New Selenosemicarbazides Derived from Imidazole‐Based Carbohydrazides |
| |
| Authors: | Grzegorz Mlostoń Anthony Linden Heinz Heimgartner |
| |
| Affiliation: | 1. University of ?ód?, Department of Organic and Applied Chemistry, Tamka 12, PL‐91‐403 ?ód?, (phone: +48‐42‐6355761;2. fax: +48‐42‐6655162);3. Organisch‐chemisches Institut, Universit?t Zürich, Winterthurerstrasse 190, CH‐8057 Zürich, (phone: +41‐44‐6354282;4. fax: +41‐44‐6356812) |
| |
| Abstract: | Imidazole‐based carbohydrazides, i.e., 3‐oxidoimidazole‐4‐carbohydrazides 1 and 2‐[(imidazol‐2‐yl)sulfanyl]acetohydrazides 6 , react with aryl isoselenocyanates 4 in MeOH at room temperature to give the corresponding selenosemicarbazides 5 and 7 , respectively, in good yields. On heating 7b in DMF in the presence of air to 100°, 1,3,4‐oxadiazole 8a was formed via cyclization and formal elimination of H2Se. Product 8a was also obtained after heating of a mixture of 4a and 6b under the same conditions. On the other hand, on heating of a solution of 7c in MeOH at reflux, a cyclization occurred to give the corresponding 1,2,4‐triazole‐3‐selone 9b . Again, the same product was formed when a mixture of 4b and 6b was heated in MeOH. Surprisingly, analogous cyclizations of selenosemicarbazides of type 5 under the same conditions failed, and only decomposition was observed. The structures of 7a, 7d , and 9b have been established by X‐ray crystallography. |
| |
| Keywords: | Selenosemicarbazides Carbohydrazides, imidazole‐based X‐Ray crystallography |
|
|
