"Kop\u0159ivov\u00E1, Radka" . . "RIV/00216275:25310/09:00008308" . . "Drabina, Pavel" . "GB - Spojen\u00E9 kr\u00E1lovstv\u00ED Velk\u00E9 Brit\u00E1nie a Severn\u00EDho Irska" . . "6"^^ . "[7904B3350087]" . . "Ventura, Karel" . . . "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" . "Dyes and Pigments" . . "2" . "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" . . "R\u016F\u017Ei\u010Dka, Ale\u0161" . "0143-7208" . . "5-amino-4-chloro-2; 7-dimethyl-1H-benzimidazole"@en . . . . . "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"@en . "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"@en . "6"^^ . "308707" . "Sedl\u00E1k, Milo\u0161" . . "81" . "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."@en . "25310" . "Panov, Illia" . "RIV/00216275:25310/09:00008308!RIV10-MSM-25310___" . "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." . . "4"^^ . . "Z(MSM0021627501)" . .