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Methylation of 5‐Amino‐3‐methylthio‐1 H ‐pyrazole Derivatives and Two Related Crystal Structures
Author(s) -
Ren XueLing,
Wu Chao,
Hu FangZhong,
Zou XiaoMao,
Yang HuaZheng
Publication year - 2004
Publication title -
chinese journal of chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.28
H-Index - 41
eISSN - 1614-7065
pISSN - 1001-604X
DOI - 10.1002/cjoc.20040220218
Subject(s) - chemistry , pyrazole , substituent , ring (chemistry) , methylation , stereochemistry , crystal structure , medicinal chemistry , crystallography , organic chemistry , biochemistry , gene
5‐Amino‐3‐methylthio‐1 H ‐pyrazoles are very important building blocks from which a wide variety of pyrazole derivatives can be prepared. When substituted 5‐amino‐3‐methylthio‐1 H ‐pyrazole was treated with CH 3 I, the methylation occurres at endocyclic two nitrogens at the same time. The ratio of isomers in products was depended upon the nature of 4‐position substituent in the pyrazole ring. The products were characterized by X‐ray diffraction analysis, and the ratios of isomer were explained by means of the results of ab inito calculation.