5-Allylidene-10,11-dihydro-5H-dibenzo[a,d][7]annulene; 2-prop-2-enylidenetricyclo[9.4.0.03,8]pentadeca-1(15),3,5,7,11,13-hexaene; 10,11-Dihydro-5-(2-propenylidene)-5H-dibenzo[a,d]cycloheptene; 5-Allylidene-10,11-dihydro-5H-dibenzo[a,d]cycloheptene; 10,11-Dihydro-5-(2-propen-1-ylidene)-5H-dibenzo[a,d]cycloheptene; Nortriptyline EP Impurity H