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Патент USA US2403576

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Patented July 9, 1946
UNITED
2,403,576
STATES . PATENT 1 OFFICE
2,403,576
METHOD or RECOVERING SUBSTITUTED
ACETAMIDES
I
.
Chester'Wayne Bradley, deceased, late of Old
Greenwich, Conn., by Margaret 11. Bradley,
administratrix, Greenwich, Conn, assignor to
American Cyanamid Company, New York, N. Y.,
a corporation of Maine
No Drawing. Application April 18, 1945,
Serial No. 589,087
4 Claims.
1
The present invention relates to the production
of ?uoroacetamide, and more particularly to a
method of removing ?uoroacetamide from a mix
ture of chloroacetamide, potassium ?uoride
and/or potassium chloride.
Heretofore it hasbeen proposed to produce
?uoroacetamide by heating together chloroacet
(Cl. 260—561)
2
then separated by fractional distillation, and the
ethyl ?uoroacetate converted to ?uoroacetamide
by known methods.
The following examples in which the parts are
by weight further illustrate the invention:
Example 1
A mixture consisting of 93.5 parts of chloro
acetamide, 116 parts of potassium ?uoride and
amide and potassium ?uoride at a temperature‘
within the range of from about 100°-180° C. The
chloroacetamide and potassium ?uoride are thor 10 435 parts of xylene was stirred and heated to a
oughly mixed together, preferably in the propor
temperature of about 135° 0., in a vessel equipped
tion of about 2 mols of the former to 3 mols of
with a dropping funnel, stirrer and a take-off
?tted with a condenser. The distillate containing
the latter, and the mixture heated under reduced
pressure in a reaction vessel so arranged that the
xylene was collected in a receiver immersed in an
?uoroacetamide, as it is formed, is removed from 15 ice-water bath so as to precipitate the ?uoroacet
amide. Xylene was gradually added to the mix
the reaction zone and condensed. The ?uoro
ture in the vessel by means of the dropping fun
acetamide is thus obtained while maintaining the
reaction mixture preferably at 130°—145° C. under
nel so as to maintain approximately the original
a pressure of from 15-25 mm. Sub-atmospheric
volume. The run was continued until 1218 parts
pressures are necessary according to this prior 20 of xylene had been distilled. Upon ?ltering the
proposal as otherwise a ?uoroacetamide distilling
cold xylene distillate, there were obtained 42 parts
temperature causes at least partial decomposition
of a white crystalline product which melted at
106°-10'7° C. As the melting point of pure ?uoro
of the desired product. If therefore, a distilla
tion or removal temperature could be used lower .
acetamide is 108° 0., the product was contami
than that at which ?uoroacetamide decomposes, 26' nated with only a small quantity of the chloro
a simpler and more efficient process would result.
compound.
Example 2
The principal object of this invention is to pro
vide an improved method of removing ?uoroacet
The procedure of Example 1 was repeated using
amide from a mixture of chloroacetamide, potas
a larger vessel and a charge consisting of 500
30
sium ?uoride and/ or potassium chloride, and thus
parts of chloroacetamide, 500 parts of potassium
avoid the use of vacuum equipment as employed
?uoride and 1740 parts of xylene. Additional
in the above known process.
xylene was added during the run and approxi
It has now been discovered that an inert liquid,
mately 3480 parts were distilled. 183 parts of a
boiling at a temperature within the range of
white crystalline product melting at 102° C. were
130°-145° C. at atmospheric pressure, may be in
obtained from the xylene distillate. The product
corporated in the mixture of chloroacetamide,
by analysis was found to contain 84% ?uoroacet
potassium ?uoride and/or potassium chloride and
amide.
thus function as a carrier in removing the ?uoro
While the invention has been described with
acetamide from the reaction zone.
particular reference to speci?c embodiments, it is
Xylene has been found to be a suitable carrier 40 to be understood that it is not to be limited there
in the process, For instance, when a mixture of
to but it is to be construed broadly and restricted
chloroacetamide, potassium ?uoride and xylene
solely by the scope of the appended claims.
is heated to a temperature of about 135° C., the
It is claimed:
xylene gradually distills from the mixture and
1. In a method of producing ?uoroacetamide
carries with it the desired ?uoroacetamide, the
from a mixture of chloroacetamide, potassium
latter being soluble in hot xylene and substan
?uoride and xylene heated to a reaction temper;
tially insoluble in the cold liquid at room temper
ature, the steps which include subjecting the re
ature or below.
action mass to a distillation temperature, and
During the distillation, there is the possibility
separating a mixture of chloroacetamide and
of having some of the chloroacetamide carry over 50 ?uoroacetamide from the xylene in the distillate.
with the ?uoroacetamide. Where a very pure
2. In a method of producing ?uoroacetamide
?uoroacetamide is desired, the latter may be re
from a mixture of chloroacetamide, potassium
covered by esterifying the crude product and thus
?uoride and xylene heated to a reaction tempera
form, for instance, a mixture of ethyl ?uoro
ture, the steps which include subjecting the re
acetate and ethyl chloroacetate. The esters are 5 action mass to a distillation temperature within
2,403,676
3
the range of 130°-145° C., and separating a mix
ture of chloroacetamide and ?uoroacetamide '
from the xylene in the distillate.
3. In a method of producing‘ fluoroaoetamide
from a mixture of chloroaoetamide, potassium
?uoride and xylene heated to a reaction temper
ature, the steps which include subjecting the
reaction mass to a distillation ‘temperature of
4
from a mixture of chloroacetamide, potassium
?uoride and xylene heated to a reaction temper
ature, the steps which include subjecting the
reaction mass to a distillation temperature, and
separating a mixture _ of chloroacetamide and
?uoroacetamide from the xylene in the distillate
by cooling the distillate to a fluoroacetamide pre
cipitating temperature.
about 135° 0., and separating a mixture of
MARGARET H. BRADLEY,
chloroacetamide and ?uoroacetamide from the 10 ‘ Administratrix of the Estate of Chester Wayne
xylene in the distillate.
'
'
- ‘
_ Bradley, Deceased.
4. In a method of producing ?uoroacetamide
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