Synthesis of 2-substituted naphtho[1′,2′:4,5]thiazolo[3,2-b]-1,2,4-triazoles

N-Amination of 2-aminonaphtho1,2-d]thiazole ( 1 ) with O-mesitylenesulfonylhydroxylamine ( 2 ) afforded the corresponding 2,3-diaminonaphthothiazolium salt 3a . Cyclocondensation of 3a or its free base 3b with appropriate carboxylic acid derivatives 4a-f gave the title compounds 5a-f in satisfactory yields (54–95%). Structures of the products were assigned on the bases of spectral and elemental analyses.