Compounds Affecting the Central Nervous System. IV. Substituted 2-Benzyl-3-dialkylaminoalkylindenes and Related Compounds

Thermochemistry of phenyl-substituted benzobicyclo[3.1.0]hex-2-enes. Evidence for carbenes as intermediates

“…The external ring opening leads to biradical 62, and 1,2-H shifts in 62 produce 2-benzylideneindan16 (60) and 2-benzyl-l/f-indene (63). 23 Both radical sites in 62 are benzylic, and, therefore, it will be favored over the biradical 64 produced from internal ring opening (route A) in which only one of the radical sites is benzylic. Nevertheless, the products of path A (55, 51, and 59) still make up a substantial portion of the total amount of product: it seems that interal ring opening in these bicyclic compounds is intrinsically more favorable than external ring opening, a phenomenon that was already observed in FVP of the parent compound 21.…”

“…Phenyl-substituted 1,2-dihydronaphthalenes 44, 47, 51, and 55 are among the major products. Comparison of the plots of the pyrolysis product composition of the 1,2-dihydronaphthalenes vs. pyrolysis temperature with similar plots of the title compounds (22)(23)(24)(25) suggested that some of the minor products, viz., the 1,2-divinylbenzenes 31, 42, and 49, are formed via carbenes 30, 41, 50,57, and 61 rather than via biradicals. Especially at higher pyrolysis temperatures, a large amount of an oxidation product, viz., 1or 2-phenylnaphthalene (48 or 54), is formed.…”

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The thermal rearrangements of benzobicyclo[3.1.0]hex-2-ene (21) and its phenyl-substituted analogues [22][23][24][25] (Scheme V) as models of sterically constrained phenylcyclopropanes have been studied by means of flash vacuum pyrolysis. In most cases the major pathway was cleavage of the "internal" C(l)-C(5) cyclopropane bond followed by a 1,2-hydrogen or a 1,2-phenyl shift in the resulting biradical.

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DARK Classics in Chemical Neuroscience: Etonitazene and Related Benzimidazoles

“…As an even major departure from the etonitazene-type structure, replacement of the benzimidazole nitrogen atoms substantially decreased but not completely eliminated antinociception in the hot-plate and tail-clip assays in mice (Figure ). In this 2-benzylindene series, several of the most active compounds (for example, 77 , 78 , 79 , 80 , and 81 ) had potencies comparable to those of codeine and pethidine, but their effects appeared to be “non-morphine-like”. The antinociceptive effect of some 2-phenylindoles 82 , 83 , and 84 ( Figure ), devised as analogues of the psychotropic tryptamine, was reported to be “markedly weak” .…”