Fluoranthen und seine Derivate, V. Mitteil.: Substitutions‐Verhältnisse beim α‐Phenyl‐naphthalin

Cyanation of aromatic halides

“…At 100 °C for 5.5 h, the product was a mixture of 70% of 3chlorobenzonitrile and 21% of benzene-1,3-dicarbonitrile. A similar selectivity was demonstrated for trimethylsilyl cyanide toward 4-bromochlorobenzene.52a Polyiodides,14 polybromides,18,22,24 and dichlorides22,58 usually give the corresponding polycarbonitriles but selectivity between two (or more) bromine or chlorine atoms is sometimes possible, for example, when 4,7dibromo-5-nitro-2,l,3-benzothiadiazole is treated with copper® cyanide in DMF at 75 °C, 7-bromo-5-nitro-2,l,3-benzothiadiazole-4-carbonitrile (8) was the sole product.19 2,3-Dichloronitrobenzene is converted into 2-chloro-6-nitrobenzonitrile (9), 16 and the chlorine on the pyran ring of the thiazolylcoumarin (10) is more reactive than those on the thiazole.59 Br Br Replacement of either two or three of the bromine atoms of l,3,5-tribromo-2,4,6-trimethylbenzene (11) by cyano groups is possible under pressure; at 190 °C for 0.75 h, one bromine remains but at 205 °C for 1.3 h all three are displaced to give the trinitrile (Scheme X). 24 The effect of a pair of pyridine-type nitrogens in a 1,2,3-triazole ring more than compensates for the comparatively unreactive nature of chlorine in the preparation of 1,4-diphenyl-1,2,3-triazole-5-carbonitrile ( 12 Examples of a fluorine atom being displaced by cyanide are rare but pentafluoropyridine reacts readily with copper(I) cyanide at 0 °C in DMF to give a 33% yield of 2,3,5,6-tetrafluoropyridine-4-carbonitrile.61 A recent patent62 describes the conversion of 2-fluoropyrazine into the corresponding nitrile (13) and claims that the 2-chloropyrazine gave only a trace of the nitrile.…”

The Chemistry of Fluoranthene.

“…Although bromination, sulfonation, and nitration occur predominantly in the 3-position, von Braun and Anton (16) demonstrated the formation of a small amount of the 8-substituted isomer in each case.…”

“…B. SULFONATION AND NITRATION Goldschmiedt (82) and later von Braun and coworkers (16,18) prepared a fluoranthenedisulfonic acid by warming the hydrocarbon with concentrated sulfuric acid, von Braun also prepared two different monosulfonic acids. 3-Fluoranthenesulfonic acid was obtained either from 3-aminofluoranthene or by direct sulfonation of the hydrocarbon with chlorosulfonic acid in an inert solvent (131).…”

Thermolysis of phenyl-substituted 1,2-dihydronaphthalenes. Evidence for diphenylbutadienes as intermediates

“…dihydronaphthalene (1 6) and (20) are interconverted via the intermediates 1and 2-phenyl-2,3dihydronaphthalene (1 7) and (1 8), respectively, through two consecutive, sigmatropic 1,5hydrogen shifts. In both processes partial oxidation to the corresponding phenylnaphthalenes (21 ) and (22) takes place. The deuterium distribution in the pyrolysis products suggests that in the hot zone diphenylbutadienes are formed, which are reconverted into phenyldihydronaphthalenes upon reaching the cold receiving flask.…”