Synthesis of methyl 4 chloro benzoate A mixture of 4-chloro benzoic acid in 25 ml methanol

Synthesis of methyl 4 chloro benzoate
A mixture of 4-chloro benzoic acid in 25 ml methanol, and then add con.Sulfuric acid dropwise through a dropping funnel. The solution was heated to reflux for 6 hours, cooled to room temperature and poured into an equal volume of water.
Synthesis of 4-chlorobenzohydrazide
Take Methyl 4 chlorobenzoate and 25 ml ethanol and dropwise hydrazine hydrate mix well .The solution was heated at reflux temperature for 6-8 hours. The reaction mixture was cooled to room temperature.A white solid product is obtained and re-crystallized from ethanol.
Synthesis of 4 –chloro- N’-(3-nitrobenzylidine)benzohydrazide
Equimolar quantities of 3-nitrobenzaldehyde and 4–chloro- N (3-nitrobenzylidine)benzohydrazide dissolved in ethanol are taken in a round bottom flask and was refluxed for 3-4 hours and solid was used for the next step and the completion of reaction monitored by TLC.
Synthesis of 2-(3-(4-Chlorobenzamido)-2-(3-nitrophenyl) -4 oxo-thiazolidine-5-yl)-acetic acid (B)
A mixture of Schiff base and thiomalic acid in 1,4 dioxane was added to anhydrous ZnCl2 in RBF then heated for 22-24 hours. After completion of the reaction indicated by TLC.