Synthesis and In Vitro Opioid Receptor Functional Antagonism of Analogues of the Selective Kappa Opioid Receptor Antagonist (3 R )-7-Hydroxy- N -((1 S )-1-{[(3 R ,4 R )-4-(3-hydroxyphenyl)-3,4-dimethyl-1-piperidinyl]methyl}-2-methylpropyl)-1,2,3,4-tetrahydro-3-isoquinolinecarboxamide (JDTic)