id	author	title	date	pages	extension	mime	words	sentence	flesch	summary	cache	txt
eurjchem-1087	El-Wahab, Ashraf Hassan Fekry Abd; Radini, Ibrahim Ali; Mohamed, Hany Mostafa	Synthesis, reactions and applications of pyranotriazolopyrimidines	2014	14	.pdf	application/pdf	6628	419	63	Compounds 38a and 38b were reacted with triethyl orthoformate to give formimidate, 39a and 39b Interaction of compound 39a and 39b with equimolar amount of hydrazine hydrate in absolute ethanol at ambient temperature gave the key intermediates pyranopyrimidine derivatives 40a,b Reaction of compound 40a,b with triethyl orthoformate or ethyl ethoxymethylene cyanoacetate afforded pyranotriazolopyrimidines, 41a,b While treatment of compounds 40a,b with acetic anhydride or acetoacetone gave the corresponding pyranotriazolo pyrimi‐ dines 42a,b and reaction of compounds 40a,b with diethyl oxalate gave the corresponding pyrano triazolo pyrimidines 43a,b. Treating compounds 40a,b with equimolar amount of chloro acid chloride derivatives in dioxane containing catalytic amount of triethylamine afford triazolo derivatives 45a‐d (Scheme 13). Four different possibilities exist for the relative orientation of both rings, so four different isomeric families of compounds are defined: 1,2,4‐triazolo[1,5‐a]pyrimidine (I), 1,2,4‐triazolo[1,5‐c]pyrimi‐ dine (II), 1,2,4‐triazolo[4,3‐a]pyrimidine (III) and 1,2,4‐ triazolo[4,3‐c]pyrimidine (V) (Figure 1).	cache/eurjchem-1087.pdf	txt/eurjchem-1087.txt