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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 isomeric 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 containing 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][**I This work was supported by the Deutsche Forschungsgemeinschaft.We are indebted to BASF, Ludwigshafen, for a gift of cyclooctatetraene, and to Miss G. Sckneidc,r for assisting with the kinetic measurements.

Im Rahmen unserer Untersuchungen der Fragmentierung heterocyclischer Verbindungen 1b) interessierten wir uns fur die Frage, ob in cyclischen Verbindungen an die Stelle einer Kohlendioxidabspaltung auch eine solche von Kohlenoxidsulfid treten kann. In einer derartigen Analogiereaktion diirfte jedoch die Abspaltung von Kohlenoxidsulfid weit weniger begunstigt sein als die entsprechende von Kohlendioxid, da die Bindungsenergie der C=S-Bindung (128 kcal -mol-1 = 536 kJ.mo1-1) im Kohlenoxidsulfid wesentlich geringer ist als die der C =0-Bindung (192 kcal . mol-1 = 803 kJ -mol-1) im Kohlendioxidz).Fur das Studium einer Fragmentierungsreaktion unter Kohlenoxidsulfid-Eliminierung erschien uns das in der Literatur als ,,Phenanthro[9,1O-e]-l,2,4-oxadiazin-2-thion' G (lpe) und das als ,,Acenaphtho[l,2-e]-1,3,4-oxadiazin-2-thion6c

S-Kalium-((W-organy1hydrazino)monothio-und Kalium-[(W-organylhydrazino)dithioformiate]1 A bzw. 1 B lassen sich mit a-Halogenketonen am Mercapto-Schwefel zu rein isolierbaren (Hydrazino)thioameisensaure-acylmethylestern 2 A bzw. 2 B oder deren cyclischen Derivaten 2' A bzw. 2' B alkylieren. Diese ergeben in saurer Losung 3-Organylamino-l,3-thiazolin-2-one 3 A bzw. -2-thione 3B. Der Beweis fur das Vorliegen der funfgliedrigen Ringstruktur wurde durch chemische Reaktionen und UV-spektroskopisch erbracht. Die syn-anti-diastereomeren Dithiokohlensaure-S.S' -dialkylester-tosylhydrazone 2-5 und E-5 wurden hergestellt und zugeordnet.Five-Membered Heterocycles, VI I). -3-Organylamino-1,3-thiazolin-2-ones and -2-thiones S-Potassium (A"-organy1hydrazino)monothio-and potassium (A"-0rganylhydrazino)dithioformates 1 A and 1 B are alkylated at the mercapto sulfur atom with a-halo ketones to form the acylmethyl (hydrazino)thioformates LA and 2B, which can be obtained pure, or their cyclic derivatives 2 ' A and 2'B, respectively. In acidic solution these products are transformed into 3-organylamino-l.3-thiazolin-2-ones 3 A or -2-thiones 3B, respectively. Proof for the five-membered ring structure comes from chemical reactions and UV spectroscopy. The syn-anri-diastereomeric S,S'-dialkyl dithiocarbonate tosylhydrazones 2-5 and E-5 have been prepared and their stereochemistry assigned.Im Rahmen unserer Untersuchungen der Fragmentierung heterocyclischer Azoverbindungen2) interessierten wir uns fiir die Darstellung von 4-Tosyl-3,4-dihydro-I ,3,4-thiadiazin-2-onen I A, urn aus diesen durch Eliminierung von p-Toluolsulfinat cyclische Azoverbindungen vom Typ des 1,3,4-Thiadiazin-2-ons 11A her~ustellen~).