A series of pyridopyrazine and pyrimidothiazine derivatives have been synthesized and their activity against FtsZ from Mycobacterium tuberculosis (Mtb) and in vitro antibacterial activity against Mtb H 37Ra and Mtb H 37Rv are reported. Certain analogs described herein showed moderate to good inhibitory activity. © 2011 Elsevier Ltd. All rights reserved.