Molecular sieve abstract
There is provided a process for preparing amides which comprises
reacting an amine, or an amide, and an acid halide, or anhydride,
in suitable molecular proportions, in an inert organic diluent,
in the presence of an effective amount of a molecular sieve, until
the reaction is completed, separating the molecular sieve, and recovering
the amide from the organic mother liquor.
Molecular sieve claims
We claim:
1. A process for preparing amides which comprises reacting an amine,
or amide, and an acid halide, or anhydride, in suitable molecular
proportions, in an inert organic solvent, in the presence of an
effective amount of a molecular sieve, until the reaction is completed,
separating the molecular sieve and without another acid-binding
agent, and recovering the amide from the organic mother liquor.
2. The process of claim 1 wherein the amount of molecular sieve
used is about 1-2 parts by weight per part by weight of amine, or
amide.
3. The process of claim 2 wherein the amount of molecular sieve
used is about 1.2-1.7 parts by weight per part by weight of amine,
or amide.
4. The process of claim 1 wherein the molecular sieve is powdered
potassium aluminosilicate of the formula (I),
with a pore mesh diameter of about 3-5 angstroms, wherein Y is
an indefinite integer.
5. The process of claim 1 wherein the amide is a compound represented
by formula (II) ##STR2## wherein R represents hydrogen; alkyl of
1 to 6 carbon atoms; cycloalkyl of 4 to 8 carbon atoms; substituted
alkyl or cycloalkyl wherein the substituents are selected from halo,
carboxy, alkoxy, or alkoxycarbonyl, wherein the alkoxy is of 1 to
6 carbon atoms; alkanoyl of 2 to 18 carbon atoms; aroyl of 7 to
11 carbon atoms; aralkyl of 7 to 11 carbon atoms; carbocyclic aryl
of 6 to 10 carbon atoms; heterocyclic aryl of 3 to 9 carbon atoms;
substituted carbocyclic and heterocyclic aryl of 6 to 10 and 3 to
9 carbon atoms, respectively, wherein the substituents, one or more,
are selected from halo, nitro, cyano, trifluoromethyl, alkyl and
alkoxy of 1 to 6 carbon atoms, hydroxy, phenoxy, benzyloxy, phenyl,
alkanoylamino of 2 to 6 carbon atoms, benzoylamino, alkylsulfonyl
of 1 to 6 carbon atoms, carboxy, alkoxycarbonyl and alkoxysulfonyl
wherein the alkoxy group has 1 to 6 carbon atoms, --SO.sub.3.sup..crclbar.
M.sup..sym. wherein M.sup..sym. is a cation selected from sodium,
potassium, lithium, ammonium, monoalkylammonium, dialkylammonium,
trialkylammonium, or tetraalkylammonium wherein the alkyl radicals
have 1 to 6 carbon atoms, and may be the same or different, aminocarbonyl,
and aminosulfonyl which are unsubstituted or substituted at the
nitrogen by 1 or 2 radicals selected from alkyl of 1 to 6 carbon
atoms, phenyl, or substituted phenyl wherein the substituents are
as defined above for carbocyclic and heterocyclic aryl, and the
acid halide is oxalyl chloride.
6. The process of claim 5 wherein the amount of molecular sieve
used is about 1-2 parts by weight per part by weight of compound
of formula (II).
7. The process of claim 6 wherein the molecular sieve is powdered
potassium aluminosilicate of formula (I) with a pore mesh diameter
of about 3-5 angstroms.
8. The process according to claim 1 wherein the molecular sieve
used has been reactivated by heating at an elevated temperature.
9. The process according to claim 5 wherein the molecular sieve
used has been reactivated by heating at an elevated temperature.
Molecular sieve description
The present invention relates to a process for preparing amides,
more particularly N,N'-bis(trifluoromethylsulfonyl)oxamide compounds,
which are useful for generating chemiluminescence by reaction with
a hydroperoxide.
The preparation of amides by the reaction of amines or amides with
acid halides, or anhydrides, in the presence of an acid-binding
agent, is well-known in the art. Methods for the preparation of
trifluoromethanesulfonanilides and N-substituted trifluoromethanesulfonamides,
in particular, are disclosed by Harrington et al., U.S. Pat. Nos.
3558698; 3629332; 3799968; 3865844; 3897449; 3920444;
and Moore et al., U.S. Pat. No. 3609187. While the processes disclosed
hitherto can be used to prepare the desired amides and sulfonamides,
there is a need for an improved process that will facilitate the
preparation, by eliminating the need for the removal of reaction
by-products by subsequent washing with dilute acid and extraction
with dilute aqueous caustic soda, before recovering the product.
SUMMARY OF THE INVENTION
In accordance with the present invention, there is provided a process
for preparing amides which comprises reacting an amine, or an amide,
and an acid halide, or anhydride, in suitable molecular proportions,
in an inert organic diluent, in the presence of an effective amount
of a molecular sieve, until the reaction is completed, separating
the molecular sieve, and recovering the amide from the organic mother
liquor.
Preferably, the molecular sieve is powdered potassium aluminosilicate
of the formula (I)
wherein Y represents an indefinite number, having a pore mesh diameter
of about 3-5 angstroms, and it is used in about 1-2 parts by weight
per part by weight of amine, or amide.
Preferably, the amide is a compound represented by formula (II)
##STR1## wherein R represents hydrogen; alkyl of 1 to 6 carbon atoms;
cycloalkyl of 4 to 8 carbon atoms; substituted alkyl or cycloalkyl
wherein the substituents are selected from halo, carboxy, alkoxy,
or alkoxycarbonyl, wherein the alkoxy is of 1 to 6 carbon atoms;
alkanoyl of 2 to 18 carbon atoms; aroyl of 7 to 11 carbon atoms;
aralkyl of 7 to 11 carbon atoms; carbocyclic aryl of 6 to 10 carbon
atoms; heterocyclic aryl of 3 to 9 carbon atoms; substituted carbocyclic
and heterocyclic aryl of 6 to 10 and 3 to 9 carbon atoms, respectively,
wherein the substituents, one or more, are selected from halo, nitro,
cyano, trifluoromethyl, alkyl and alkoxy of 1 to 6 carbon atoms,
hydroxy, phenoxy, benzyloxy, phenyl, alkanoylamino of 2 to 6 carbon
atoms, benzoylamino, alkylsulfonyl of 1 to 6 carbon atoms, carboxy,
alkoxycarbonyl and alkoxysulfonyl wherein the alkoxy group has 1
to 6 carbon atoms, --SO.sub.3.sup..crclbar. M.sup..sym. wherein
M.sup..sym. is a cation selected from sodium, potassium, lithium,
ammonium, monoalkylammonium, dialkylammonium, trialkylammonium,
or tetraalkylammonium wherein the alkyl radicals have 1 to 6 carbon
atoms, and may be the same or different, aminocarbonyl, and aminosulfonyl
which are unsubstituted or substituted at the nitrogen by 1 or 2
radicals selected from alkyl of 1 to 6 carbon atoms, phenyl, or
substituted phenyl wherein the substituents are as defined and the
acid halide is oxalyl chloride.
The process of the present invention offers the following advantages
over the prior art:
1. Bases, such as triethylamine, which may cause undesirable side
reactions, are not required.
2. The reactions are carried out in a heterogeneous phase, thus
simplifying the subsequent workup.
3. Acids produced during the reaction are rapidly adsorbed by the
powdered molecular sieves, thus eliminating undesirable side reactions
and by-products.
4. The molecular sieves also adsorb water, thus maximizing the
anhydrous conditions for the reaction.
5. The molecular sieves can be reactivated for subsequent use.
DESCRIPTION OF PREFERRED EMBODIMENTS
The process of the present invention is readily carried out by
reacting a suitable amine, or amide, with an acid halide, or anhydride,
in suitable molecular proportions in an inert diluent in the presence
of a suitable molecular sieve. Generally, the acid halide, or anhydride,
is added dropwise to a suspension of amine, or amide, and molecular
sieve in dichloromethane at room temperature, preferably under a
nitrogen atmosphere. After the addition is completed, the reaction
mixture is heated to a temperature high enough to dissolve any product
which may have precipitated. Generally, the reaction is carried
out at a temperature from about 0.degree.-100.degree. C., preferably
about 25.degree.-60.degree. C., for a period of about 2-48 hours,
preferably about 4-10 hours. The molecular sieves are then removed
by filtration, or centrifugation, and the product is recovered from
the mother liquor. The amount of molecular sieve used is usually
about 1-2 preferably about 1.2-1.7 parts by weight per part by
weight of amine or amide used. Purification of the crude product
is effected by recrystallization or distillation.
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