Note: Descriptions are shown in the official language in which they were submitted.
11~77~9
Manufacture of -haloalkylcarbam~1 halides
The present invention relates to a process for the
manufact~e of ~-haloalkylcarbamyl halides by reacting vinyl
isocyanate or N-tert.-alkyl-N-(l-alkenyl)-carbamyl halides
with a hydrogen halide at from -78C to +80C.
Angewandte Chemie, 74 (1962), 848-855 discloses the
reaction of alkylcarbamyl chlorides with elementary chlorine
to give the corresponding -cnloroalkylcarbamyl chlorides.
However, the products which result are mixtures, both in
respect of the degree of halogenation and in respect of the
position of the halogen atoms entering the molecule. The
process is unsatisfactory in respect of yield and purity of
the end product, and does not permit simple and economical
operation.
We have found that -haloalkylcarbamyl halides are
obtained in an advantageous manner if vinyl isocyanate or
N-tert.-alkyl-N-(l-alkenyl)-carbamyl halides are reacted
with a hydrogen halide at from -78C to +80C.
Further, we have found the novel a-haloal~ylcarbamyl
halides of the formula
R4-CH2-C-~-C~
where R is hydrogen or alkyl of 1 to 2~ car~Gn atoms and
X i5 halogen,
,.~
lP'~7~9
o.Z. 0050/032692/794
Further, we have found the novel -haloethylcarbamyl
halides, in particular the novel -chloroethylcarbamyl
chloride-
Where vinyl isocyanate and hydrogen chloride areused, the reaction may be represented by the following
equation:
H H ~ 0
CH2=C-N-C0 + 2 HCl ~ CH~-C-N-C-Cl
Cl
Where a N-tert.-alkyl-N-(l-alkenyl)-carbamyl halide,
eg. the chloride, is used, a quantitative fragmentation into
tert.-alkyl chloride and a-chloroethylcarbamyl chloride
takes place, in accordance with the equation below:
Rl ,,C001 R2 R~ H 0
--C-~ ~ 2HC~ Cl + X ~ C~
R2-" R~ ~ CX--CH R3 R42 Cl ~C1
Compared to the conventional process, the process
of the invention gives a-haloalkylcarbamyl halides more
simply and more economically, and in better yield and in
greater purity. Working up is substantially simpler
since the reaction mixture obtained does not contain a large
number of different components.
The reaction of a tert.-alkyl-N-(l-alkeny~)-
carbamyl halide, especialiy a chloride, with a hydrogen
halide, especially hydrogen chloride, makes it possible to
prepare the heat-stable halide, especially -chloroalkyl-
carbamyl chloride~ in a particularly pure form and under
mild reaction conditions, whilst the reaction of elementary
~'~'377~9
o. z. ooso/0~26s2/7s~
halogen with an alkylcarbamyl chloride (Angewandte Chemie,
loc. cit.) gives product mixtures in respect of the
position of the halogen atom entering the molecule, and in
respect of the degree of halogenation. The tert.-alkyl
halide also formed in the reaction is inert under the con-
ventional reaction conditions and need therefore as a rule
not be removed for carrying out the further reactions of the
a-chloroalkylcarbamyl chloride.
All these advantageous results are surprising, since
the formation of a variety of reaction products was to be
expected from the great reactivity of the starting materials.
It was also to be expected that a,~-unsaturated nitrogen
compounds would polymerize or hydrolyze very easily under
the influence of acids. For example, N-vinylpyrrolidone
is converted to a mixture of oligomers under the influence
of even small amounts of an inorganic acid (Ullmanns
Encyclopadie der technischen Chemie, volume 14, page 26~).
Bull Soc. Chim. Belg., 65 (1956), 291-296 discloses that
vinyl isocyanate is hydrolyzed by aqueous 12-normal hydro-
chloric acid in acetone to give acetaldehyde
Vinyl isocyanate may be prepared, for example, by
reacting acrylyl chloride with sodium azide (Bull.Soc.
Chim. Belg., loc. cit~ or by thermally decomposing N-tert.-
butyl-N-vinylcarbamyl chloride The hydrogen halide,
advantageously hydrogen bromide and especially hydrogen
chloride, is used in the stoichiometric amount or in excess,
preferably in an amount of from 2 to 2.2 moles per mole of
vinyl isocyanate or of N-tert.-alkyl-N-(1-alkenyl)-carbamyl
halide.
1~77~9 o. z. 0050~032692~794
Suitable tertiary alkyl radicals RlR2R3-C, where R , R
and R3 may be identical or different, are those of 4 to 20
carbon atoms, and especially of 4 to 12 carbon atoms
Speclfic examples are tert.-butyl and tert.-amyl.
Accordingly, the radicals Rl to R3 in the formula given
may be alkyl of 1 to 6 carbon atoms, especially methyl and
ethyl. R is advantageously hydrogen or alkyl of 1 to 20,
especially 1 to 12, preferably 1 to 6, carbon atoms; pre~erred
meanings are hydrogen, methyl and ethyl.
The reaction is carried out at from -78C to l80C,
ad~antageously at from +40C to -78C, in the case of vinyl
isocyanate preferably at from +30C to -78C, especially at
from 0C to -40C, and in the case of N-tert -alkyl-N-(l-
alkenyl)-carbamyl halides pre~erably at from -10C to 20C,
under atmospheric or superatmospheric pressure, preferably
at from 0 7 to 2 bars, continuously or batchwise The
reaction can be carried out in the absence of a solvent,
but it is advantageous to use a solvent which is inert under
the reaction condition~ Water is not used in the case
of v~nyl isocyanate Because of the reactivity of the
resulting a-haloalkylcar~amyl halides, the reaction carried
out with the N-tert.-alkyl-N-(l-alkenyl)-carbamyl halides.is pre-
ferably carried out under anhydrous conditions, but in prin-
ciple it can also be carried out with aqueous hydrochloric
acid.
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o.Z. 0050~032592/794
Preferably, the reaction is
carried out in a solvent which serves as the reaction medium
for the further conversion of the end product, especially
of a-chloroethylcarbamyl chloride Examples of suit-
able solvents are aromatic hydrocarbons, eg toluene, ethyl-
benzene, o-, m- and p-xylene, isopropylbenzene and methyl-
naphthalene; aromatic ethers; halohydrocarbons, especially
chlorohydrocar~ons, eg. tetrachloroethylene, 1,1,2,2- or
1,1,1,2-tetrachloroethane, amyl chloride, cyclohexyl chlor-
ide, 1,2-dlchloropropane, methylene chloride, dichlorobutane,
isopropyl bromide, n-propyl bromide, butyl bromide, chloro-
form, ethyl iodide, propyl iodide, chloronaphthalene, di-
chloronaphthalene, carbon tetrachloride, 1,1,1- or 1,1,2-
trichloroethane, trichloroethylene, pentachloroethane, 1,2-
dichloroethane, l,l-dichloroéthane, n-propyl chloride, 1,2-
cis-dichloroethylene, n-butyl chloride, 2-, ~- and iso-
butyl chloride, chlorobenzene, fluorobenzene, bromobenzene,
iodober,zene, o-, p- and m-dichlorobenzene, o-, p- and m-
dibromobenzene, o-, m- and p-chlorotoluene, 1,2,4-trichloro-
benzene, 1,l-dibromodecane and 1,4-dibromobutane; ethers,
eg. ethyl propyl ether, methyl tert -butyl ether, n-butyl
ethyl ether, di-n-butyl ether, diisobutyl ether, diisoamyl
ether, diisopropyl ether, anisole, phenetole, cyclohexyl
methyl ether, diethyl ether, ethylene glycol dimethyl ether,
tetrahydrofuran, dioxane, thioanisole and ~ dichlorodi-
ethyl ether; ketones, eg. methyl ethyl ketone, acetone,
diisopropyl ketone, diethyl ketone, methyl isobutyl ketone,
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O.Z. 0050/032692t794
mesityl oxide, acetophenone, cyclohexanone, ethyl isoamyl
ketone, diisobutyl ketone, methylcyclohexanone and dimethyl-
cyclGhexanone; esters, eg. methyl acetate, n-propyl acetate,
methyl propionate, butyl acetate, ethyl formate, methyl
phthalate, methyl benzoate, ethyl acetate, phenyl acetate
and higher-boiling esters; aliphatic or cycloaliphatic
hydrocarbons, eg. pentane, heptane, pinane, nonane, gaso-
line fractions within a boiling range from 70 to 190C,
cyclohexane, methylcyclohexane, decalin, petroleum ether,
héxane, naphtha, 2,2,4-trimethylpentane, 2,2,3-trimethyl-
pentane, 2,3,3-trimethylpentane and octane; and mixtures of
these. The solvent is advantageously used in an amount
of from 200 to 10,000 per cent by weight, preferably from
300 to 2,000 per cent by weigh~, based on the vinyl isocyan-
ate starting material.
The concentration of the solutions of the N-tert.-
alkyl-N-(l-allcf3nyl)-carbamyl chlorides may be varied within
wide limits, a concentration range of from 1 to 50 per cent
by weight being used preferentially.
~ he reaction may be carried out as follows: a mix-
ture of the starting materials, advantageously with a sol-
vent, is ~ept at the reaction tempera~ure for from 0.1 to
4 hours. Advantageously, the vinyl isocyanate is
introduced into the solvent and hydrogen halide gas is
introduced at the reaction temperature, The reaction
solution is then advantageously stirred for from 0.2~ to
one hour, In the case o~ the N-tert.-alkyl-N~
alkenyl)-carbamyl halide, the compound is advantageously
introdu~ed into an inert solvent and hydrogen halide gas is
377~9
O.Z. 0050/032692/794
introduced at, for example, from -10C to 0C. After
completion of the reaction, the reaction solution is
stirred for some tlme longer, for example for i5 minutes,
and excess hydrogen halide is blown out by means of N2.
The end product is then isolated from the mixture in the
conventional manner, for example by crystallization and
filtration.
The -haloalkylcarbamyl halides, especially a-
chloroethylcarbamyl chloride, prepared by the process of the
invention, are valuable starting materials for the manu-
facture of surface-coating raw materials, textile coatings,
dyes, drugs and crop protection agents.
In the Examples, parts are by weight.
EXAMPLE 1
69 parts of vinyl isocyanate are introduced into
250 parts of carbon tetrachloride. 73 parts of hydrogen
chloride are passed into this solution in the course of one
hour at -35C. The reaction solution is then stirred
for a further 15 minutes at the same temperature. After
filtering, 13f parts (95% of theory) of a-chloroethyl-
carbamyl chloride of melting point 21C are obtained; the
NMR spectrum in CC14 (with tetramethylsilane as the stan-
dard) gives the following:
(CH3-) 1.8 ppm
~Cl-C-H3 5.8 ppm
(NH) 7.5 ppm.
EXAMPLE 2
161.5 parts of N-tert.-butyl-~-vinylcarbamyl
chloride at 0C are introduced into the reaction vessel and
- 7 -
~ 377~9 o. ~ . 0050~032692~7~4
75 parts of hydrogen chloride gas are passed in over 60 mi~-
utes. The reaction mixture is 'hen stirred for a
further 15 minutes at the same temperature, and excess HCl
is blown out with N2. Tert.-butyl chloride is stripped
off under reduced pressure and the a-chloroethylcarbamyl
chloride is recrystallized from CC14. 136 parts (95%
of theory) are obtained; melting point 20/21C,
EXAMPLE 3
175,5 parts of N-tert,-amyl-N-vinylcarbamyl chloride
are introduced into the reactor at 10C and 77 parts of HCl
are passed in whilst stirring.
After completion of the reaction, the reaction mix-
ture is stirred for a further 30 minutes at room temperature
and excess HCl is blown out with N2.
The tert,amyl chloride is stripped off under
reduced pressure,
130 parts (91,5% of theory) of a-chloroethyl-
carbamyl chloride of melting point 20C remain.-
EXAMPLE 4
50 parts of vinyl isocyanate are introduced into
150 parts of methylene chloride, 125 parts of hydrogen
bromide are passed into this solution, at -20C, in the
course of 70 minutes. The reaction solution is then
stirred for a further 40 minutes at the same temperature.
After filtering, 150 parts (90% of theory) of a-bromoethyl-
carbamyl bromide of meltingpoint 55C are obtained; the ~R
spectrum in CDC13 (using tetramethylsilane as the standard)
gi~es:
(CH3-) 2.0 ppm
(Br-C-H) 5.9 ppm
(NH) 6.8 ppm. _ 8 -
