'##teamcity[buildProblem' is not recognized as an internal or external command?

I have the below block in a command line build step

:start
echo Starting service "%svc%"
sc \\%system.TargetServiceHost% start "%svc%"
if ERRORLEVEL 1060 goto failedstart
goto end

:failedstart
##teamcity[buildProblem description='Failed to start service "%svc%" on "%system.TargetServiceHost%"']

:end

At the moment the sc command returns error 1060 but the step and build still pass so I tried to invoke failure of the build but I get:

'##teamcity[buildProblem' is not recognized as an internal or external command

Shouldn't Teamcity be parsing that out prior to it trying to be run? Or is my syntax wrong?