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Thermal Dehydrogenation of C C-Dialkyldiazacyclopropanes.

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Atomic models indicate that replacement of the two internal
hydrogen atoms in ( I ) by a methylene group should result
in the formation of an almost, if not completely planar structure of the cyclodecapentaene skeleton.
The synthesis of 1,6-methanocyclodecapentaene(2) [or of
(5)] started from 1,4,5,8-tetrahydronaphthatene[2]. The
triene adds on dichlorocarbene (generated from CHCI3 and
K-t.-butoxide) at the central double bond with a high degree
of selectivity [3] affording (S), m.p. 83-84°C. Sodium in
liquid ammonia converts (3) into ( 4 ) , b.p. 80-81 .C/ll mm,
and this reacts with bromine in the cold to form a tetrabromide,
m.p. 128-129 "C. This compound reacts with bases, e.g. alcoholic KOH, to give a good yield of the desired hydrocarbon
C l l H l o as colorless crystals, m.p. 28-29 "C.
:3/
141
(5)
Three structures of the hydrocarbon are possible: a) ( 5 ) ;
b) (2) with a fluctuating structure according to (6) $
(5) ;" (7); and c) (2) with a delocalized Tc-electron system
[(6) (8)I.
m-+pJ==
-
ihl
i8)
( 7)
The ultraviolet spectrum of the hydrocarbon has maxima
at 256my (E = 68000),2 5 9 m y (E = 63000), and 298my
(E = 6200); this suggests an extensive conjugated system [not
compatible with (5)]. The N M R spectrum is particularly
revealing: it shows an AzBz system (8 protons) in the range
2.5-3.2 5 , centred at 2 . 8 r , and a sharp signal at 10.5 T
(2 protons). The absorption of the olefinic protons at very low
field, combined with strong shielding of the CHz-protons
above the peripheral ten-membered ring, can be considered
as evidence [4]for the presence of a ring current and, therefore, for the 1,6-methanocyclodecapentaenestructure (6) to
(8) [ 5 ] . I ,6-Methanocyclodecapentaene is highly strained,
however, and is certainly not an aromatic compound in the
classical sense, because it exhibits olefinic reactivity just like
the [ I 81- and [30]annulenes [6].
Received, January Znd, 1964
[Z 638/464 IE]
German version: Angew. Chem. 76, 145 (1964)
..
Rearrangements of p-quinols i n trifluoroacetic anhydride
yield the same products. The p-quinolide compound is
dissolved in trifluoroacetic anhydride at room temperature
and, after some time, the reagent is evaporated. On short
hydrolysis with dioxan/water, the phenolic products of rearrangement are usually obtained in quantitative yield and in
pure form. Some of the labile trifluoroacetates of the phenolic
products of rearrangement can be isolated before hydrolysis.
.~
[I] 7'.J . K a / r , J . Amer. chem. SOC.82, 3784 (1960); T . J . Katr
and P . J . Gnrrarr, ibid. 85,2852 (1963), and E. .4. LaLancette and
R . E. Benson, ibid. 85, 2853 (1963) described negatively charged
10-n-electron carbocycles with aromatic character, v i t . the cyclooctatetraene dianion and the cyclononatetraenyl anion.
[2] W. HiickeJ and H . Schlee, Chem. Ber. 88, 346 (1955).
[3] E. Vogel, W. Wiedemann, H. Kiefer, and W. F. Harrison,
Tetrahedron Letters 11, 673 (1963).
[4] L. M . Jackman, F. Sondheimer, Y . Amiel, D . A. Ben-Efrnim,
Y . Gnoni, R . Wolovsky, and A . A . Bothner-By, J. Amer. chem.
SOC.84, 4307 (1962).
[5] A fluctuating structure seems unlikely in view of the position
ofthe olefinic protons in theNMR spectrum; however, it remains
a possibility.
161 F. Sondheimer, R . Wolovsky, and Y. Amiel, J. Amer. chem. SOC.
84, 274 (1962).
p-Toluquinol ( I ) yields toluhydroquinone (2) and cresorcinol (3), but rearrangement of the methyl and tetrahydropyranyl ethers of p-toluquinol yields only the hydroquinone
and no resorcinol derivative. Tetralin-p-quinol (4) and its
ethers rearrange exclusively to 5,8-dihydroxytetralin (5) or its
monoethers, with 1,3-migration of the alkyl substituent. The
acetates and benzoates of p-toluquinol and tetralin-p-quinol
are converted exclusively into the monoesters of the corresponding resorcinol derivatives.
The rearrangements can be explained by assuming that
even a t room temperature trifluoroacetic anhydride contains a sufficient concentration of CF3CO" ions to cause
electrophilic attack on the carbonyl group of the dienone
system and thereby to initiate anionic migration of substituents and consequent aromatization. With p-quinols and
their ethers, the alkyl group migrates preferentially; with
quinol esters, the acyl group migrates considerably faster
than the alkyl group. The exceptional behavior of p-toluquinol (and other monocyclic p-quinols) can be explained
by assuming that esterification of the hydroxyl group competes with the migration of the alkyl group, and that subsequent rapid migration of the attached trifluoroacetyl group
occurs. The high rate of esterification [2] of p-toluquinol and
the small rate of migration of the alkyl group can be established by kinetic measurements [3].
Received, January Znd, 1964
[ Z 640/478 IE]
German version: Angew. Chem. 76, 221 (1964)
[ I ] E. Hei.ker and S . M . A. D. Zajed, Hoppe-Seylers Z . physiol.
Chem. 325: 209 (1961); cf. Angew. Chem. 71, 744 (1959); E.
Hrcker and F. Marks, Naturwissenscharten 50, 304 (1963).
[2] E. Hrtker a n d R. Lattrell. Chem. Bcr. 96, 639 (1963).
[3] E. Hecker and E. M e p r , Chem. Ber., in the press.
Thermal Dehydrogenation of
C,C-Dialkyldiazacyclopropanes
By Dr. A. Jankowski and Dr. S. R. Paulsen
Bergbau-Forschung GmbH., Forschungsinstitut des
Steinkohlenbergbauvereins, Essen-Kray (Germany)
Rearrangements of p-Quinols in
Trifluoroacetic Anhydride
By Doz. Dr. E. Hecker and E. Meyer
Max-Planck-lnstitut fur Biochemie, Miinchen (Germany)
C,C-Dialkyldiazacyclopropanes ( I ) are dehydrogenated by
oxidizing agents (yellow mercuric oxide, permanganate,
chromic acid) to give C,C-dialkyldiazacyclopropenes (2)
t1,21.
p-Alkylphenols of biochemical importance are oxidized
during intermediary metabolism to p-quinols [I], which
rearrange to alkylhydroquinones under the influence of
enzymes.
Angcw. Cliein. interiiat. Edit.
Vol. 3 (1964) / No. 3
229
We have found that compounds of type ( I ) can also be dehydrogenated to (2) simply by heating to 125 ' C . In addition
to (21,ammonia and a high molecular-weight nitrogenous
residue are formed.
On addition of Cu(1) or Cu(l1) salts to solvent-free ( I ) ,
strongly exothermic dehydrogenation starts, according to
the type of the groups R, either spontaneously at room
temperature or o n warming to 60 "C. In the presence of water
and copper or copper salts, 1 mole of (1) is converted in
96.5 % yield into 0.5 mole of (2), 1 mole of NH3, and 0.5
mole of a ketone with the same carbon skeleton as ( I ) .
The products were separated by distillation and identified by
infrared spectroscopy, gas chromatography, and refractive
indices.
We assume that in this reaction 1 molecule of ( 1 ) is dehydrogenated by a second molecule of ( I ) , giving rise to
(2) and the C,C-dianiino compound ( 3 ) . The latter condenses to high molecular-weight compounds with loss of
Table I. Examples o f the reaction 12) + ( 5 j
-___
Yield of
f 5 i [ %I
I00
M. p.
[ 'Cl
199
72
238
24 I
224
275
210
I80
73
82
100
89
1 no
I00
98
Starting with. aminoanthracene or aromatic diamines, we
obtained more highly condensed ring systems.
Received, January Znd, 1964
[ Z 6481475 IE]
German version: Angew. Chem. 76, 188 (1964)
~
[ I ] U.S. Pat. 2768 174 (Oct. 23rd, 1956) Societe des usines chimiques Rhbne-Poulenc, inventors : R . E. Poul and S. Tchelitehef;
Chem. Abstr. 51, 5818 (1957).
Inversion of the Triphenylamine Molecule
ammonia or, in the presence of water, is hydrolysed to the
ketone and ammonia.
[ Z 655/480 IE]
Received, January 3rd and 29th, 1964
German version: Angew. Chem. 76, 229 (1964)
~
~
-~
[I] S. R. Poi//sen, Angew. Chem. 72, 781 (1960).
[2] E. Schrnitz and R. Ohme, Chem. Ber. 94, 2166 (1961).
Syntheses with (3-Alkoxyacrylyl Chlorides
By Dr. F. Effenberger and Dipl.-Chem. W. Hartmann
Institut fur Organische Chemie und Organisch-Chemische
Technologie der Technischen Hochschule Stuttgart (Germany)
The interaction of P-alkoxyacrylyl chlorides ( I ) [I] with
alcohols, phenols, thiophenols, hydrazines, and amines has
afforded new derivatives of P-alkoxyacrylic acids, some of
which are suitable for the synthesis of otherwise difficultly
accessible heterocyclic compounds.
By Dip1.-Phys. P. Knobloch and Dipl.-Phys. M. Stockhausen
Physikalisches Institut der Uiiiversitat Mainz (Germany)
Conclusions can be drawn from the relaxation time of
dipole orientation in dilute solution about the mechanism by
which the electrical moment of a polar molecule orientates
in the applied electrical field. Moments that are rigidly incorporated into the molecule can only orientate by rotation
of the whole molecule, resulting in a relatively long relaxation
time. However, if intramolecular adjustment can occur
making more rapid dipole orientation possible, without the
whole molecule having to move, the relaxation time is less.
Table I. Relaxation times 7 of the dipole orientation and dipole
moments $ of triaryl derivatives of Group V elements in benzene.
1
Compound
7
[sec]
77,IO '2
60' 10-'2
0.7 I l0-12 (approx.)
70 1 0 - 1 2
Triphenylarsine
Triphenylphosphine
Triphenylamine
Tribenzylamine
I I* [Debye]
1.18
1.52
0.66
0.7
40
R' - o - c H=y - C,
~2
When the anilides (2) are ground with concentrated mineral
acids, carbostyrils ( 5 ) are obtained smoothly within a few
minutes in good yields. Table I gives a list of examples.
The action of concentrated acids on the naphthalides ( 3 )
gave benzoquinolones ( 6 ) [R2 = H, m.p. 257'C, 100%
yield; Rz = CH3, m. p. 240"C, 95 "/, yield] and o n the
phenylhydrazides ( 4 ) gave 1-phenylpyrazol-3-ones ( 7 )
[R2 = H , m.p. 153 " C , 98 ?< yield].
230
NH -NH- CGH,
Our relaxation measurements [ 13 yielded direct information
about the different modes of behavior of triphenylamine and
the triaryl derivatives of the higher elements of Group V.
Results obtained for solutions in benzene are shown in
Table 1 .
Relaxation times of the magnitude shown for the first two
substances in Table 1 were to be expected, in view of the
rotatory orientation of the entire molecule. This could be
Angew. Chem. infernot. Edit. / Vol. 3 (1964)
/ No. 3
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