Processes for the production of chlorinated propenes are provided. The present processes make use of 1,2-dichloropropane, a by-product in the production of chlorohydrin, as a low cost starting material, alone or in combination with 1,2,3-trichloropropane. At least one dehydrochlorination is conducted in the gas phase, and is the first process step. The present processes can also generate anhydrous HCl as a byproduct that can be removed from the process and used as a feedstock for other processes, providing further time and cost savings.