The oxidative cyclization of the ethylidene derivative of 3-hydrazinoacenaphtho[1,2-e][1,2,4]triazine (2) gave regioselectively the angular isomer 1-methylacenaphtho[1,2-e][1,2,4]triazolo[3,4-c][1,2,4]triazine (5). Its linear isomer 10-methylacenaphtho[1,2-e][1,2,4]triazolo[4,3-b][1,2,4]triazine (4) was synthesized by the condensation of acenaphthenequinone (6) with 3,4-diamino-5-methyl-4H-1,2,4-triazole. Condensation of 2 with a number of monosaccharides afforded the respective hydrazones 9 whose oxidative cyclization gave the corresponding 1-(polyhydroxyalkyl)acenaphtho[1,2-e][1,2,4]triazolo[3,4-c][1,2,4]triazine (10). Acetylation of 9 and 10 gave 3-[N-acetyl-N′-(polyacetoxyalkylidene)hydrazino]acenaphtho[1,2-e][1,2,4]triazine (11) and 1-(polyacetoxyalkyl)acenaphtho[1,2-e][1,2,4]triazolo[3,4-c][1,2,4]triazine (13) respectively. Periodate oxidation of 9e gave 3-(2-oxoethylidenehydrazino)acenaphtho[1,2-e][1,2,4]triazine (14).