N,N-diethyl-4-[(3-methoxyphenyl)-piperidin-4-ylidenemethyl]benzamide N,N-diethyl-4-[(3-methoxyphenyl)-(4-piperidylidene)methyl]benzamide N,N-diethyl-4-[(3-methoxyphenyl)-(4-piperidinylidene)methyl]benzamide N,N-diethyl-4-[(3-methoxyphenyl)-piperidin-4-ylidene-methyl]benzamide