“…2,4]triazole-3-thione 138, by reaction with p-methoxyphenyl isothiocyanate and phenyl isothiocyanate respectively, followed by treatment with sodium hydroxide. Treatment of 135 with carbon disulfide in basic medium resulted [174] in the formation of 5-(6,7,8,9-tetrahydro-5H-[1,2,4]triazolo[1,5-a]azepin-2-yl)methyl-[1, 3,4]oxadiazole-2-thione 139, while treatment of 135b with cyanobromide afforded the 5-((1,5-diethyl-1H-1,2,4-triazol-3-yl)methyl)-1,3,4-oxadiazole-2-thione 140. The alkaline hydrolysis of 135a, followed by acidification with HCl, furnished the 2-(6,7,8,9-tetrahydro-5H-[1,2,4]triazolo[1,5-a]azepin-2-yl)acetic acid 141.…”