- Normal Vibrations of 4-Methyl- and 4-Methyl-d3-pyridines
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Assignment of the normal vibrations of 4-methylpyridine was made through the vibrational analyses of the Raman and infrared spectra and also through the normal coordinate calculation.The assignment was confirmed by the study made on 4-methyl-d3-pyridine.
- Yoshikai, Kazumasa,Hieida, Toshikazu,Nibu, Yoshinori,Shimada, Hiroko,Shimada, Ryoichi
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- A facile and general acid-catalyzed deuteration at methyl groups of N-heteroarylmethanes
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A facile and general Br?nsted acid-catalyzed deuteration at the methyl group of N-heteroarylmethanes was achieved through a dearomatic enamine intermediate under relatively mild reaction conditions. Both 2-methyl and 4-methyl groups in quinolines were deuterated with high deuterium incorporation. Pyridines, benzo[d]thiazoles, indoles and imines including these clinical drugs were also deuterated efficiently at the methyl groups. This reaction could be conducted on a large scale (500 mmol), showing its good potential for use in large-scale synthesis.
- Liu, Min,Chen, Xue,Chen, Tieqiao,Yin, Shuang-Feng
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- Deuterated aza aromatic compound and synthesis method thereof
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The invention provides a synthetic method for preparing a deuterated aza aromatic compound, which has the advantages of simple reaction condition, high selectivity and high deuterated ratio. The method is carried out in an inert gas atmosphere or in an air atmosphere, and an acid reagent is used as one only catalyst for synthesis of the deuterated aza aromatic compound directly from an aza aromatic compound and a deuterated reagent. The method does not need the reaction conditions such as a ligand, microwave radiation, a high pressure, an organic reaction solvent and the like. The substrate is cheap, easily-available, and rich in the nature, does not need prefunctionalization, and has the advantages of wide adaptability and simple experiment operation. At the same time, the method has good chemical and regioselectivity, and can effectively realize the deuteration of the aza aromatic compound. The method has a very important application prospect in the organic synthesis and medicinal chemistry-related isotope labelling field.
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Paragraph 0070; 0071; 0072
(2017/08/28)
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- SITE SELECTIVE EFFECT OF N-OXIDE FUNCTION TO METHYL GROUPS ON SIX-MEMBERED N-HETEROAROMATICS
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Reaction of 2,4-dimethylpyridine 1-oxide with ethyl benzoate under basic conditions afforded 4-methyl-2-phenacylpyridine 1-oxide, while the same reaction of 2,4-dimethylpyridine itself is known to afford 2-methyl-4-phenacylpyridine.Concerning the above contrast, the effect of N-oxide function to the relative reactivity of the 2- and 4-methyl group was investigated on pyridine, quinoline, pyrimidine, and quinazoline homologues.The higher reactivity of α-methyl groups was concluded to be general in the N-oxides of these N-heteroaromatics.
- Sakamoto, Takao,Yoshizawa, Hiroshi,Yamanaka, Hiroshi,Goto, Yoshinobu,Niiya, Tokihiro,Honjo, Noriko
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