2036-41-1Relevant academic research and scientific papers
Palladium-Catalyzed Methylation of Aryl, Heteroaryl, and Vinyl Boronate Esters
Haydl, Alexander M.,Hartwig, John F.
supporting information, p. 1337 - 1341 (2019/02/26)
A method for the direct methylation of aryl, heteroaryl, and vinyl boronate esters is reported, involving the reaction of iodomethane with aryl-, heteroaryl-, and vinylboronate esters catalyzed by palladium and PtBu2Me. This transformation occurs with a remarkably broad scope and is suitable for late-stage derivatization of biologically active compounds via the boronate esters. The unique capabilities of this method are demonstrated by combining carbon-boron bond-forming reactions with palladium-catalyzed methylation in a tandem transformation.
A N - 2 - pyridyl -5 - pyrimidine preparation of method (by machine translation)
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Paragraph 0016; 0018; 0021; 0023; 0026; 0028, (2019/01/08)
The invention relates to a pesticide in the technical field, and discloses a N - 2 - pyridyl - 5 - pyrimidine preparation of method, comprises the following steps: the 3 - ethoxy - 2 - methyl acrolein with ammonia ammoniation reaction to produce 3 - amino - 2 - methacrolein, the quality of the ammonia concentration is 20 - 25%, the 3 - ethoxy - 2 - methyl acrolein and ammonia in a molar ratio of 1: 1.0 - 1.5: 1.0 - 6.0. The N - 2 - pyridyl - 5 - pyrimidine preparation of method, by 3 - ethoxy - 2 - methyl acrolein as the starting material, through the ammoniation, cyclizes and brominated to obtain 5 - bromo methyl pyrimidine, then with 2 - aminopyridine reaction to obtain the target product, this invention adopts the cheap and easy to obtain 3 - ethoxy acrolein, in conventional process compared with the use of expensive 5 - pyrimidine formaldehyde, and greatly reduces the production cost, at the same time the invention the preparation method has the advantage of high yield, low cost, high efficiency in the production of more, in low-cost cases can prepare more N - 2 - pyridyl - 5 - pyrimidine methylamine, high practicability. (by machine translation)
A N - 2 - pyridine -5 - pyrimidine preparation of method (by machine translation)
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Paragraph 0033; 0039, (2018/09/11)
The invention belongs to the technical field of agricultural chemical intermediates, in particular to a N - 2 - pyridine - 5 - pyrimidine preparation of method. The preparation method is to cheap and easily obtained 3 - ethoxy - 2 - methyl acrolein as the starting material, with 25% ammonia reaction, to obtain 3 - amino - 2 - methyl acrolein; then with the formamide cyclized, to obtain 5 - methyl pyrimidine; in a carbon tetrachloride solution N - bromo succinimide bromide to obtain 5 - bromo methyl pyrimidine; then under the action of the triethylamine, with 2 - aminopyridine reaction to obtain N - 2 - pyridine - 5 - pyrimidine methylamine. The invention realized through designing a brand new N - 2 - pyridine - 5 pyrimidine methylamine preparation process route, in order to 3 - ethoxy - 2 - methyl acrolein as the starting material, through the ammoniation, cyclization, to obtain the bromide 5 - bromo methyl pyrimidine, then with 2 - aminopyridine reaction to obtain the target product; this invention adopts the cheap and easy to obtain 3 - ethoxy acrolein, in conventional process compared with the use of expensive 5 - pyrimidine formaldehyde, and greatly reduces the production cost. (by machine translation)
METHOD FOR RAPIDLY METHYLATING HETEROAROMATIC ARENE AND METHOD FOR PRODUCING TRACER FOR USE IN PET
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Page/Page column 5-6, (2011/11/06)
Provided is a method whereby a heteroaromatic ring aryl can be very rapidly methylated at a high yield. In an N-alkyl-2-pyrrolidinone, a heteroaromatic ring aryltrialkylstannan is cross-coupled with methyl iodide in the presence of a palladium complex, a phosphine ligand, a cuprous halide, a carbonic acid salt and/or an alkali metal fluoride to thereby rapidly methylate the heteroaromatic ring aryl. (Formula shows a case wherein the heteroaromatic ring aryl is a pyridyl group.)
Pd0-mediated rapid coupling between methyl iodide and heteroarylstannanes: an efficient and general method for the incorporation of a positron-emitting11C radionuclide into heteroaromatic frameworks
Suzuki, Masaaki,Sumi, Kengo,Koyama, Hiroko,Siqin,Hosoya, Takamitsu,Takashima-Hirano, Misato,Doi, Hisashi
experimental part, p. 12489 - 12495 (2010/06/11)
The Pd0-mediated rapid trapping of methyl iodide with an excess amount of a heteroaryl-substituted tributylstannane has been investigated with the aim of incorporating a shortlived 11C-labelled methyl group into the heteroaromatic carbon frameworks of important organic compounds, such as drugs with various heteroaromatic structures, in order to execute a positron emission tomography (PET) study of vital systems. The reaction was first performed by using our previously developed CH3I/stannane/[Pd 2(dba)3]/ P(o-CH3C6H 4)3/CuCl/K2CO3 (1:40:0.5:2:2:2) system in DMF at 60°C for 5 min (conditions A), however, the reaction gave low yields for various heteroaromatic compounds. Increasing the amount of phosphine ligand (condi tions B) led to a significant improvement in the yield, but the conditions were still not suitable for a range of basic heteroaromatic structures. Use of the CuBr/CsF system (conditions C) also provided a result similar to that obtained under conditions B with an increased amount of the phosphine. Thus, pyridine and related heteroaromatic compounds remained less reactive substrates. The problem was overcome by replacing the DMF solvent with N-methyl-2-pyrolidinone (NMP). The reaction in NMP at 60-100°C for 5 min using a CH3I/stannane/[Pd2-(dba)3]/P(o-CH 3C6H4)3/CuBr/CsF (1:40:0.5:16:2:5) combination (conditions D) gave the methylated products in yields of more than 80% (based on the reaction of CH3I) for all of the heteroaromatic compounds listed in this study. Thus, the combined use of NMP and an increased amount of phosphine is important for promoting the reaction efficiently. The use of this general approach to rapid methylation has been well demonstrated by the synthesis of the PET tracers 2- and 3-[11C]methylpyridines by using [Pd2(dba)3]/P(o-CH3C6H 4)3/CuBr/CsF (1:16:2:5) in NMP at 60°C for 5 min, which gives the desired products in HPLC analytical yields of 88 and 91%, respectively.
Palladium catalyzed cross-methylation of bromoheterocycles with intramolecularly stabilized dimethyl indium reagents
Jaber, Nimer,Schumann, Herbert,Blum, Jochanan
, p. 565 - 567 (2007/10/03)
Although the intramolecularly stabilized [(3- dimethylamino)propyl]dimethylaluminum (1a) fails to undergo palladium-catalyzed cross-coupling with bromopyridines and with bromofuran derivatives, the analogous gallium and indium reagent lb and 1c smoothly c
An N.M.R. Study of Electron Donor-Electron Acceptor Interaction Between Aromatic Hydrocarbons and Diazines
Hurst, Derek T.,Thakrar, Usha B.,Wells, Clifford H. J.,Wyer, John
, p. 1313 - 1319 (2007/10/02)
Equilibrium constants have been measured by n.m.r. spectroscopy for the electron donor-electron acceptor interaction between a number of aromatic hydrocarbons and diazines.The values obtained have shown that the interaction is weak, and that the aromatic hydrocarbon acts as the electron donor and the diazine as the electron acceptor in the systems studied.Chemical-shift data have provided evidence for the relative positioning of the donor and acceptor components within the various complexes.The effect of temperature on the equilibrium constant for complex formation between (2H6)benzene and pyrazine has shown that the enthalpy of format ion is close to zero.
