33913-15-4Relevant articles and documents
Highly Efficient and Practical Synthesis of the Key Intermediate of Telmisartan
Zhao, Jianhong,Xiong, Yicheng,Yang, Wu-Lin,Yang, Fan,Jin, Yu
, p. 1022 - 1027 (2021/04/12)
We reported herein an efficient and practical method to access 1,7′-dimethyl-2′-propyl-2,5′-bi(1H-benzimidazole) 1, a key intermediate for the synthesis of telmisartan. The synthetic route was based on readily available o-methylaniline as the starting material, and the target product 1 was prepared through a six-step process, including amidation, formylation, cyclization, hydrolysis, amidine, and oxidation. The overall yield for the preparation of 1 was 51.5% on the 100 g scale, with a purity of 99.91%. The salient features of this method include economic and easily available starting materials, operational simplicity, and environmentally friendly, which is suitable for the industrial production.
PROCESS AND INTERMEDIATES FOR THE PREPARATION OF BENZIMIDAZOLECARBOXYLIC ACIDS
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Page/Page column 7, (2011/01/12)
Substituted benzimidazolecarboxylic acids of formula (I), wherein R1 and R2 independently are hydrogen, C1-6 alkyl or C3-6 cycloalkyl, are prepared in a four-step synthesis starting from N-acyl-4-haloanilines of formula (II), wherein R1 is as defined above, R3 is C1-4 alkyl and X is chlorine or bromine.
Method for producing n-butyryl-4-amino-3-methyl-methyl benzoate and the novel compound n-(4-bromine-2-methylphenyl)-butanamide
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, (2008/06/13)
According to the invention, N-butyryl-4amino-3-methyl-methyl benzoate is obtained in a particularly advantageous manner by, initially, reacting o-toluidine with butyric acid chloride, by brominating the reaction product and by reacting the bromide obtaine