- A Synthetic Route Toward Tetrazoles: The Thermolysis of Geminal Diazides
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A new synthetic route toward the tetrazole core is described, which is based on a general fragmentation pattern that was found in a range of compounds featuring geminal diazido units. Through a simple two-step procedure, the synthesis of structurally diverse target compounds containing a tetrazole, such as tetrazoloquinoxalinones, benzoylaryltetrazoles, tetrazolotriazinones, and tetrazoloazepinones, was easily accomplished, starting from broadly accessible substrates (i.e., oxindoles, diarylethanones, pyrazolones, and phenanthrols). The initial oxidative diazidation reaction with iodine and sodium azide under mild conditions is followed by the thermal fragmentation under microwave irradiation, leading to the tetrazole products. Noteworthy, an experimental solution is presented in which the potentially hazardous diazide intermediates are not isolated and the concentration of crude reaction mixtures containing diazides is not required to achieve the tetrazoles in good yields.
- Holzschneider, Kristina,Kirsch, Stefan F.,Mohr, Fabian,Tong, My Linh
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- Reaction of Azole Condensed Quinoxaline N-Oxides with Acetic Anhydride
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The reaction of 7-chlorotetrazoloquinoxaline 5-oxide 6a with acetic anhydride gave 7-chloro-5-(7-chlorotetrazoloquinoxalin-4-yl)-4,5-dihydro-4-oxotetrazoloquinoxaline 7a, while the reaction of 7-chloro-1,2,4-triazoloquinoxaline 5-oxide 6b with acetic anhydride afforded 7-chloro-5-(7-chloro-1,2,4-triazoloquinoxalin-4-yl)-4,5-dihydro-4-oxo-1,2,4-triazoloquinoxaline 7b and 7-chloro-4,5-dihydro-4-oxo-1,2,4-triazoloquinoxaline 8b.The reaction of compound 6a or 6b with acetic anhydride/ acetic acid provided 7-chloro-4,5-dihydro-4-oxo-tetrazoloquinoxaline 8a or compound 8b, respectively.
- Kurasawa, Yoshihisa,Hosaka, Tomoyoshi,Matsumoto, Yuko,Ishikura, Aiko,Ikeda, Kazue,et al.
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p. 1697 - 1700
(2007/10/02)
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