I personally like to start a sentence with..
In order to quell/quench Baghdad uprisings, they unleashed poison gas on Baghdad's people. (if you are talking about the 1991 Baghdad uprisings)
But you can also start with To if you like.
I dont think carpet drop poison gas is an appropriate term; I have only heard of carpet bombing .
The Baghdad uprising? was there a particular uprising, if so , yes, you can use the Baghdad uprising.