4-Azulenylacetic acid ( 4 ) (m. p. 122 T , de~omp.) '~] , prepared in 75 O h yield by reaction of 4-methyla~ulene[~~ with sodium N-methylanilide and subsequent carboxylation of the resulting sodium 4-methylenea~ulenide~'J, proved to be useful as starting material for the synthesis of (1 ). By treatment with sulfinylbis- (dimethylamine)f81 in benzene for 2 h at 60 'C ( 4 ) can be converted almost quantitatively into the carboxamide ( 5 ) . Cyclization in POCl3 (60-C, 2 h) yields 95 O/O of the ketimonium chloride (6) (perchlorate : red-brown crystals, m. p. 243 to 244 C, decomp.). Reduction of (6) by NaBH4 in methanol at 20 C followed by quaternization with methyl iodide affords the iodide (7) (yield 90%; blue-violet crystals, decomp. > 1 10 'C), and Hofmann degradation with 2~ NaOH at 20 'C finally gives rise to a 90% yield of the hydrocarbon ( I ) (brown leaflets having metallic luster, m. p. 69-70 'C, decomp.). Compound ( l ) is yellowish brown in solution and prone to autoxidation but thermally stable. The 60 MHz 'H-NMR spectrum of ( 1 ) (in CCI,), which pro- vides structural proof for the compound, contains a multiplet centered at T = 1.93 for the four protons of the seven-membered ring in addition to the signals of the two AB systems for the protons of the five-membered rings at r=3.18 and 2.54 ( J A ~ = 4 . 5 Hz). The electronic spectrum of ( I ) (in n-hexane) shows a pronounced vibrational structure in the UV and visible regions. Reduction of the quaternary salt (7) by NaBH4 in methanol at 0 'C yields I ,2-dihydrocyclopent[cd]azulene (8) (yield 37 YO; dark blue needles, m. p. 71 "C) which is isomeric to (2) and whose 2-0x0 derivative (9) is accessible by direct cyclization of ( 4 ) in acetic anhydride/pyridine (yield 83 %; red-brown crystals, m. p. 131--132^C). Oxidation of (9) with selenium

@ '.

dioxide in dioxane (60 'C, 3 h) affords cyclopent[cd]azulene- 1,2-dione (10) (10% yield, dark green needles, decomp. > 240 C), an isomer of acenaphthenequinone. Compound (3) was prepared similarly to ( 1 ) starting from 4,8-dimethyla~ulene'~~. 5-Methyl-l,2-dihydrocyclopent[cd]- azulene ( I I ) (blue needles, m. p. 132 "C) obtained analogously to (8) is converted into the carboxamide (12) (yield 95% ;blue rhomboids, m. p. 1 I5 C) which is cyclized to the tetracyclic ketimonium salt (13) (yield 45 %; perchlorate: red-brown

needles, decomp. > 270 C). Reduction (NaBH4) and quaterni- zation with methyl iodide finally yield the iodide ( 1 4 ) (air- sensitive blue powder). Treatment of ( 1 4 ) with potassium trrt-butoxide in tetrahydrofuran at - 20 T furnishes the highly strained, thermally unstable tetracyclic hydrocarbon (3) which is yellowish green in solution and could hitherto only been trapped as the cycloadduct ( 1 5 ) (dark green crystals, m. p. 108°C) by reaction with dimethyl acetylenedicarboxylate at 0°C. Reduction of (14) by lithium tetrahydridoaluminate in ether a t 20°C affords 1,2,4,5-tetrahydrodicyclopent[cd,ij]- azulene (16) as pale blue needles (m.p. 180°C, decomp.; yield 85%).

Received: December 27. 1973 [ Z 976 IE] German version: Angew. Chem. 86, 235 (1974)

[ I ] K . Hafner and J . Schnrider, Liebigs Ann. Chem. 624, 37 (1959); K . Hafner and K . F. Bangert, ihid. 650, 98 (1961): K . Hafner, Angew. Chem. 75, 1041 (1963): Angew. Chem. intcrnat. Edit. 3, 165 (1964): K . Hafnrr, Pure Appl. Chem. 28, 153 (1971). [2] K . Hafnrr and R. Flrischer, Angew. Chem. 82,217 (1970): Angew. Chem. internat. Edit. 9, 247 (1970); K. Hafner and W Rieper, Angew. Chem. 82, 218 (1970); Angew. Chem. internat. Edit. 9, 248 (1970). [3] L. A. Puquette, R. A. Wingard, J r , and R. K . Russell, J. Amer. Chcm. SOC. 94, 4739 (1972): G. P. Ceasar, J . Green, L. A. Paquettc,. and R . E. Wingard. Jr . , Tetrahedron Lett. 1973, 1721. [4] E. Vogrl, U . H. Brinker, K . Nachtkamp, J . Wassen, and K . Mul len, Angew. Chern. 85, 760 (1973); Angew. Chern. internat. Edit. 12, 758 (1973). [5] The structures of the products described were confirmed by elemental analysis, and UV, NMR, and M S spectra. [6] K. Hafner and H. Mddes, Liebigs Ann. Chem. 606. 90 (1957). 171 Cf. K . Hafner, H. Pelster, and H. Parzelr, Liebigs Ann. Chem. 650, 80 (1961). [S] G. Rosini, G . Baccolini, and S . Cucchi, Farmaco, Ed. Sci. 26, 153 (1971).

An Aza[l3]- and an Aza[ 17]annuIenyl Anion[ ' ] [**]

By Gerhard Schroder, Giinter Frank, Herbert Rottele, and Jean F. M. Othr'] The pyrrolyl or aza[5]annulenyl anion has long been known and possesses considerable interest from both a theoretical and a preparative standpoint[''. The synthesis and properties of the azoninyl or all-cis-aza[9]annulenyl anion have recently been described"! We now wish to report an aza[13]- (2) and an aza[ 17]annulenyl anion ( 5 ) .

("c3 p: COOCvHx

I..

( I ) , t w o isomers L 4 '

Photolysis of the adduct of ethoxycarbonylnitrene to the dou- ble bond of the four-membered ring in tricycl0[6.4.0.0~~~ ']do- deca-2,4,6,10-tetraene at - 70°C affords two isomeric N -

[*] Prof. Dr. G Schroder, DipLChem. G. Frank, and Dr. H. Rottele Institut fur Organische Chemie der UniversitPt 75 Karlsruhe, Richard-Willstatter-AIlee (Germany) Prof. Dr. J . F. M. 0 t h Organisch-Chemisches Laboratorium der ETH Zurich (Switzerland)

[**I We are grateful to Badische Anilin- & Soda-Fabrik AG, Ludwigshafen, for a gift of cyclooctattrtraene.

Anyew. Chem. internat. Edit. 1 Vol. 13 11974) No. 3 205

ethoxycarbonylaza[l3]annulenes (1) [41. Photolysis of the addition product of ethoxycarbonylnitrene to tricyclo- [8.6.O.O2v9] hexadeca-3,5,7,11,13,15-hexaene leads to three iso- meric N-ethoxycarbonylaza[ 17lannulenes (4) ['I. Treatment of the azaannulenes ( I ) and ( 4 ) respectively with potassium tert-butoxide in T H F at 0°C alway furnishes the same aza[ 133- and am[ 17lannulenyl anions, according to NMR spectroscopic evidence. On the basis of the NMR spectra (see Table 1) and double resonance experiments considering in particular the number of inner and outer protons, the characteristic absorptions of the protons in (x and p position to the nitrogen, and the coupling constants, these anions must be assigned the configurations (2) and (5)I6] respectively. The following three points warrant attention: 1) The configurationally isomeric azaannulene ( I ) or ( 4 ) gives rise to only one azaannulenyl anion, (2) or (5). We thus conclude that the aza[ 131- and the am[ 17]annulenyl anions must be configurationally labile. 2) The nonbonding electron pair on the nitrogen of (2) and ( 5 ) is directed towards the center of the ring. Taking account of the statements made under 1, we deduce that the spatial requirement of a hydrogen on the sp' C atom is greater than that of the lone pair of the sp' N atom. 3) The difference between the resonance signals for the inner and outer protons is ca. 10ppm for (2) and ca. 14ppm for (5) . These values indicate that the magnetic field induces a considerable diamagnetic ring current in these species. Protonation of (2) and (5) with water-saturated ether contain- ing a small amount of acetic acid yields crystals of am[ 131- (3) and aza[17]annulene (61, respectively, which decompose on attempted melting-point determination. The compounds were purified by column chromatography [(3): AI2O3 (basic);

Cpd. Yield 'H-NMR, 7 [ppm] [a] "'01

(2 ) red-brown

( 3 ) yellow

( 5 ) blue-green

( 6 1 red

= 100 [b]

.= 80 [b]

22 100 [c]

.= 60 [c]

0.45 (la-H/d; J = 7 Hz), 0.58 (la-H/d; J=7.5 Hz), 1.90 (4H/m), 2.60 ( I H/t ; J = 9 Hz), 2.72(lH/t . J=10.5Hz), 3.08 ( I P-H/t; J = 7 Hz), 3.24 (I P-H/dd, J=7.5/10.5Hz). 12.27 ( lH/ t ; J=13.5Hz), 13.05 ( I H/t; J = 14Hz) 2.72 (I z-H/d: J = 8.5 Hz),

4.34 ( I P-H/dd; J = 6.5/8.5 Hz), 4.55 (IP-HIt: J=8.5Hz), 7.20 ( I N-H/br. s), 7.71 ( IH/ t . J=13Hz) , 7.99(IH/dd: J=11/17.5Hz) -0.35 (Zx-H/two d ; J=6/7Hz), 0.5-1.1 (7H/m), 1.40 I I a-H (l6-H)/d.d: J=6/13 Hz), 2 . 0 5 ( l H (10-H/t; J=lOHz), 2.70 (IP-H (3-H)/d,d: J=7/10Hz). 14.9 (4H/four t ; J = 13Hz) 2.2-3.0 (9H/m) [d], 3.25 ( I P-H/d,d; J = 8 / l 1 Hz), 3.45 (lP-H/d,d; J=8/13Hz), 4.24 ( I H (10-H)/t: J=8.5Hz), 7.55(1H/t; J = 13Hz), 7.98 (I H/d,d; J = 10.5/14.5Hz), 8.5 (3 H/m, one of which is I H N-H, see text)

2.8-3.8 (7 H/m),

-

[a] 100 and 60 MHz spectra, (2) and ( 5 ) in THF, ( 3 ) and (6) in C S 2 ; <a. 25 C; TMS as standard. [b] Based on ( I ). [c] Based on ( 4 ) . [d] The two r* protons appear as two doublets at 7 = 1.95 in D8-THF at -60 C.

(6): S i 0 2 (pentane/ether 95: 5 ) ] ; they are highly sensitive to oxygen. The configurations ( 3 ) and (6) are unequivocally confirmed by NMR data (see Table 1) and by the following experiment: If a solution of ( 3 ) or (6) in CS2 is shaken with D,O in a NMR sample tube, the intensities of the upfield signals a t t = 7.20 and 8.5 respectively are each reduced by about 1 H. We assign the upfield signals in the 'H-NMR spectrum of (3) and (6) to the inner protons, and the downfield signals to the outer protons. The difference in the center of gravity of these signals amounts to ca. 4.7 ppm for ( 3 ) and ca. 5 ppm for (6). The induced diamagnetic ring current is now con- siderably smaller than in (2) and (S) , but, unlike that in (1)14] and (4) [ ' ] , it is however still readily detectable. This finding accords with previous results for aza[9]ann~lenes'~l.

Received: January 2, 1974 [Z 978 IE] German version: Angew. Chem. 86, 237 (1974)

[ I ] Annulenes, Part 22.-Part 21: G . Schroder, G . Kirsch, and J. F . M . Orh, Chem. Ber. 107, 460 (1974). [2] See, e.g., M . H . Palmer: The Structure and Reactions of Heterocyclic Compounds. E. Arnold, London 1967. [3] A. G. Anastassiou, Accounts Chem. Res. 5 , 281 (1972): A. G . Anastassiorr and S. W Eachus, J. Amer. Chem. SOC. 94, 2537 (1972): R. T Seidner and S. Masamune, J. C. S. Chem. Comm. 1972, 149. [4] G. Srhroder, G. Frank, and J. F. M . 0 t h . Angew. Chem. 85, 353 (1973): Angew. Chem. internat. Edit. 12, 328 (1973). [ S ] G. Schrodcr, G. Heil, H . Riittele, and J. F. M . Oth, Angew. Chem. 84, 474 (1972): Angew. Chem. internat. Edit. 1 1 , 426 (1972). [6] We cannot rule out a positional isomer of ( 5 ) in which the nitrogen shows up at position 5 (retaining the numbering given in ( 5 ) ) .

A Simple Synthesis of 3(5)-Aminopyrazole[**]

By Giinter Eye and Philipp Arnold['] Dedicated to Professor Hans Plieninger on the occasion of his 60th birthday

3(5)-Aminopyrazole has formerly been accessible only by way of multistage syntheses" - '1. We now report a one-stage prep- aration of 3(5)-aminopyrazole (2) utilizing commercially available starting materials and giving 70% yields of the pure product. The reaction involves addition of aqueous hydra- zine solution to 2-chloroacrylonitrile in alkaline solution (potassium carbonate).

lN$NH]

H H - N$$NH2 H

HA HB

(3)

[*] Prof. Dr. G. Ege and P. Arnold Organisch-Chemisches Institut der Universitat 69 Heidelberg, Im Neuenheimer Feld 7 (Germany)

[**I This work was supported by the Deutsche Forschungsgemeinschaft and the Fonds der Chemischen Industrie.

206 Angew. Chem. internat. Edit. / Vol. 13 (1974) / No. 3