Isoselenocyanic acid

Cyclohexylamino-l,2,3,4-selenatriazole (29) dissociated into hydrazoic acid and isoselenocyanate on attempted isolation (equation 13) (82UP42800). Monosubstituted 5-amino-l,2,3,4-thiatriazoles also undergo this type of ring cleavage, although only in the presence of base (see Section 4.28.2.4.1). 

A review on the acid promoted decomposition of a-diazoketones contains some steroidal examples.88 The full account was reported of the conversion of a-azido-ketones into cyano-carboxylic acids promoted by bromine in acetic acid.89 A general review on new reagents in natural product chemistry included the deamination of amines via the isonitriles, isothiocyanates, and isoselenocyanates reported... 

Carboxylic acid selenoamides Isoselenocyanates Selenocyanates Selenoiminoesters... 

Examples of well-established 1,3,4-thiadiazole syntheses have been extended to the production and study of their selenium analogues." 1,4-Disubstituted selenosemicarbazides (191 R = Aik, Ar, or Ac) are readily accessible in good yield by the addition of isoselenocyanate esters (including benzoyl isoselenocyanate) to acylhydrazines." Their cyclization in acidic media affords the stable crystalline 1,3,4-selenadiazoles (192 R = Aik, Ar, or Ac) " the members of the aroylamino-series are stable to alkalis, but are hydrolysable by acids to the parent amines (192 R = H) these are convertible into conventional derivatives, as expected." Bis-selenoureas of type (194) are similarly accessible, but usually cyclize spontaneously to the substituted 2,5-dianilino-1,3,4-selenadiazoles (195). The action of acetic anhydride on (194) yields diacetyl derivatives of (195)... 

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