Synthesis and characterization of fused and spiro heterocycles by ultrasonic methods

Abstract

Treatment of 1,4-diazacyclohexan-2,5-dione <b style="">1</b> with bromine in carbon tetrachloride has yielded 1,4-diaza-3-bromo-2,5-dioxocyclo­hexane <b style="">2</b> and 1,4-diaza-3,3-dibromocyclohexane-2,5-dione <b style="">7</b>. The reaction of <b style="">2</b> with carbamides/thiocarbamides has produced 6-oxo-oxazolo[4,5-<i style="">b</i>] piperazine <b style="">5</b> /2-substituted imino-6-oxo-thia­zolo­[4,5-<i style="">b</i>] piperazine <b style="">6</b>.<b style=""> </b>Compound<b style=""> 7</b> on combination with carba­mides/ thiocarbamides is transformed to 1-oxo-2-substi­tuted imino-3,5,8-triaza-3<i style="">H</i>,5<i style="">H</i>,8<i style="">H</i>,7-dihydro-6,9-dioxo-spiro [3.5] non­­ane <b style="">9</b> and 1-thia-2-substituted imino-3,5,8-triaza-3<i style="">H</i>,5<i style="">H</i>,8<i style="">H</i>-7dihydro-6,9-dioxo-spiro [3.5] nonane <b style="">9</b>. The structures of the synthesized compounds have been confirmed by IR, ¹H and ¹³C NMR spectral data analyses.