Synthesis of 2-R-5-amino-4-(1H-tetrazol-5-yl)-1,3-oxazoles from 2-R-5-amino-1,3-oxazole-4-carbonitriles

This short communication reports about new 5-amino-4-(1H-tetrazol-5-yl)-1,3-oxazoles which were synthesized by [3+2] cycloaddition of 2-R-5-amino-1,3-oxazole-4-carbonitriles and trimethylsilyl azide with dibutyltin oxide present. The reaction conditions provided high yields of the products, and were tolerant to some active functional fragments in the oxazole substituents (amino, amido, and hydroxy group). In the case of 2-((4-cyano-2-phenyloxazol-5-yl)amino)-N-methylacetamide the by-product (N-((1-(2-(methylamino)-2-oxoethyl)-1H-tetrazol-5-yl)(1H-tetrazol-5-yl)methyl)-benzamide) was formed together with the expected tetrazolyloxazole.