The current dye intermediate market - A cautionary tale and detective story; characterization and unambiguous synthesis of 5-amino-4-chloro-2,7-dimethyl-1H-benzimidazole

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216275%3A25310%2F09%3A00008308" target="_blank" >RIV/00216275:25310/09:00008308 - isvavai.cz</a>

Result on the web

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DOI - Digital Object Identifier

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Result language

angličtina

Original language name

The current dye intermediate market - A cautionary tale and detective story; characterization and unambiguous synthesis of 5-amino-4-chloro-2,7-dimethyl-1H-benzimidazole

Original language description

Commercially delivered 2-chloro-5-methyl-1,4-phenylenediamine (1 metric ton) was not identical to the commonly used dye intermediate; it was found that the material was a pure but not yet described molecule. H-1, C-13 NMR, MS, microanalysis and X-ray diffraction showed that the substance was in fact 5-amino-4-chloro-2,7-dimethyl-1H-benzimidazole. The manufacturer's mistake was explained by independent synthesis, which revealed that the key step was nitration of N-(5-chloro-2-methyl-4-nitrophenyl)acetamide giving N-(5-chloro-2-methyl-4,6-dinitrophenyl)acetamide, which requires Fe(III) catalysis. Subsequent reduction of N-(5-chloro-2-methyl-4,6-dinitrophenyl)acetamide with hydrogen and Pd/C catalyst exclusively gives N-(2,4-diamino-3-chloro-6-methylphenyl)acetamide. The ring closure reaction giving 5-amino-4-chloro-2,7-dimethyl-1H-benzimidazole takes place during the reduction with iron.

Czech name

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Czech description

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Type

J_x - Unclassified - Peer-reviewed scientific article (Jimp, Jsc and Jost)

CEP classification

CC - Organic chemistry

OECD FORD branch

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Project

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Continuities

Z - Vyzkumny zamer (s odkazem do CEZ)

Publication year

2009

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Dyes and Pigments

ISSN

0143-7208

e-ISSN

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Volume of the periodical

81

Issue of the periodical within the volume

2

Country of publishing house

GB - UNITED KINGDOM

Number of pages

6

Pages from-to

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UT code for WoS article

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EID of the result in the Scopus database

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