We resolved 1,2-diphenylethylamine (DPEA) into its (S)- and (R)-enantiomer and used them as precursors for synthesis of (S)- and (R)-1-(1,2-diphenylethyl)piperidine, flexible homeomorphs of the NMDA channel blocker MK-801. We also describe the synthesis of the dicyclohexyl analogues of DPEA. These and related compounds were tested as inhibitors of [(3)H]MK-801 binding to rat brain membranes. St...

for a graph $g$, let $p(g,lambda)$ denote the chromatic polynomial of $g$. two graphs $g$ and $h$ are chromatically equivalent if they share the same chromatic polynomial. a graph $g$ is chromatically unique if any graph chromatically equivalent to $g$ is isomorphic to $g$. a $k_4$-homeomorph is a subdivision of the complete graph $k_4$. in this paper, we determine a family of chromatically uni...

Let P (G,λ) be the chromatic polynomial of a graph G. Two graphs G and H are said to be chromatically equivalent, denoted G ∼ H, if P (G,λ) = P (H,λ). We write [G] = {H |H ∼ G}. If [G] = {G}, then G is said to be chromatically unique. A K4-homeomorph denoted by K4(a, b, c, d, e, f) if the six edges of complete graph K4 are replaced by the six paths of length a, b, c, d, e, f respectively. In th...

For a graph G, let P (G,λ) denote the chromatic polynomial of G. Two graphs G and H are chromatically equivalent (or simply χ−equivalent), denoted by G ∼ H, if P (G,λ) = P (H,λ). A graph G is chromatically unique (or simply χ−unique) if for any graph H such as H ∼ G, we have H ∼= G, i.e, H is isomorphic to G. A K4-homeomorph is a subdivision of the complete graph K4. In this paper, we discuss a...