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1 1 -Bis(trimethylsilyl)tetrazadiene.

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which can also be synthetized by butylaminolysis of arsenic
trichloride in benzene.
4 AS13
+ 14 C4HgNH2
-+
As4(NC4H&
+ 12 C ~ H ~ N H Y H C I .
This compound, which is sensitive to air, is a yellowish oil,
b.p. 195-200°C in vacuo, n$2 = 1.5379, is a homologue of
As4(NCH3)6 [2], and has a urotropine-type structure.
Received, October 29tb, 1962
[Z 379/203
The structure proposed for (2) is rendered probable by the
method of its synthesis and by its infrared spectrum
(v N = N = N : 2130 cm-1, 1290 cm-1; vas N-N=N:? 1260
\ -N-N=N=NQ
-e-
/
(CH3hSi
IE]
[I] G. Kamai and Z , L. Khisamova, Doklady Akad. Nauk SSSR
-
-(CH~)JS~
'N-CI
/
+ LiN3
-.+
-1.1c1
(CH~IS~
(CH33Si
(CHhSi
105, 489 (1955).
(CH3hSi
(1)
[2] H. Ndth and H . J. Vetter, Naturwissenschaften48,553 (1961).
-
1
\el--N=N-N=N@
.-
/
-
a
(2)
b
-
l,l-Bis(trimethylsilyl)tetrazadiene [11
By Dr. Nils Wiberg and cand. chem. A. Gieren
Institut fur Anorganische Chemie
der Universitat Miinchen (Germany)
Treatment of 2-chloro- 1,1,1,3,3,3 - hexamethyldisilazane,
excess lithium azide in tetra[ ( C H ~ ) ~ S ~ ~ Z(I),
N - Cwith
~
hydrofuran at room temperature for two days leads almost
quantitatively (based on the quantity of lithium chloride
formed) to I, 1-bis(trimethylsily1)tetrazadiene (or 2-azido1,1,1,3,3,3-hexamethyldisilazane)(2), a colorless liquid of
b.p. 40-42 OC/ll mm Hg.
Compound (I) can easily be prepared by chlorination of
the N-sodium saIt of hexamethyldisilazanein ether at-50 "C.
It is a yellow-green, photosensitive, mobile liquid (b.p.
41-43 " C / l l mm) decomposing slowly at 100°C.
[l] Contributions to the Chemistry of Silicon: 3rd Communication. - 2nd Communication: Angew. Chem. internat. Edit. 1,
551 (1962).
[2] The formula shows only two of the many possible mesomeric
structures.
[3] The tetrazadienes ON4 [H. W. Lucien, J. Amer. chem. SOC.
80,4458 (1958)l and (CH3)zNd [I€. Bock and K. Kompa, Angew.
Chem. internat. Edit. I, 264 (1962)l have similar structures but
are less stable.
CONFERENCE REPORTS
Second International Symposium on the Chemistry of Natural Products
This symposium - excellently organized in every respect took place from August 27th through September 2nd in
Prague. It was arranged by the Czechoslovakian Academy of
Sciences, the Czechoslovakian Chemical Society, and the
International Union for Pure and Applied Chemistry. The
main theme was the chemistry of steroids, terpenes, and
alkaloids.
1.7)
(3)
C1
F r o m t h e P r o ce e d.i n gs :
Plenary Sessions
R. B. Woodward (U.S.A.) reported on the total synthesis of
(f)-6-demethyl-6-deoxytetracycline(I). The synthesis starts
from methyl o-methoxybenzoate and proceeds in four
steps to the dicarboxylic acid (2). After chlorination of the
aromatic ring with Clz/acetic acid at 15 "C, ring C may be
closed with liquid H F at 15°C to give (3). Heating the
methyl ester of (3) with dimethyl oxalate and sodium
methoxide yields ( 4 ) ; the latter is decarboxylated and then
heated with n-butyl glyoxylate in toluene for 1 hour in the
presence of magnesium methoxide. The condensation product
664
obtained is treated with dimethylamine at -10 ' C , giving (5),
which loses its methylamino group readily. In order to
stabilize this compound, the carbonyl group of ring B has to
be reduced with NaBH4 at -7O'C.
(7)
Five further steps lead to (6). When this compound is heated
with NaH/dimethylformamide and a trace of methanol at
Angew. Chem. internat. Edit.
VoI. I (1962) / No. I2
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