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An Optically Active Derivative of Methylenetribenzocycloheptatriene.

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The reactions are carried out in liquid ammonia, in which the
majority of the alkali phosphides MPH2 and MPHR dissolve
without decomposition owing to the difference in pK, between phosphine and ammonia 13). The alkali phosphides are
prepared in liquid ammonia from sodium or potassium and
PH3 141 or a primary phosphine (color change to yellow). The
sodium salt of the halogenocarboxylic acid is then simply
added to the solution.
The carboxylic acids ( 1 ) - ( 4 ) are colorless liquids with a characteristic odor; they decompose in air but can be distilled
unchanged in vacuo and form colorless crystals slightly below
room temperature. Vacuum distillation of (5)-(8) is not recommended. Compounds (1)-(4) dissolve in ether and in
water with an acidic reaction, but (5)-(8) dissolve in organic
solvents only. Polarographic studies revealed that ( 1 ) - ( 8 )
have a partially zwitterionic structure. Almost quantitative
yields of the corresponding methyi esters (seeTable) are obtained from (I)-(4) with diazomethane in ether; the esters
are colorless, low-boiling liquids which ignite spontaneously
when finely divided in air. Analogous derivatives are obtained
from (5)-(8). The phosphine portions of (1)-(8) can be
quaternized with hydrogen iodide.
Received: January 4th, 1965
[ Z 8891712 IE]
German version: Angew. Chem. 77, 172 (1965)
[ I ] Alkali-Phosphorus Compounds and their Reactions, Part
34. - Part 3 3 : K. Isskib and L. Brusehaber, Z. Naturforsch., in
the press.
121 K . Issleib and G.Thomas, Chem. Ber. 93, 803 (1960).
131 K . Issleib and R. Kiimmel, J. organometal. Chem., in the
[4] R. J. Wagner and A . B. Burg, J. Arner. chem. SOC.75, 3869
[ 5 ] A. R . Stiles, F. F. Rust, and M . E. Vaughan, U.S.-Patent
2803597 (1957); Chem. Abstr. 52, 2049b (1958).
ation [2] of tribenzocycloheptatrienone (yield: 75 %) and
treated it with lithium in dimethoxymethane [3] at -20 to
--25 "C t o form the lithio compound ( f b ) . Carboxylation of
( I b ) and subsequent hydrolysis produced a 60% yield of 1-
m.p. 249--251 "C. The structure of ( I c ) was proved by its
(lb), X
elemental analysis, molecular weight, N M R , ultraviolet,
and infrared spectra, and by its oxidation with potassium
permanganate to tribenzocycloheptatrienone.
The carboxylic acid (fc) was resolved vicr its brucine salt into
its optical antipodes, which were quite stable and exhibited
specific rotations ([u]& = t31.7 and [a]:& = -~30.9 ', c =
0.026 g/cm3 in acetone) which were strongly dependent on the
solvent used. N o loss of the optical activity was observed
even o n prolonged standing of solutions of the optical antipodes at room temperature[*].
Racemization of the optical isomers in diethylene glycol dimethyl ether at 139 "C showed that the rotations decrease by
a first order mechanism with kexp = 1.1 x 10-4 sec-1 o n the
average. Thus, since kinversion = 0.5 kexp [41, a free energy
of activation AFS = 3 I kcal/mole is calculated for the inversion at 139 "C. Thus racemization caused by inversion of the
seven-membered ring appears to proceed somewhat slower
than the racemization of bromodibenzocyclooctatetraenedtcarboxylic acid 151.
Received: January 4th. 1965
[Z 888/711 IE]
German version: Angew. Chem. 77, 173 (1965)
__ -_ [ * ] Note added in proof: Two optically active derivatives of
methylenedibenzocycloheptatriene were recently described by
A . Ebnother, E. Jucker, and A . Stoll, Chimia 18, 404 (1964).
[ I J W. Tochtermann, U.Walter, and A . Mannschreck, Tetrahedron Letters 1964, 2981.
[2] G. Kubrich, Angew. Chem. 74, 33 (1962); Angew. Chem.
internat. Edit. I, 51 (1962). We wish to thank Dr. Kobrich for
supplying a sample of bromomethyltriphenylphosphonrum
131 U. Srhollkopf' and H . Kiippers, Tetrahedron Letters 1964,
An Optically Active Derivative of
By Dr. W. Tochtermann and Dr. H. Kuppers
Organisch-Chemisches lnstitut der Universitat Heidelberg
Inversion of the seven-membered ring occurring in the nonplanar boat form is more difficult in di- and tribenzocycloheptatrienone acetals than in cycloheptatriene [I]. Suitable
substituted tribenzocycloheptalrienederivatives ought theryfore to be separable into optically active antipodes.
To test this prediction, we prepared bromomethylenetribenzocycloheptatriene(lcr), m. p.l27-- 129 OC, by bromomethylen-
[4] R . Huisgen in Houben- W e y l : Methoden der organischen
Chemie. Thieme, Stuttgart 1955, Vol. III/I, p. 99; A. A . Frost
and R. G. Pearson: Kinetics and Mechanism. Wiley, New York
1961, pp. 99, 186, 373.
[5] K . Mislow and H . D . Perlmutter. J. Amer. chem. SOC.84,
3591 (1962).
Therapy Congress and Pharmaceutical Exhibition
The lectures delivered at the 16th German Therapy Congress,
which took place in Karlsruhe (Germany) from August 30th
to September 5th, 1964, dealt inter alia with the therapy of
liver and bile-passage ailments, the treatment of thyroid
disorders, the application of tissue extracts, the treatment of
cardiac and circulatory diseases, the therapy and prophylaxis
of thromboembolic illnesses, and physical therapy during
convalescence. - A seminar lasting several days was heid
to discuss disorders of the water-electrolyte balance as an
adverse factor influencing therapeutic treatments.
The exhibition of pharmaceuticals had products from about
250 companies o n display. Of the many new preparations in-
troduced, only those which contain hitherto unknown
chemical compounds or substances which are appearing for
the first time o n the German market are listed in the following report.
A new oral antidiabetic, Redula', was developed jointly by
Farbenfabriken Bayer and Schering AG. Its ingredient does
not belong to the sulfonylurea group but is a representative
of a class of substances which is new in diabetes therapy,
namely sulfapyrimidine derivatives. Redul contains the
sodium salt of 2-benzenesulfonamido-5-(methoxyethoxy)pyrimidine ( I ) - generic name: glycodiazine - which is
readily soluble in water and methanol; its molecular weight
Angew. C h e m . internot. Edit.
Vol. 4 11965)
/ No. 2
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optically, activ, methylenetribenzocycloheptatriene, derivatives
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