Synthesis and Characterization of Some NewBis- 1,3-Oxazepines-4,7- Dione and Bis-1,5-Disubstituted tetrazoles Linked to Benzothiazole and Thiadiazole Moieties and Containing Two Azo groups

Abstract

This work includes synthesis of six bis-1,3-oxazepines-4,7-dione [5-7] , [9-11] and
two bis-1,5-disubstituted tetrazoles [8] and [12] starting from 5,5'-(1,4-phenylenebis(diazene-
1,2-diyl))bis(2-hydroxybenzaldehyde) [2] and primary amines 5-amino-1,3,4-thiadiazole-2-thiol
and 2-aminobenzothiazole .Firstlybis-azoaldehyde derivative[2] was prepared through coupling
reaction between P-phenylenediamine [1] and 2-hydroxy benzaldehyde.The compound [2] was
then converted to the correspondingbis- imines [3] and [4] viacondensation reaction with each
primary amines 5-amino-1,3,4-thiadiazole-2-thiol and2-amino benzothiazole,respectively , in
presence of glacial acetic acid as catalyst in absolute ethanol .The bis-imines [3] and [4] were
then introduced in [2+5] cycloaddition reaction with each maleic anhydride , phthalic anhydride
and 3-nitrophthalic anhydride respectively ,in dry benzene to give bis-1,3-oxazepines-4,7-dione
[5-7] and [9-11] ,respectively .Treatment ofbis- imines [3] and [4] with sodium azide under
[2+3]cycloaddition conditions in tetrahydrofuran as solvent resulted the formation of new bis-
1,5-disubstitutedtetrazoles [8] and [12], respectively.The structures of the prepared compounds
were confirmed by C.H.N. elementary analysis and the spectroscopic methods including FTIR,
1H NMR and 13C NMRspectra.These new derivatives probably have some biological activity.