Selenazole. preparation, 2-aminoselenazole

Hofmann (1), of the Zurich School, was the first to have tried unsuccessfully to prepare the unsubstituted parent compound, selenazole much later, in 1955, Metzger and Bailly (2) were equally unsuccessful in trying to prepare selenazole from 2-aminoselenazole by reduction of the diazo compound,... 

The modified Hantzsch synthesis first described by Hofmann <1889LA(250)294> has remained the general method for preparing 1,3-selenazoles. Depending on the substitution required in the selenazole the requisite selenocarboxamide and a-halocarbonyl derivatives are coupled (Scheme 7) <79HC(34)217>. Since a chlorooxirane is isomeric with an a-chlorocarbonyl, 2-aminoselenazoles are also formed with selenourea (Equation (6)) <81T2607>. The synthesis of a 5-quinonyl-l,3-selenazole... 

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