1,3-Thiazol derivatives have been synthesized via reaction of 1-(1-(5,6-dimethoxy-2-oxobenzo[d]thiazol-3(2H)-yl)propan-2-ylidene)-4-substituted thiosemicarbazide with different halides, namely, ethyl bromoacetate, ethyl-2-bromopropionate, phenacyl bromide, p-bromophenacyl bromide and/or substituted hydrazonoyl halides. The new compounds were evaluated as antimicrobial agents.