The 4D Client application is not capable of compiling a structure. Compilation can only be done with 4th Dimension registered with a Developer Edition license ("4D Developer Edition V 2004" or "4D Server 2004 Developer Edition") .
Note that 4D Client can check syntax and generate typing.
Why Compile your Database?
Build options and licensing with 4D 2004 (Client/Server)
How to check programmatically if database is compiled