1,2,5-Selenadiazole, 3,4-dicyano

Reaction of DAMN with selenium dioxide forms 3,4-dicyano-1,2,5-selenadiazole (146) (57MI1). This material is the key ingredient for the synthesis of dimethyl diaminomaleate (147) (Scheme 54) (74USP3849479). Surprisingly, 147 cannot be obtained through hydrolysis of DAMN. 

Oxidation of fused 1,2,3-selenadiazole 223 with 2,3-dichloro-5,6-dicyano-l,4-benzoquinone (DDQ) at room temperature gave naphtho[l,2-<7][l,2,3]selenadiazole 88 in 55% yield (Equation 26) <2000JHC1325>. Reaction of compound 224 with selenium powder in an equimolar ratio in an inert atmosphere gave aromatized product 225 (Equation 27) <1998JCM784>. 

The macrocycle tetrakis(selenadiazole)porphyrazine and its Mg(n) and Cu(n) complexes were prepared <1999MI371>. Reaction of the 3,4-dicyano-l, 2,5-sclcnodiazole 81 with magnesium propylate in propanol gave Mg(ll) complex with water and acetic acid 203 (Scheme 29). The Mg(ll) complex 203 was transformed to compounds 232 and 233 as shown. 

Cyano-l,2,5-selenadiazole-3-carbothioamide 237 was obtained by the reaction of 3,4-dicyano-1,2,5-sclcnadiazole 81 with thioacetic acid in benzene in 73% yield (Equation 31) <1998PCA9021>. 

The reaction of diaminomaleodinitrile with Se02 in acetonitrile or CH2C12 gave 3,4-dicyano-l,2,5-selenadiazole 81 in 96-97% yield (Equation 37) <1998PCA9021, 1999MI371>. 

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