вход по аккаунту


Friedel-Crafts Reactions of Octachlorocyclotetra-(phosphazene).

код для вставкиСкачать
The pH-stat test can be used between p H = 5.2 and 7.5. The
enzyme activities found a t various p H values exhibit good
agreement with those reported by Singer and Pensky [21.
The pH-stat test can also be used t o measure the decarboxylation rate of substrate analogs such as aliphatic a-keto acids
and substituted phenylglyoxylic acids, which cannot be measured by the optical test. Since no auxiliary enzyme system is
required, the determination can also be carried out in the
presence of product.
[ * ] V. B. Desai, Prof. R. A. Shaw, and Dr. B. C. Smith
Department of Chemistry,
Birkbeck College (University of London),
Malet Street
London, W.C.1. (England)
[l] For a summary see R . A . Shaw, B. W. Fitzsimmons, and B. C.
Smith, Chem. Reviews 62, 247 (1962).
[ 2 ] M. Biddlestone and R . A . Shaw, Chem. Commun. (London)
1965, 205; R. Keat, M. C. Miller, and R . A . Shaw, J. chem. SOC.
(London) A 1967, 1404.
Received: July 29, 1968
[Z 864 IE]
German version: Angew. Chem. 80, 907 (1968)
[*I Prof. Dr. A. Schellenberger, Dr. G. Hubner, and
H. Lehmann
Institut fur Biochemie, Chemische Abteilung der Universitat
DDR 401 Halle/Saale (Germany)
[l] E . Holzer, H.-D. Soling, H. W. Goedde, and H. Holzer in H.
U. Bergmeyer: Methoden der enzymatischen Analyse. Verlag
Chemie, Weinheim/Bergstr. 1962, p. 602.
[2] T . P. Singer and J . Pensky, J. biol. Chemistry 196,375 (1952).
Dimethyl Pentacyclo[]nonane1,7-dicarboxylate I
By H. Prinzbach, W. Eberbach. and G . Philippossian [*I
Compounds with the tetracyclo[]octane
skeleton ( 3 ) , the next higher homolog in the series prismane ( I ) ,
quadricyclane (21, have often been postulated as intermediates but their existencelhas not yet been directlyproved [*].
Friedel-Crafts Reactions of Octachlorocyclotetra(phosphazene)
By V. B. Desai, R . A . Shaw, and B. C. Smith[*]
Friedel-Crafts reactions of octachlorocyclotetraCphosphazene) have been attempted, but no pure products have been
isolated [I]. The preparation of two crystalline compounds
from the reaction with benzene is reported here.
A mixture of octachlorocyclotetra@hosphazene) (14.1 g),
anhydrous aluminum chloride (30.9 g), and triethylamine
(9.2g) in benzene (620ml) was boiled under reflux (48 h).
The product was divided into two portions.
We have now isolated the system (8a) that is very closely
related t o the tetracycle ( 3 ) .
Compound (8a) is formed in at least 80 % yield [3J o n direct
irradiation (Hanau Q-81 lamp, Pyrex filter, 2 h) of a n ethereal
solution (100 mg/300 ml) of “monohomobarrelene” (5a)
(ether) = 257 nm (E = 2060; €280 nm = 800)] cooled
t o -20 O C .
1. Hydrolysis by cold dilute hydrochloric acid, extraction
Apparently this (277 + 2 x) cycloaddition ( 5 ) + (8) is not
with benzene, and filtration through short alumina and silica
columns gave 2,2,4,4-tetrachloro-6-phenyl-6-(2,2.2-triphenyl- detectably (NMR analysis) accompanied by (2x + 2s) addition ( 5 ) + ( 4 ) in spite of the stereoelectronically favorable 141
phosphazeny1)cyclotriCphosphazene) ( I ) (yield 0.6 %, m.p.
exo-arrangement of the three-membered ring 151 to the suband mixed m.p. 181 ‘C)[*l. The product was isolated by restituted (excited) C=C double bond. Moreover, there was no
crystallization from light petroleum (b.p. 40-60 “C) ’methylindication that (6a) was formed, although this product
ene chloride (1: 1).
would be the one most expected on triplet sensitization[61.
This is the first reported example of a ring contraction resultThe photoproduct (8a) is very unstable thermally. When the
ing from Friedel-Crafts reactions i n the phosphazene series
photosolution is warmed, (8a) rearranges quantitatively
of compounds.
( N M R accuracy) to ( h i , the half-life (CHC13) at 21.5”C
2. An excess of dimethylamine was added at O O C , and the
mixture was boiled under reflux (1 h). Filtration through a
short silica column gave dichlorodimethylaminopentaphenylH3b
cyclotetra@hosphazene) (2), which was isolated by recrystallization from light petroleum (b.p. 40-60 ‘C)/methylene
chloride (1 : 3) (yield 0.6%, m.p. 171 “C).
The dimethylamino IH-NMR spectrum of this product
(3Jp-H 11.6 Hz) confirms the presence of a P(C6Hs)N(CH3)2
group. The mass spectrum exhibits a peak at mje 680 cor4 )] + ,
responding t o the molecular ion [ N ~ P ~ ( C ~ H ~ ) ~ C ~ Z N ( C H ~ )( ~
but no peak occurs at m/e 262 corresponding to the fragment
[P(C6H5)3]+. The broad P=N stretching band in the infrared
spectrum occurs at ca. 1240 cm-1, i.e. at a higher (ca. 80 cm-1)
wave-number range than in ( I ) , thus confirming the presence
of a cyclotetra(ph0sphazene) ring [I]. The positions of the
remaining substituents are-not yet known.
( 7)
c1 c1
+ 2 c 1
+ 4 C6H,
(a), R = CH,, X
(b), R = H,
/ \
Received: August 12, 1968
[ Z 865 IE]
German version: Angew. Chem. 80, 910 (1968)
Angew. Chem. internat. Edit. 1 VoI. 7 (1968) 1 No. I I
Без категории
Размер файла
116 Кб
octachlorocyclotetra, reaction, craft, phosphazene, frieder
Пожаловаться на содержимое документа