Unfortunately, it seems that you cannot run multi-command in one time. See the Restrictions of the exec command for ACI:
Azure Container Instances currently supports launching a single process with az container exec, and you cannot pass command arguments. For example, you cannot chain commands like in sh -c "echo FOO && echo BAR", or execute echo FOO.
You just can execute the command such as whoami, ls and etc in the CLI command.
I suggest that you can run the command to create an interactive session with the container instance to execute command continuously after you create the ACI, refer to this similar issue.