Synthesis of azido derivatives of mucobromic acid

Mucobromic acid is a highly reactive multicentered molecule. It was converted to its corresponding but unstable diazido derivative by reaction with two equivalents of sodium azide. The resultant 3,4-diazido-5-hydroxyfuran-2(5H)-one was obtained in moderate yield (42%) but decomposed readily even at low temperatures. Its more stable analogue 3,4-diazido-5-methoxyfuran-2(5H)-one was obtained in excellent yield after reacting 5-methoxy-3,4-dibromofuranone with two equivalents of sodium azide. The 4,5-dibromopyridazinones which are in effect masked mucobromic acid derivatives, underwent nucleophilic substitution reactions with various nucleophiles, including azides and afforded corresponding azidopyridazinones in good yields. The synthesized azido-furanone and pyridazinone derivatives are earmarked for click reactions. KEY WORDS: 3,4-Diazido-5-hydroxyfuran-2(5H)-one, 3,4-diazido-5-methoxyfuran-2(5H)-one, 4,5-Diazidopyridazinones, Mucobromic acid Bull. Chem. Soc. Ethiop. 2013, 27(1), 151-154. DOI: http://dx.doi.org/10.4314/bcse.v27i1.17