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Z. Naturforsch. 2012,
67b, 913 – 920
doi:10.5560/ZNB.2012-0124
Orthoamides and Iminium Salts LXXXII. The Cleavage of Orthoamides of Alkynecarboxylic Acids by Trimethylsilyl Azide
Orthoamide und Iminiumsalze, LXXXII. Die Spaltung von Alkincarbonsäure-orthoamiden mit Trimethylsilylazid
1 Fakultät Chemie/Organische Chemie, Hochschule Aalen, Beethovenstr. 1, D-73430 Aalen, Germany
2 Institut für Organische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
Reprint requests to Prof. Dr. Willi Kantlehner. Fax: +49(7361)5762250. E-mail:
willi.kantlehner@htw-aalen.de
Received May 7, 2012 / published online September 20, 2012
Herrn Professor Klaus Hafner zum 85. Geburtstag gewidmet
The cleavage of orthoamides of alkynecarboxylic acids 5 with trimethylsilyl azide affords 4-[bis(dimethylamino)methylene]-4H-1,2,3-triazoles 9. By treatment of the bis-orthoamide of acetylenedicarboxylic acid 1 with trimethylsilyl azide and benzoyl azide, respectively, the 5-[bis(dimethylamino)methylene]-5H-1,2,3-triazole carboxamidinium salt 12a is accessible. Iminium salts 10 and 14 can be prepared by methylation of the triazoles 9 and 12a in 2-position of the triazole ring. The crystal structure of 5H-1,2,3-triazole-4-carboxamidinium tetraphenylborate 12b is reported.
Key words: Orthoamides, Alkynecarboxylic Acids, Cleavage, Trimethylsilyl Azide, Ketene Aminals, 1,2,3-Triazole-4-carboxamidinium Salts, Crystal Structure Analysis