Treatment of 4-aminobenzoyl hydrazide (1) with (CS2) and potassium hydroxide in absolute (EtOH) resulted in formation of 5-(4-aminophenyl)-2-thiol-1,3,4-oxadiazole (2). Compound (2) has been converted to the diazonium salt which reacted with 2-hydroxybenzaldehyde for producing the aldehyde derivative (3). Reaction of compound (3) with (4-nitroaniline, 3-nitroaniline, 2-nitroaniline, 4-chloroaniline, 2-chloroaniline, 2,4-dichloroaniline and 4-bromoaniline) by (MW) method in (EtOH) afforded seven Schiff bases (4a–g). Cycloaddition of imines (4a–g) with phthalic anhydride in microwave oven gave seven 1,3-benzoxazepine-1,5-diones (5a–g) bearing oxadiazole moiety. Screening verves of final benzoxazepines was done on Staphylococcus aurous and Escherichia coli. The implications explained that compounds (5b, 5c, 5d, 5e, 5f and 5g) possess higher effect than gentamycin against Staphylococcus aurous. Moreover, the 1,3-oxazepine-1,5-diones (compounds 5a, 5b, 5c, 5d, and 5g) appeared better action against Escherichia coli comparably with the standard antibiotic.

Azo-aldehyde derivative (2) was prepared through reaction of 2-hydroxybenzaldehyde with diazonium ion generated from 2-aminobenzothiazole (1). The producing aldehyde (2) was then treated with some anilines consisting (4-nitroaniline, 3-nitroaniline, 4-aminophenol, 4-methoxyaniline, 4-bromoaniline, 4-chloroaniline and 2,4-dichloroaniline) by (MW) method to give seven Schiff bases (3a-g). Cyloaddition reactions of Schiff bases (3a-g) and phthalic anhydride utilizing (MW) means in dry benzene yielded seven new 1,3-benzoxazepine-1,5-diones (4a-g) carrying the unit of benzothiazole. Determination of verves of final benoxazepines athwart bacteria done on Staphylococcus aurous (Gram-positive) and Escherichia coli (Gram-negative). The outputs showed that all benzoxazepine compounds exhibited greater activity to standard antibiotic (gentamycin) athwart Staphylococcus aurous. Moreover, the benzoxazepines (4a, 4b, 4c, 4d, 4e and 4g) appeared best activity athwart Escherichia coli comparably with that of standard antibiotic.