In the present work a variety of new heterocyclic compounds namely hydrazide, oxadizole, β-lactam, aza-β-lactam were synthesized by Sequential reactions started from alkylation of Sodium saccharin salt by different alkyl halides namely benzyl chloride, n-propyl bromide and sec-butyl bromide than hydrolysis the N-alkyl saccharin derivatives(1a-c)using 10% NaOH to give the N-alkyl sulfamidobenzoic acid derivatives(2a-c).Reaction (2a-c) with ethyl alcohol in presence Conc. sulfuric acid give the corresponding ester derivatives (3a-c). The benzohydrazide derivatives (4a-c) were obtained via reaction of ester derivative with 80% hydrazine hydrate. The cyclization of (4a-c) with carbondisulfide in presence potassium hydroxide gave the corresponding 2-mercapto-1,3,4-oxdiazol derivatives(5a-c). Reaction of (5a-c) with 80% hydrazine hydrate gave 5-hydrazido 1,3,4-oxadiazol derivatives(6ac). The Schiff bases(7a-f) were obtained by condensation of (6a-c) with 2,4-dimethoxybenzaldehyde and pdimethylaminobenzaldehyde. The cyclization of (7a-f) with chloroacetyl chloride and phenylisocynate gave the corresponding β-lactam (8a-f) and aza-B-lactam(9a-f) derivatives. F.T.IR and 1-HNMR were used to characterize the target compounds.