1.2.3- Selenadiazoles reactions with amines

As would be expected, nucleophilic attack on the derivatives (84) leads to ring-opening reactions with alcoholic sodium hydroxide to give the selenadiazole (85) and with amines to give compounds (86) (66BP1610). There appears to be no tendency to recyclize, as in the case of the corresponding oxygen and sulfur heterocycles (Scheme 4). 

The 1,2,3-selenadiazoles (139-141) have potent antibacterial and antifungal activity." Similarly, 2-, 3-, and 4-pyridyl-l,4-diselenafulvenes as well as their parent 1,2,3-selenadiazoles are reported to have significant antibacterial activity. The 1,2,3-selenadiazoles and ethynylselenolate salts derived from the selenadiazoles have been variously used as synthetic reagents. Thus, Malek-Yazdi and Yalpani have prepared selenoamides (144) quantitatively from reaction of 4-substituted 1,2,3-selenadiazoles with amines containing potassium hydroxide [Eq. (35)]. 

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