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New Synthesis of N-(Dichloromethylene)carboxamides.

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Preparation of Chlorobis(trifluoromethy1thio)methanesulfenyl Chloride, (F3CS)2CCl -SCI,
and Chlorofluoro(trifluoromethy1thio)methanesulfenyl Chloride, F3CS -CFC1 -SCI
141 vs = very strong, br = broad, s = strong, sh = shoulder.
m = medium.
[ 5 ] Measured for a 5 0 % solution in C13CF which acted as
internal standard.
By Dr. A. Haas and W. Klug
New Synthesis of N-(Dichloromethy1ene)carboxamides
Anorganisch-Chemisches Institut,
Universitat Gottingen (Germany)
By Dr. D. Pawellek
Carbonyl fluoride, COF2, reacts with alkali fluorides MF
(M = K , Rb, or Cs) in acetonitrile at room temperature,
giving trifluoromethoxides, MOCF3 [I].
After the analogous reaction of thiocarbonyl fluoride, CSF2,
with CsF we could isolate no CsSCF3. Instead, a deep red
solution is rapidly obtained, even at -44 “C, with quantitative
consumption of the CSF2. On fractional distillation this
liquid yields CH3CN, a yellow liquid ( I ) , b.p. 43OC, and
as main product a dark red liquid (2), b.p. 111 ‘C. The IR
spectra, colors, and boiling points show that the yellow
liquid ( I ) is the “pseudodimer” F3CS-CF-S of CSF2, and
that the red liquid (2) is bis(trifluoromethy1)trithiocarbonate,
(F3CS)zCS [21. All the CsF added is recovered.
In absence of solvent, CSF2 and CsF (molar ratio 1:60) in
a sealed tube at -78 “C quantitatively give a white powder
which changes gradually at room temperature to a yellow
to red, transparent mass. When the volatile constituents are
removed at room temperature in a high vacuum, a white
solid remains which is soluble in chloroform. From the
chloroform solution methanol precipitates a viscous, rubberlike product. Quantitative analysis and molecular-weight
determination show this to be a polymer of CSF2[31.
Reaction of CSF2 and CsF without solvent is extremely fast
at 0°C: the ester (2) was the sole product found.
CSF2 reacts analogously with K F or NH4F, but the ratio
MF:CSF2 may not be varied indefinitely, as it can for CsF.
Also, the reactions are appreciably slower and require
higher temperatures.
Compounds ( I ) and (2) react with chlorine even at -60°,
giving the sulfenyl chlorides (3) and ( 4 ) rapidly and quantitatively :
These materials, yellow liquids with pungent odor, were
identified and characterized by elemental analyses, IR
spectra, and NMR measurements.
(3) : B.p. 113 “C. IR: vmax = 1165 cm-1 (vs, br) 141, 1102 (vs,
br), 1039 (vs), 1012 (sh), 792 (vs), 528 (s), 467 (m), 410 (m).
The 19F-NMR spectrum consists of a doublet (CF3) and a
quadruplet (CF) with chemical shifts of ~ C F ,= 38.1 ppm,
~ C =
F 57.6 pprnrsl, and coupling constants JF-F = 22.0 Hz.
The starting material ( I ) also gives a doublet and a quadruplet, ~ C F ,= 42.97 ppm, ~ C F= -89.6 ppm, JF-F =
18.0 Hz.
4 : B.p. 4OoC/0.1 mm. IR: vmax = 1745 cm-1 (m), 1165 (vs,
br), 1097 (vs, br), 1011 (sh), 801 (s), 754 (vs), 712 (m), 513
(m), 466 (m), 446 (m). IgF-NMR: ~ C F ,= 39.1 ppm. Start~ ppm.
ing material (2) : ~ C =F42.0
Received: July 25th, 1966
[ Z 294 IEI
German version: Angew. Chem. 78, 906 (1966)
[I] M . E. Redwood and C . J . Willis, Canad. J. Chern. 43, 1893
[2] N . R . Hasreidine and J. M . Kidd, J. chem. SOC.(London)
1955, 3871.
[3] H . C. Walter, US-Pat. 3032537 (May lst, 1962), Du Pont.
Angew. Chem. internat. Edit. 1 Vol. 5 (1966)1 No. 9
Wissenschaftliches Laboratorium der A-Fabrik,
Farbenfabriken Bayer AG., Leverkusen (Germany)
Reaction of sulfur dichloride with cyanogen chloride gives
chlorosulfenyl isocyanide dichloride 111. We have treated
carbonyl chlorides with cyanogen chloride, obtaining N-(dichloromethy1ene)carboxamides ( I ) . The new process has the
advantages of easily accessible starting materials compared
with the chlorination of isonitriles 121, isothiocyanates 131, and
N-acyldithiocarbamic esters [41.
The table shows some examples of compounds thus obtained.
CICO(CHz)? 101-103
For the synthesis of N-(dichloromethylene)chloroacetamide,
152 ml of chloroacetyl chloride was placed in an enamelled
shaking autoclave (capacity 0.7 l), and 300 ml of cyanogen
chloride (molar proportions 1:3) were pressed in. After
2 hours’ heating at 50°C/5 atm the pressure was released
and unchanged cyanogen chloride was condensed in cooled
receivers. The product was isolated in 64 % yield by fractional distillation of the residual reaction mixture. Synthesis
of the other products (cf. table) was achieved analogously;
further, N-(dichloromethylene)methoxymethylamine, b.p.
40 OC/25 mm, was prepared in 10 % yield from chloromethyl
methyl ether and cyanogen chloride.
These compounds decompose when stored, even in the dark,
and faster when heated, into acid chloride and (trimerizing)
cyanogen chloride. The temporary appearance of isocyanide
dichlorides could be demonstrated by IR spectroscopy in
reacting mixtures of cyanogen chloride and acetyl chloride.
Extension of the reaction of chloroacetyl chloride to other
nitriles was successful only with 4-cyanomorpholine, then
yielding a-chloro-N- [chloro(morpholino)methylene]acetamide, b.p. 110-115°C/15 mm, -CO-N/
band at 1680
cm-1, -N=C’
band at 1590 cm-1 under the above conReceived: July .15th, 1966
[ Z 302 IE]
German version: Angew. Chem. 78. 908 (1966)
[I] R . G. R . Bacon, R. S . Irwin, J. M . Pollock, and A . D. E.
Pullin, J. chem. SOC.(London) 1958, 764; erroneously considered
by these authors to be CIS-CCI=NCI.
[2j J. U.Nef, Liebigs Ann. Chem. 270, 267 (1892).
[3]B. 4ndt.r~andE.Kiihle,Germanpubl. Pat.Appl. 1178422(1964).
141 J . B. Douglas and T. B. Johnson, J. Amer. chem. SOC.60,
1486 (1938).
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synthesis, carboxamides, dichloromethylene, new
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