msbuild failes when building resources if DEFINES in pro file

Add define to pro file:
DEFINES += "APPNAME=\\\"MYAPPNAME\\\""

Create visual studio project:
qmake -tp vc

Build project with msbuild:
msbuild
-> error RC2104: undefined keyword or key name: MYAPPNAME

This worked with 4.8.4 but not with 5.0.1 nor 5.0.2. Building with nmake works in all versions.

There are differences between 4.8.4 and 5.0.2 vcxproj files.
In Qt5 there is "<PreprocessorDefinitions> ...APPNAME="MYAPPNAME" ...."
and in Qt4
"<PreprocessorDefinitions> ... APPNAME=\"MYAPPNAME\&quot ..."
When adding missing backslashes to Qt5 vcxproj file, msbuild success building resources.