Synthesis and Characterization of Oxazepine and Oxazepane from reaction of (5,5-Diethyl-4,6~dioxotetrahydro- pyrimidin-2-ylidein)-thiourea and 1,3-Bis(5,5- diethyl-4,6-dioxo-tetrahydro-pyrimidin .. 2-ylidein)-thiourea with maleic and Succinic anhydride

(5,5-Diethyl-4,6-dioxo-tetrahydro-pyrimidin-2-ylidein)-thiourea and I ,3-Bis(5,5- diethyl-4,6-dioxo-tetrahydro-pyrimidin-2-ylidein)-thiourea were pn;~pared by condensation of Thiourea with one equivalent and tow equivalent of 5,5-Diethylpyrimidine- 2A,6-trione. These Schiff-bas were reacted with one equivalent of maleic , succinic and phthalic anhydride in absolute ethanol to give 7-membered heterocyclic ring system of 3,3-Diethyl-2,4,8-tetraoxo-7-oxa-1 ,5, 12-triaza-spiro(5.6)dodec-9-ene- 12-carbothioic acid amid~ and were reacted with tow equivalent :. f maleic and succinic anhydride in same solvent give 2 (7-membered) heterocyclic ring system of 12-(3,3-Diethyl-2,4,8, 11-tetraoxo-7 -oxa-1 ,5, 12-triaza-spiro[ 5 .6]dodecane-12- carbothioyl)-3-ethyl-3-methyl-7-oxa-l ,5, 12-triaza-spiro[5.6]dodec-9-ene-2,4,8, 11- tetraone. The final products were identified by there m.ps, elemental analyses,IR, 1HNMR. and UV-Visible spectra..