Crystal structure determination of rac-11′-(1-acetyl-1H-indazol-3-yl)-11′,11a′-dihydro-10′H,17′H-spiro[indene-2,18′-[5a,16b]methanotriindeno[1,2-b:1′,2′-d:2′′,1′′-g]oxocine]-1,3,10′,12′,17′(10a′H)-pentaone acetonitrile 1.5-solvate