2036-41-1Relevant articles and documents
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 - 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)
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.
