7-Methyl-5-oxo-10,11-dihydro-5H-dibenzo[a,d]cycloheptene-2-carboxylic acid 、
对甲基苯甲醛 以2-carboxy-8-methyl-10,11-dihydro-5-oxo-5H-dibenzo[a,d]cycloheptene having a m.p. of 196°-197° C. was obtained from m-methylbenzaldehyde的产率得到8-Methyl-5-oxo-10,11-dihydro-5H-dibenzo[a,d]cycloheptene-2-carboxylic acid