close

Вход

Забыли?

вход по аккаунту

?

Fluorothiocarbonyl Isothiocyanate.

код для вставкиСкачать
COMMUNICATIONS
Gattermann Aldehyde Syntheses with s-Triazine in
Place of Hydrogen Cyanide I*]
The Gattermann aldehyde synthesis with (2) can also be
effected with condensed aromafic ring systems. Thus 3hydroxyphenanthrene-4-carbaldehyde(8) can be prepared
in 6 4 % yield by the action of (2) o n 3-phenanthrol in
benzene at 45 OC in the presence of AIC13.
By A . Kreutzberger [*I
In syntheses of polymethine dyes by treatment of s-triazine
(2) with quaternary five- or six-membered heterocycles [21,
aldimines have been postulated - but not isolated - as
intermediates [31.
We have succeeded in preparing the hydrochlorides of such
aldimines in the furan and pyrrole series by treating (2) with
2-methylfuran ( l a ) or the pyrrole derivatives (16) to (Id).
The reaction takes place at room temperature when anhydrous hydrogen chloride is passed into a solution of (2)
and one of the compounds ( l a ) to (Id). In order to prepare
the aldehyde ( 4 ) , the aldimine hydrochloride (3) is hydrolysed by water or dilute acids or bases without prior isolation.
q$
H'
Received: July 4th. 1967
[Z 559 IE]
German version: Angew. Chem. 79, 978 (1967)
Publication delayed at author's request
.-
[*I Doz. Dr. A. Kreutzberger
Institut fur pharmazeutische Chemie der Universitat
Hittorfstrasse 58-62
44 Miinster (Germany)
[l] This work was supported by the Verband der Chemischen
Industrie.
[2] A . Kreurzberger in: Berichte - XXIII. Internationaler Kongress der Pharmazeutischen Wissenschaften. Govi-Verlag GmbH,
Frankfurt/Main 1963, p. 311; Angew. Chern. 77, 1086 (1965);
Angew. Chem. internat. Edit. 4, 1090 (1965); Arch. Pharrnaz.
299, 984 (1966).
[3] A . Kreutzberger, Arch. Pharmaz. 299, 897 (1966).
R'
X
or m.p. ("C)
I
I
Reactive aromatic compounds including those of the carbocyclic series, such as phloroglucinol (Sa) and orcinol (Sb),
undergo this aldehyde synthesis without a Friedel-Crafts
catalyst. Even in cases where the Gattermann synthesis b i t h
hydrogen cyanide depends o n the presence of aluminum
k),the synthesis can be
chloride, as with pyrogallol (
effected with s-triazine without a catalyst. However, phenol
ethers and aromatic compounds lacking an activating substituent undergo the aldehyde synthesis with (2) only at
elevated temperature and then only in the presence of a
Friedel-Crafts catalyst.
R3
(a)
(b)
(c)
(d)
(e)
(f)
940
OH
OH
OH
H
H
OH
OH
OH
OH
n
H
H
om3
H
H
H
OC~HS
H
OH
CH3
H
H
H
H
Solvent
Fluorothiocarbonyl Isothiocyanate
By A . Haas and W. Klug[*l
The presumed bifunctional behavior of C1-CO-SCI (1) in
its reaction with silver pseudohalides [ I ] led us to study whether the C-CI bond in chlorofluorothiocarbonyl S-CC1F (2)
is susceptible to attack by silver salts. In this compound, as in
compound ( I ) , the carbon is sp2 hybridized.
There was no reaction when compound (2) was treated with
silver cyanate at room temperature; similarly, reaction of ( 1 )
with AgCNO involves replacement of only the C1 atom
attached to sulfur by a NCO group.
However, when (2) is treated with AgSCN (molar ratio
1:1.15) in a bomb tube at -25OC, fluorothiocarbonyl isothiocyanate S=CF-NCS ( 3 ) is obtained in 50 to 60% yield
(calculated OR the amount of (2) used). This product is an
orange liquid of b.p. 35'C/40mm and has an extremely
pungent odor!'At room temperature it slowly becomes red,
and at higher temperatures it decomposes rapidly to dark
solids. It was characterized by elemental analysis and by IR,
IgN-NMR, and mass spectra.
1
R
Temp.
"C)
25
25
25
40
40
100
I
i
I
292-295 (decomp.)
179- 180
158-159
137-138/18
158- 15914
86-87/40
77
86
61
67
78
31
Angew. Chem. infernat. Edit.J Vol. 6 (1967)
No. I1
The I R spectrum measured in the NaCl and KBr regions
shows strong absorptions at 1208, 1298, and 1972 cm-1 and
bands of medium strength at 511, 843, 930, 956, 2043, 2395,
2500, 2633, and 2930 cm-1.
The 19F-NMR spectrum at 30 "C contains one very broad
signal, which becomes narrower with decrease in the temperature. At -60°C the chemical shift amounts to -55.1 ppm
referred to CC13F as internal standard.
The mass spectrum of (3) contains the typical fragments
SC-NCS ( m / e = 102), CNCS (70), SCF (63), CS (44), and
F C (31), as well as the molecule ion at m / e = 121.
An equimolar mixture of (3) and chlorine reacts at -70 "C
in a bomb tube in an extremely short time, the color becoming
paler and the chlorine being consumed quantitatively. Elemental analysis and the IR, 19F-NMR, and mass spectra of
the yellow liquid product showed that FCI(SCN)C-SCI ( 4 )
is formed quantitatively in this reaction; this compound boils
at 53 "CjlO mm and has the typical odor of sulfenyl chlorides.
The IR spectrum contains a strong absorption band at 1958
cm-1 and bands of medium strength at 530, 575, 811, 1040,
and 1165cm-1. The 19F-NMR spectrum of ( 4 ) at 3OoC
contains a single signal with chemical shift +44.7 ppm referred to CC13F as internal standard. The mass spectrum shows,
inter aliu, fragments FCl(S)C-NCS ( m / e = 156), FClC-NCS
(124), F(S)C-NCS (121), and SCClF (98).
Received: May 26th and June 5th, 1967
[Z 540b IE]
German version: Angew. Chem. 79,978 (1967)
Publication delayed at author's request
*! Dozent Dr. A. Haas and Dip1.-Chem. W. Klug
Anorganisch-Chemisches Institut der Universitat
Hospitalstr. 8-9
34 Gottingen (Germany)
[l] A. Huas and H. Reinke, Angew. Chem. 79, 687 (1967);
Angew. Chem. internat. Edit. 6,705 (1967).
Half-wave Reduction Potentials of
2,5-Bis(trimethylsilyl)- and
2,5-Di-t-butyl-l,Cbenzoquinone[**I
By H. Bock and H. A f t [*I
The interpretation of d-orbital effects
is made difficult in
the case of phosphorus-nitrogen compounds according to the
oxidation state and coordination number of phosphorus by
the presence of free electron pairs, positive charges, or partial
double bonds. However, the d-x and d-x* interactions and
their differences can be investigated by comparing siliconsubstituted x-electron systems with the corresponding alkyl
derivatives using suitable methods of measurement [21. Thus
the half-wave reduction potentials Ell, are related to the
eigenvalues of the lowest unoccupied levels of n-electron
systems into which the electron is inserted on reduction [31.
The prerequisite of a reversible redox equilibrium is fulfilled
for alkylated p-benzoquinones 141.
The 2,5-bis(trimethylsilyl)-l,4-benzoquinone (5) needed for
comparison with the 2,Sdi-t-butyl derivative was obtained
as follows: ( I ) is converted with trimethylchlorosilane/
qBr
- &rBr RQSiO
Br
OH
(1)
R,SiO
R3si@siR3
OSiR3
R
H
C(CH,),
Si(CH3),
+0.04
-0.15
+0.04
-0.47
-0.71
-0.51
The results show that the silicon-substituted quinone and
semiquinone have higher oxidation potentials than the alkyl
derivatives, i.e. they are stronger electron-acceptors. This is
inexplicable if one assumes exclusively an inductive effect
(+ISiR3 > + I c R ~ ) [ ~ Jand indicates an additional d-x*
interaction between the vacant 3d levels of the silicon and
the lowest unoccupied or singly occupied molecular orbitals
of the p-benzoquinone x-system.
This type of model, already postulated several times171, for
the Si-C,,z
bond, which requires Sid c C, back-donation
of electrons alongside the 8% + Cs- inductively polarized
5 skeleton, is in accord with the results of further polarographic measurements on silyl- and alkyl-butadienes, -styrenes, -naphthalenes, and -phenyl ketones 121.
Received: July 24th. 1967
[Z 591a IE]
German version: Angew. Chem. 79, 932 (1967)
[*I Priv.-Doz. Dr. H. Bock and Dip1.-Chem. H. Alt
Institut fur Anorganische Chemie der Universitat
Meiserstr. 1
8 Miinchen 2 (Germany)
[**I Part I of d-Orbital Effects in Silicon-substituted x-Electron
Systems.
[I] Cf. H. Bock, Chimia 21, 35 (1967).
[2] H. Bock, H. Alt, [J. Krjnitz, and H. Xidl, unpublished.
131 Cf. A. Sfreifwieserj r . : Molecular Orbital Theory for Organic
Chemists. Wiiey, New York 1961, p. 173f.
[4] M. E. Peover, J. chem. SOC.(London) 1962, 4540.
[ 5 ] P. H. Given and M. E. Peover, J. chem. SOC.(London) 1959,
1602.
[6] H. Bock and H . AIt, Angew. Chem., in press.
I71 Cf.,e.g., M . D . Curtis and A. C. Alfred, 3. Amer. chem. SOC.
87, 2554 (1965).
OSiRS
131
(2)
pyridine in boiling toluene into the ether (2) (m.p. 58-59 " C )
which reacts with sodiumjtrimethylchlorosilane in boiling
toluene to form (3) (m.p. 121 "C). Cleavage of the O-SiR3
bonds with 4 M sodium methoxide in methanol at 20 "C leads
after neutralization with diluted acetic acid to ( 4 ) (m.p. 183
to 186'C), which can be oxidized with silverli) oxide in
benzene at 20 "C to (5).
The 2,5-bis(trimethylsilyl)-l,4-benzoquinone (n + x * : vm =
19999 cm-1; E~ = 25 1 mole-1 cm-1) is orange in contrast
t o the yellow 2,Sdi-t-butyl compound (n +x* : vn, = 21 900
cm-1;
= 36 1 mole-1 cm-1); it melts a 188 OC and gives
two N M R singlets at T = 3.24 and 9.77 in the required ratio
2: 18. The half-wave reduction potentials for the two steps (I)
and (11) in acetonitrile were measured with tetra-n-butylammonium iodide as conducting electrolyte against the
constant 151 mercury anode.
U V and ESR Studies of p-Bis(trimethyIsily1)- and
p-Dialkylbenzenes[**I
By H. A h , H. Bock, F. Gerson, and J. Heinzer[*]
A notable feature of the U V spectrum of p-bis(trimethy1sily1)benzene ( I n ) , when compared with the UV spectrum
of p-di-t-butylbenzene, is that the lLa band (lBlu -+ lAlg)
Angew. Chem. internat. Edit.
Vol. 6 (1967)
1 No. I 1
94 1
Документ
Категория
Без категории
Просмотров
0
Размер файла
213 Кб
Теги
fluorothiocarbonyl, isothiocyanate
1/--страниц
Пожаловаться на содержимое документа