Dedicated to Professor Fritz Micheel on the occasion of his 65th birthdayInvestigations carriedout during the last six years have shown that, as in the case of benzene, an extra bond can be introduced into heteroaromatic rings. Since this possibility does not appear to be confined to exceprional cases, the heterocyclic arynes (hetarynes) promise a much wider variety than the carbocyclic arynes. Hetarynes occur mainly as intermediates in nucleophilic substitutions on halogenated heterocyclic compounds. Since the replacement of a C H group in dehydrobenzene by a nitrogen atom and the condensation of benzene rings have stabilizing effects, the stability of hetarynes is expected to increase with the number of N atoms and with the number of condensed aromatic rings.

The mass spectrum of (4) includes the following strong signals: Mf = 318 (100 %), 319 (45 %), 317 (35 %), 315 (15 %), 313 (12 %), 303 (26 %), 302 (40 %), 289 (25 %), 276 (11 %), 189 (36 %), 165 (21 %), 153 (16 %), 129 (14 %), 128 (12 %).The fact that the molecular ion gives the strongest signal indicates a stable, fully conjugated molecule. The low intensity of the fragment with m/e = 165 indicates further that the fluorenyl group is attached by a double bond. IR (KI): v = 1621 cm-I,

infrared and ultraviolet spectra and optical rotation) of the natural and synthetic products. Glycosidation of (2) was also effected when sodium iodide was used instead of silver perchlorate, or even without addition of either of these compounds, although then more vigorous reaction conditions were required. In this way we obtained a glucoside of uric acid from (2) and a-acetobromoglucose. This had the same ultraviolet spectrum (measured at pH 1, 7, and 14) as (1). This product, so far unknown in nature, is therefore a 3-glucosyluric acid. Received, January 23rd. 1963 [Z 435/263 IE] [l] Communication No. 18 on organosilicon compounds; Communication No.We have found that p-nitrosotoluene rapidly adds on one equivalent of sodium to form a deep green, apparently colloidal solution of the free radical (1) when shaken under nitrogen with powdered sodium in dry ether at 5-10°C. The multilineal electron spin resonance spectrum [l] shows that the unpaired electron is located to a considerable extent in the benzene ring. The free radical ( I ) is converted by shaking for 1 hour with excess sodium into the reddish-brown substance (3), which is insoluble in ether and which reforms the green radical when shaken with oxygen (0.5 mole). f IThe same reaction in tetrahydrofuran leads to a red solution of (3), which is transformed to a clear deep-green solution of (1) by measured addition of oxygen. In this solution, about 25 % of the monosodium adduct exist in the free radical form (ESR measurement). Hence (1) is probably in equilibrium with a dimer (5), which possesses no unpaired electrons. Hydrolysis of (1) gives a 48 % yield of 4,4'-azoxytoluene, very predominandy in the cis-form [2]; N-@-tol yl)hydroxylamine is formed by hydrolysis of (3). p-Nitrosodimethylaniline shows the same behaviour towards sodium asp-nitrosotoluene; the free radical (2) formed (ESRspectrum) is bluish-green, and the compound (4) is red and has no free radical character. We have not yet succeeded in detecting a monosodium adduct of nitrosobenzene with an unpaired electron.When its solution in ether is shaken under nitrogen at 2OoC with powdered sodium, diazofluorene ( I ) rapidly adds on a sodium atom to form a deep-blue free radical (2). which is very sensitive to oxygen. According to electron spin resonance measurements, about 60 ' %, of the sodium adduct exist in the freeradical form. Anequilibriumis therefore assumed between (2) and a dimer with no unpaired electron.When (2) is hydrolysed under nitrogen, bifluorenyl (3) is formed in 32 % yield. Hydrolysis in the presence of oxygen gives 28 % bifluorenylidene and 34 % fluorenoneazine.The deep-blue solution containing the free radical (ESRspectrum) of the monosodium compound with the canonical form (4) obtained from diphenyldiazomethane [l] behaves similarly upon hydrolysis. Unlike other comparable free radicals [2,3], the radicals (2) and (4) do not take up a second sodium atom under the roaction conditions stated. I J ) (4)Om mole of nitrogen is rapidly released from phenyl azide (5) by the action...

with a coupling constant of 16 Hz. The signal of the phenyl protons ortho to the imino nitrogen atom is a multiplet centered at 7 = 2.4 (relative intensity 2); and that of the remaining aromatic protons is a multiplet centered at T ~ 2.8 (relative intensity 8). Analogous substances provide an indication of the shift of signals of the CH2 protons on the four-membered ring to lower field owing to the neighboring nitrogen atom. Further, we also derive structure ( I ) from the mass spectrum, specifically from the appearance of the ion M-42 and of a fragment at m ' e 42 (H~C-N-CHZ). The compound is found to have molecular weight 234. The UV spectrum (in alcohol) includes a n absorption band at 244 nm (E = 12200). In the I R spectrum (KBr) the C = N absorption is at 6.2 pm and, remarkably, three absorption bands occur between 9.98 p n and 10.16 pm. It is tempting t o ascribe the formation of ( I ) to addition of ketene phenyl imine t o phenylazirine. According t o Smolinsk y 111, phenylazirine and ketene phenylimine coexist after pyrolysis of c/.-azidostyrene. The characteristic ketene imine absorption[ll at 5 pm in the IR spectrum of our reaction mixture after photolysis can be explained by presence of a small amount of ketene phenyl imine. However, no trace of ( I ) is t o be found in the gas chromatogram after pyrolysis of a-azidostyrene at 350 "C. Nor is any trace of ( I ) t o be found in the mixture obtained o n addition of azidostyrene t o boiling phenylazirine (ca. 180 "C). From our results, together with the observation that ( I ) is also formed on photolysis of phenylazirine, we conclude that it is formed by photochemical and not by thermal activation. This is thus the first case of intermolecular photocycloaddition t o a carbonnitrogen double bond. [3] Mercury high-pressure lamp: Philips HPK 125 W. 141 The NMR spectra were measured with a Varian A-60 apparatus for CC14 solutions with tetramethylsilane as internal standard. The synthesis of Ru~C15[P(n-C4H9)3]4 has been described recently and the results of chemical investigations suggest 111 the structure ( I ) . The complex has a magnetic moment of 0.75 B.M. per ruthenium atornI21 corresponding to one unpaired electron in the molecule. The dark red crystals are monoclinic, space group P21,'c with a = 13.866, b = 16.003, c = 30.545 A, p = 110.0". There are four molecules in the unit cell and the observed density gives a molecular weight of 1170.7 (theoretical 1188.8). The intensities were measured on a linear diffractometer [31 and the structure was determined by Patterson and Fourier methods.A least squares refinement of 3776 planes gives a current R-factor of 0.083. The standard deviations of the Ru-CI and Ru-P bond lengths are 0.0052 and 0.0054 8, respectively.+ 2 333 1 2 3 2 6The X-ray analysis confirms the structure ( I ) and the Ru-CI and Ru-P distances are shown in the figure. The coordination round the ruthenium atoms is approximately octahedral (the largest angular distortion is 12.4 ") and the environments of these atoms are very similar. The Ru....R...

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