my $h1 = {
	'drug comparison' => 
	{
          '7003000.xml' => {
                             'entity' => 'a1, a2, a3'
                           },
          '70037559.xml' => {
                              'entity' => 'x1, x2, x3'
                            }
        }
};
my $copy = do{my $VAR1; eval Dumper $h1; $VAR1;};