Synthesis and characterization of fused and spiro heterocycles by ultrasonic methods

1027-1032Treatment of 1,4-diazacyclohexan-2,5-dione 1 with bromine in carbon tetrachloride has yielded 1,4-diaza-3-bromo-2,5-dioxocyclo­hexane 2 and 1,4-diaza-3,3-dibromocyclohexane-2,5-dione 7. The reaction of 2 with carbamides/thiocarbamides has produced 6-oxo-oxazolo[4,5-b] piperazine 5 /2-substituted imino-6-oxo-thia­zolo­[4,5-b] piperazine 6. Compound 7 on combination with carba­mides/ thiocarbamides is transformed to 1-oxo-2-substi­tuted imino-3,5,8-triaza-3H,5H,8H,7-dihydro-6,9-dioxo-spiro [3.5] non­­ane 9 and 1-thia-2-substituted imino-3,5,8-triaza-3H,5H,8H-7dihydro-6,9-dioxo-spiro [3.5] nonane 9. The structures of the synthesized compounds have been confirmed by IR, 1H and 13C NMR spectral data analyses