126048-33-7 2,7-Difluoro-4-methoxyspiro-(9H-fluorene-9,4'-imidazolidine)-2',5'-dione AL 3152 AL-3152 Alo 3152 Spiro(9H-fluorene-9,4'-imidazolidine)-2',5'-dione, 2,7-difluoro-4-methoxy-