1,1'-(Phenylethylethylene)bis(4-phenylisonipecotic acid) diethyl ester maleate (1:1) 13451-63-3 ISONIPECOTIC ACID, 1,1'-(PHENYLETHYLENE)BIS(4-PHENYL-, DIETHYL ESTER, MALEATE (1 Isonipecotic acid, 1,1'-(phenylethylene)bis(4-phenyl-, diethyl ester, maleate (1:1)