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Autoxidation of Dimedone Derivatives.

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the aldiminium salt (2), with deprotonation. The expected
N,N-dimethyl-N-(2-indenylidenemethyl)amine(11) has not
yet been isolated as such, because of its low thermal stability.
Compound (If), which is yellow-brown in solution (UV
spectrum in CHzC12: Amax = 364, 376 nm) reacts with Nphenylmaleimide a t -40°C to give a colorless 1:l adduct
having m.p. 215-216OC. The UV spectrum (in n-hexane)
[Amax = 211 nm (E = 28000), 217 (26000). 223 (23200), 258
(loloo), 262 (9940), 267 (9000), 280 (3000). 286 (1lOO)l
corresponds t o that of an equimolar mixture of N,N-dimethylN-(2-indenylmethyl)amine and N-phenylsuccinimide, and so
points to the formation of a 1,3 adduct having the constitution (12a) or (12b); the N M R spectrum (in CDC13) of the
adduct [multiplets centered a t T = 2.55 (9 H), 5.80 (3 H), 6.64
(2 H), and a singlet at T = 7.68 (6 H)] is in agreement with a
mixture of epimers of ( I 2 b ) .
Received: January 26, 1968
[Z 716 IE]
German version: Angew. Chem. 80, 312 (1968)
1. For the preparation of N,N'-dimethylchloroformamidine
hydrochloride see reference 111.
2. N,N'-Dimethylchloroformamidine hydrochloride is refluxed for five hours with PC15 (molar ratio 1:l) in cc14.
The crude, slightly greenish product crystallizes out o n concentration of the reaction solution. Recrystallization from
anhydrous cyclohexane gives white crystals having m.p.
129 "C. The yield is almost quantitative.
Received: November 28, 1967 and February 12, 1968 12 717 IEI
German version: Angew. Chem. 80, 281 (1968)
[*] Dr. H. P. Latscha and P. B. Hormuth
Anorganisch-Chemisches Institut der Universitat
69 Heidelberg, Tiergartenstr. (Germany)
[l] H . Ulrich and A . A . R. Sayigh, Angew. Chem. 76,647 (1964);
Angew. Chem. internat. Edit. 3 , 585 (1964).
[2] H . P . Lafscha, Z . Naturforsch., in press.
[*] Prof. Dr. K. Hafner and Dip1.-Chem. W. Bauer
Institut fur Organische Chemie der Technischen Hochschule
61 Darmstadt, Schlossgartenstr. 2 (Germany)
[l] K . Hafner, K . H. Hafner, C. Konig, M. Kreuder, G. Ploss,
G. Schulz, E. Sturm, and K . H . Vopel, Angew. Chem. 75, 35
(1963); Angew. Chem. internat. Edit. 2, 123 (1963); K . Hafner,
K . H. Vopel, G. Ploss, and C. Konig, Liebigs Ann. Chem. 661, 52
(1963); K . Hafner, G . Schulz, and K . Wagner, Liebigs Ann. Chem.
678, 39 (1964); a quantum-chemical calculation of ( I ) has been
carried out by A . J. Sadlej, Acta phys. Polon. 27, 859 (1965).
[2] The compound ( 3 ) is based on 1,3-diphenyl-2H-indene,
whose 2,2-dimethyl derivative was prepared by K . Alder and
M . Fremery, Tetrahedron 14,190 (1961).
[3] K. Ziegler, K . Richter, and B. Schnell, Liebigs Ann. Chem.
443, 161 (1925).
[4] We are grateful to Dr. D . Jung for recording and discussing
the N M R spectra, and to Dr. N . Neuner-Jehle for the massspectroscopic examination of ( 3 ) .
[5] R . Kreher and J. Seubert, Angew. Chem. 78, 984 (1966); Angew. Chem. internat. Edit. 5, 967 (1966).
[6] R. Huisgen, Angew. Chem. 75, 742 (1963); Angew. Chem.
internat. Edit. 2, 633 (1963).
[7] R . Hofmann and R. B. Woodward, J. Amer. chem. SOC.87,
4388 (1965), and earlier communications.
181 Z . Arnold, Coll. czechoslov. chem. Commun. 30, 2783 (1965);
(10) can be isolated in a yield of about 50 % as an intermediate
in the Vilsmeier formylation of indene.
Autoxidation of Dimedone Derivatives
By H. Bredereck, R . Franz, and G. Bauer[*I
Hydroperoxides have until now been assumed t o occur as
intermediates in the initiation of the radical polymerization
of vinyl monomers by means of CH-active compounds,
atmospheric oxygen, C U ~ + and
CI-11-31. We have now
A and B = electron-withdrawing groups, R = H, alkyl
established their formation when dimedone derivatives are
used as CH-active compounds. Dimedone hydroperoxides
( 2 j were prepared for the first time by oxidation of dimedones
with oxygen in benzene at room temperature.
A Four-Membered Ring System Containing
Hexacoordinated Phosphorus
By H . P . Latscha and P. B. Hormuth[*I
The reaction of N,N'-dimethylurea with phosphorus pentachloride (PCIs) [I] in an inert solvent leads t o the formation
of a substance having the composition C ~ H ~ C I S N The
compound is white, very sensitive t o moisture, and melts at
129 O C after recrystallization from cyclohexane.
Reaction time
yield (%)
M.p. ( "C)
55 (decomp.)
81 (decomp.)
116 (decomp.)
90 (decomp.)
119 (decomp.)
The IH-NMR spectrum in benzene against T M S as internal
standard shows six equivalent methyl protons (8 = 2.67 ppm,
JPH= 20.8 Hz). The 31P-NMR spectrum contains a signal
The hydroperoxides form colorless crystals that cannot be
at 202 i 1 ppm (based o n 85 % H 3 P 0 4 as external standard),
stored for long periods. They were identified by elemental
JPH= 20 1 Hz. This indicates a phosphorus atom having a
analysis, iodometric titration, their reaction with lead tetracoordination number of 6 [21, and together with the elemental
acetate, and their I R and N M R spectra.
analysis, molecular weight, and 1R spectrum, points t o a
2,2,2,2,4-pentachloro-l,3-dimethyl-l,3-diaza-2-phosphonia~~The hydroperoxides that we have assumed to be formed
during polymerization can decompose either thermally or
-cyclobutanide ( I ) .
o n reaction with the cocatalysts Cu2+ and C1-13,41. For this
reason we were able t o isolate the hydroperoxides formed o n
autoxidation of dimedone derivatives only in the absence of
these cocatalysts. In the case of benzyldimedone, however,
we obtained the hydroperoxide also in the presence of Cuz'
and CI- because the extremely low solubility of the substance
caused its immediate precipitation.
Angew. Chem. internat. Edit. 1 VoI. 7 (1968) 1 No. 4
Procedure :
a) Reaction of the dimedone derivatives with R = CH3, CzHs,
i-C3H7. and i-C4H9: The dimedone derivatives (0.02 mole)
are dissolved in benzene (50 ml) and shaken with oxygen at
room temperature for 12-15 hours. The benzene is then
distilled off in a rotary evaporator and the residue is purified
by recrystallization from toluene or methanol.
b) Reaction of 2-benzyldimedone: 2-Benzyldimedone (0.03
mole) is suspended in benzene (50 ml) and, after addition of
copper(i1) acctylacetonate (1 mg) and lithium chloride (50mg),
the solution is shaken with oxygen at room temperature for
2 hours. The starting material gradually dissolves and the
hydroperoxide is obtained as a colorless flocculent precipitate
that may be recrystallized from methanol.
If a solution of hexacarbonylchromium and tris(trimethy1silyI)-, tris(trimethy1germanyl)-. or tris(trimethylstanny1)phosphine in tetrahydrofuran at room temperature is
irradiated for 5 hours with UV light 131. carbon monoxide is
evolved and the tris(organometa1o)phosphinepentacarbonylchromium(0) complexes (2) are formed.
(M = Si, Ge, Sn)
Received: February 21, 1968
[Z 723 IE]
German version: Angew. Chem. 80, 319 (1968)
H. Bredereck, Dr. R. Franz, and
Dip1.-Chem. G . Bauer
Institut fur Organische Chemie der Universitat
7 Stuttgart 1, Azenbergstr. 14-16
[l] H . Bredereek, B. Fohlisch, and R. Franz, Makromolekulare
Chem. 92, 70 (1966).
[2] H . Bredereck, B. Fohlisch, R. Franz, D . Tagoe, K . Diebel, and
B. Krurner, Makromolekulare Chem. 99, 96 (1966).
[3] H . Bredereck, R . Franz, and B. Kramer, Makromolekulare
Chem. 110, 12 (1967).
[4] H . Bredereck, A . Wagner, and K . Posselt, Chem. Ber. 93, 1284
[*] Prof. Dr.
Tris(organometalo)phosphine-pentacarbonylchromium and -dicarbonylnitrosylcobalt
By H. Schumann and 0. Stelzer[*J
The properties and reactions of organometal-substituted
phosphines suggested that the "lone" pair of electrons o n the
phosphorus atoms is involved in bonding by way of a
(p + d)n interaction between phosphorus and germanium,
tin, or lead 111. Tris(organometa1o)phosphines should therefore show little, if any, tendency to function as 0-donors in
transition metal complexes.
After having prepared organometalophosphinetricarbonylnickel(0) 121, we have now succeeded in synthesizing further
compounds containing coordinatively tetravalent phosphorus.
complexes ( I ) are obtained almost quantitatively when tricarbonylnitrosylcobalt is allowed to react with tris(trimethy1silyl)-, tris(trimethylgermany1)-, or tris(trimethylstanny1)phosphine in tetrahydrofuran at room temperature, with
stirring, for 24 hours. They are ruby-red substances that are
moderately soluble in benzene, tetrahydrofuran, and cyclohexane; they are diamagnetic and may be isoIated in a high
state of purity by sublimation at 80-100°C (10-5 torr). Like
the isostericorganometalophosphinetricarbonylnickel(0)complexes, they are stable toward atmospheric oxygen but by
way of contrast are found to have a higher thermal stability
than the former.
(CO),Co(NO) + [(CH3),M],P
+ CO
(M= Si, Ge, Sn)
On removal of the solvent in vacuum, yellow crystals are
obtained which sublime at 60-1OO0C (10-5 torr). With the
exception of the silicon compound, they are stable toward
atmospheric oxygen, and, like the analogous cobalt complexes, they have a relatively high thermal stability.
The coupling constants J[IHCM31P] of the complexes are
in some cases considerably greater than those of the free
organometalophosphines (M = Si: 4.62 Hz, Ge: 4.00 Hz,
Sn: 1.95 Hz). The IR spectrum of the chromium compounds
contains the three CO stretching vibrations required by C4,
symmetry; the vibrations are shifted only slightly toward
shorter wavelengths with increasing atomic weight of M
because the influence of the ligands is distributed over five
C O groupsr41. The I R spectrum of the cobalt complexes (1)
shows two CO stretching vibrations and one NO stretching
vibration. As the phosphine ligands increase in size, the CO
and the NO stretching vibrations are also displaced toward
lower wavenumbers. In addition to the internal vibrations
of the trimethylmetal groups, three further bands between
4000 and 280 cm-1 are t o be seen in the IR spectrum of the
Co complexes; we assign these to the vSPM3, vasPM3, and
the vP-Co vibrations. The I R spectrum of the chromium
compound contains two bands in this region, which correspond t o the v P M ~
and the vP-Cr vibrations.
Received: February 21, 1968
[Z 724 IEI
German version: Angew. Chem. 80, 318 (1968)
[*I Doz. Dr. H. Schumann and Dip].-Chem. 0. Stelzer
Institut fur Anorganische Chemie der Universitat
87 Wiirzburg, Rontgenring 11 (Germany)
[l] G . Engelhardt, P. Reich, and H. Schumann, Z . Naturforsch.
226, 352 (1967); H. Schumann, P. Jufzi, A . Roth, P. Schwabe, and
E. Schauer, J. organometallic Chem. 10, 71 (1967); H . Schumann
and A . Roth, ibid. 11, 125 (1968).
[2] H. Schumann and 0. Steizer, Angew. Chem. 79, 692 (1967);
Angew. Chem. internat. Edit. 6, 701 (1967).
[3] UV lamp: Q 81 Hanau.
[4] M. Bigorgne, J . organometallic Chem. 2, 68 (1964).
A New Cardenolide Synthesis
By H.-G. Lehmann and R . Wiechert [*I
When treated with alkali, 21-acyloxy-20-keto steroids ( I ) 111
undergo an intramolecular Wittig-Horner reaction t o form
cardenolides (2).
Thus we were able t o prepare 22-methyl-3-oxo-14ar-carda4,20(22)-dienolide ( 2 a ) (m.p. 243.5-245 OC, yield 51 %) by
heating a mixture of 1-(3,2O-dioxo-4-pregnen-21-yloxycarbony1)ethyltriphenylphosphonium bromide ( l a ) with one
equivalent of sodium hydride in dimethylsulfoxide, under
Angew. Chem. internat. Edit. I Vol. 7 (1968)
1 No. 4
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autoxidation, dimedone, derivatives
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