti-anoxic and anti-lipid peroxidation activities
Kuno,Sugiyama,Katsuta,Kamitani,Takasugi
, p. 1452 - 1461 (2007/10/02)
Novel 4-arylpyrimidine derivatives were synthesized by the oxidation of 4-aryl-1,4-dihydropyrimidines, and their effects on anti-anoxic (AA) activity in mice and anti-lipid peroxidation (ALP) activity in rat brain mitochondria were investigated. Among these compounds, ethyl 6-methyl-2-phenyl-4-(4-pyridyl)-5-pyrimidinecarboxylate (4b) has AA activity (10mg/kg, i.p.) and ethyl 6-methyl-4-(3-nitrophenyl)-2-phenyl-5-pyrimidinecarboxylate (4f) has ALP activity (73% inhibition at 10-5 g/ml). The latter compound (100mg/kg, i.p.) was also effective on arachidonate-induced cerebral edema in rats with comparable potency to that of vitamin E.
Reaction of 2-Dimethylaminomethylene-1,3-diones with Dinucleophiles. VIII. Synthesis of Ethyl and Methyl 2,4-Disubstituted 5-Pyrimidinecarboxylates
Schenone, Pietro,Sansebastiano, Laura,Mosti, Luisa
, p. 295 - 305 (2007/10/02)
Reaction of ethyl or methyl 2-dimethylaminomethylene-3-oxoalkanoates with N-C-N dinucleophiles such as guanidine, acetamidine or benzamidine afforded in high yields the relative esters of 4-substituted 2-amino-, 2-methyl- or 2-phenyl-5-pyrimidinecarboxylic acids, respectively.These esters were hydrolyzed to the corresponding carboxylic acids, which were converted by heating to 4-substituted 2-pyrimidinamines, 2-methyl or 2-phenylpyrimidines, respectively, generally in excellent yields.The 4-unsubstituted ethyl 2-amino-, 2-methyl- and 2-phenyl-5-pyrimidinecarboxylateswere obtained in moderate yields by reaction of the above dinucleophiles with ethyl 2,2-diformylacetate.These esters were hydrolyzed and the corresponding acids (with the exception of the 2-methyl derivative) were decarboxylated to give 2-pyrimidinamine and 2-phenylpyrimidine in satisfactory yields.
