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Synthesis of 1,3,4‐Oxadiazole Acyclo C ‐Nucleosides Bearing 5‐Methylthio{7‐substituted‐1,2,4‐triazolo[1,5‐ d ]tetrazol‐6‐yl}moieties
Author(s) -
Taha Mamdouh Ahmed Mohamed,
ElBadry Susan Mohamed
Publication year - 2006
Publication title -
journal of the chinese chemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.329
H-Index - 45
eISSN - 2192-6549
pISSN - 0009-4536
DOI - 10.1002/jccs.200600156
Subject(s) - chemistry , acetic anhydride , acetic acid , hydrazide , acetylation , oxadiazole , bromine , medicinal chemistry , organic chemistry , biochemistry , gene , catalysis
Oxidative cyclization of the sugar hydrazones ( 3 a‐f ) derived from {7 H ‐1,2,4‐triazolo[1,5‐ d ]tetrazol‐6‐ylsulfanyl}acetic acid hydrazide ( 1 ) and aldopentoses 2 a‐c or aldohexoses 2 d‐f with bromine in acetic acid in the presence of anhydrous sodium acetate, followed by acetylation with acetic anhydride gave the corresponding 2‐(per‐ O ‐acetyl‐alditol‐l‐yl)‐5‐methylthio{7 H ‐1,2,4‐triazolo[1,5‐ d ]tetrazol‐6‐yl}‐1,3,4‐oxadiazoles ( 5 a‐f ). Condensative cyclization of the sugar hydrazones ( 3 a‐f ) by heating with acetic anhydride gave the corresponding 3‐acetyl‐2‐(per‐ O ‐acetyl‐alditol‐1‐yl)‐2,3‐dihydro‐5‐methylthio{7‐acetyl‐1,2,4‐triazolo[1,5‐ d ]tetrazol‐6‐yl}‐1,3,4‐oxadiazoles ( 11 a‐f ). De‐ O ‐acetylation of the acyclo C ‐nucleoside peracetates ( 5 and 11 ) with methanolic ammonia afforded the hydrazono lactones ( 7 ) and the acyclo C ‐nucleosides ( 12 ), respectively. The structures of new oxadiazole derivatives were confirmed by analytical and spectral data.