Crystal structure of 3-(3-bromophenyl)-1′,3′-dimethyl-2′ H ,3 H ,4 H -spiro[furo[3, 2- c ]chromene-2,5′-pyrimidine]-2′,4,4′,6′(1′ H ,3′ H ) tetraone, C 22 H 15 BrN 2 O 6