Note: Descriptions are shown in the official language in which they were submitted.
~l~48()26
This invention relates to a process for the prepa-
ration of novel compounds, ethers of 3,4-dihydro-1-benzoxepin-
5-one oxime of the following general formula (I):
R~ (I)
N (CH2)n N~ z
wherein:
R represents a halogen atom or a lower alkoxy group;
n represents an integer which has the value 2 or 3j
Zl and Z2' which may be identical or different, represent
each a lower alkyl group or Zl and Z2 and the nitrogen
atom to which they are attached may together form a 5
to 7-membered N-heterocyclic group which may contain a
second hetero atom in particular N, 0 or S; and the
acid addition salts of the free amine function.
Formula (I) represents the two geometric isomers of
the oxime, in the cis or ~rans conf;gurat;on relative to the
benzene nucleus.
An ether of 3,4-dihydro-1-benzoxepin-5-one oxime of
the formula:
CQ ~ 0 ~
N-O-(CH2)2-N(CH3)2,HCQ
and a process for the preparation of this product have already
been described (collection Czechoslov Chem. Commun. 37 868-886
(1972)). This product differs from the products obtained
according to the invention by the position of substitution in
the benzene nucleus and by its properties. The process of
1 _ ~
~2~
preparation described in the said article is also different
from the process according to the present invention.
The process according to the present invention com-
prises intramolecular acylation of a phenoxybutyric acid which
is R-substituted in the para position to yield a 3,4-dihydro-1-
benzoxepin-5-one of the formula (II):
R ~ ~II)
which is then reacted with a compound of the formula H2N-0-A in
which A represents either the group (CH2)n-NZlZ2, in which case
an alcoholic solvent is used in an acid medium at the reflux
temperature of the solvent, or a hydrogen atom, in which case
the reaction is carried out in pyridine or ethanol under
reflux, and the intermediate compouncl thus obtained is reacted
in a basic medium with a compound of the formula X-(CH2)n-NZlZ2
in which X represents a halogen atom. In the above de-
scription, R, n, Zl and Z2 have the same meanin9 as in the
general formula (I).
The acid addition salts are prepared by the action of
a mineral or organic acid on compounds of formula (I) dissolved
in a suitable solvent.
It was found that the products prepared in this way
consisted to an extent of 95 to 100% of the geometric isomer of
the oxime in the ~s configuration in relation to the benzene
nucleus (determined with the aid of nuclear magnetic resonance,
infrared spectography and gas phase chromatography). Isolation
of this isomer is achieved in excellent yields by successive
recrystallizations of the mixture of addition salts of the free
amine function with suitably chosen acids. Isolation of its
~ L~48~
~rans homologue, on the other hand, cannot be achieved satis-
factorily. It is recommended to carry out partial isomeri-
zation after introduction of the oximino function into the
heterocyclic group by applying a method known per se, that is
to say by the action of a strong anhydrous acid, preferably a
hydrohalic acid, in an aprotic solvent. If this operation is
carried out on a compound of the formula:
~0~
R
NOH
substitution on the oxygen atom is subsequently carried out by
the general method. Isolation of the compound is achieved as
in the case of its eis homologue by recrystallization of the
acid addition salts, taking into account the fact that the
trans isomer is generally more soluble than the eis homologue.
The oxime ethers prepared in this way have in
particular a relaxing action on the smooth intestinal muscle
fibres and may be used in human therapy as intestinal regu-
lators.
The invention is illustrated by the following non-
limiting examples:
The melting points indicated were determined on a
K~fler bench. Elementary analysis of the novel compounds was
carried out and the results correspond to the generally
accepted standards (element determined: C, H, N, halogen).
That substitution took place on the oxygen atom and not the
nitrogen atom of the oxime could be confirmed by the electronic
paramagnetic resonance.
EXAMPLE 1
7-chloro-3,4-dihydro-1-benzoxepin-0-(dimethylaminoethyl)-5-one
oxime
z~
A - 7-chloro-3,4-dihydro-1-benzoxepin-5~one:
30 ml of 85% phosphoric acid (d - 1.71) are poured
into 530 ml of anhydrous toluene. 84 9 of phosphoric anhydride
are then added slowly with vigorous stirring. The mixture is
kept on a boiling water bath for 2 hours, and a tepid solution
of 24 9 of e-chlorophenoxy butyric acid(Mp = 123C) in 800 ml
of anhydrous toluene is then added~ still at the same tempera-
ture, in the course of 2 hours. Heating is continued for 5
hours and the reaction mixture is cooled.
The upper toluene phase is separated, shaken with an
equal volume of water and after decantation shaken twice with
the same volume of 5% soda. It is then neutralized by washing
with water and dried over sodium sulphate. After evaporation
of the solvent under reduced pressure, 11.5 9 of a yellow oil
are obtained.
The lower phosphoric phase is poured over 3 volumes
of crushed ice. This solution is shaken twice with ether at
room temperature.
The ethereal phases are shaken in the presence of 5%
soda and, after decantation of the aqueous phase, they are
neutralized and dried over sodium sulphate. After evaporation
of the solvent under reduced pressure, 5 g of a yellow oil are
obtained.
The two oily fractions are combined and distilled
under reduced pressure. 12 g of ketone are obtained in the
form of a colourless liquid with a boiling point of 105-108C
at 0.02 mm. Hg.
B - 7-chloro-3,4-dihydro-1-benzoxepin-5-one oxime:
A solution of 50 9 of the benzoxepinone previously
obtained and 26 g of hyclroxylamine hydrochloride in 200 ml of
pyridine is kept at the reflux temperature of pyridine for 5
-- 4
Z6
hours.
The pyridine is then evaporated off under reduced
pressure, 300 ml of water are poured over the evaporation
residue and the aqueous phase is extracted three times with
ether. The organic solutions are washed with water until the
wash waters arP neutral and dried over sodium sulphate and then
over magnesium sulphate and the solvent is evaporated off under
reduced pressure.
The evaporation residue is recrystallized from abso-
lute ethanol. 47 g of pure oxime, a white product which meltsat 101-102C, are obtained.
C - 7-chloro-3,4-dihydro-1-benzoxepin-0-(dimethylaminoethyl)-5-
one oxime
7.1 9 of the oxime previously obtained are introduced
into 30 ml of a solution of sodium ethylate in ethanol (pre-
pared with 0.9 9 of sodium). The reaction mixture is heated at
the reflux temperature of the solvent for 1 hour. 50 ml of
anhydrous dimethylformamide are then introduced and the ethanol
is evaporated off under reduced pressure. 4 g of (2-chloro)-
ethyl dimethylamine are added and the mixture is kept at 80Cfor 6 hours. It i5 then cooled, the mineral salts are filtered
and the solvent is evaporated under reduced pressure.
The residue is dissolved in a normal aqueous solution
of hydrochloric acid and, after extraction with ether, the
solution is made alkaline by the addition of a normal soda
solution. The oxime ether is then extracted in methylene
chloride, and the solvent is evaporated off after drying.
The oily residue is dissolved in ether and the amine
hydrochloride is precipitated from the resulting solution by
the addition of hydrochloric acid. The hydrochloride is
recrystallized from a mixture of ethyl acetate and isopropanol
(75 : 25). It melts at 180C.
~04~8~;26
The yield of this stage is 40%.
EXAMPLE 2
7-chloro-3,4-dihydro-1-benzoxepin-0-(diethylaminoethyl)-5-one
oxime: isomer with the c~s configuration in relation to the
benzene nucleus.
1.2 g of 50% sodium hydride are added slowly with
stirring and slight cooling to a solution of 5 g of 7-chloro-
3,4-dihydro-1-benzoxepin-5-one oxime in 25 ml of anhydrous
dimethyl-formamide. This sodium salt may also be prepared by
reaction with sodium ethylate in ethanol followed by dissolving
in dimethylformamide.
After one hour's stirring at room temperature, 3.1 9
of (2-chloro)-ethyl diethylamine are introduced into the
reaction mixture in the course of 15 minutes. One hour later,
200 ml of water are added and the final reaction product is
extracted with ether. It is then extracted from the ether with
a 5% solution of acetic acid. The aqueous phase is made alka-
line by the addition of K2C03 and the amine is again extracted
with ether.
After drying of the organic solution, the solvent is
evaporated and the oily residue is distilled under reduced
pressure.
The boiling point of the basic oxime ether finally
obtained is 137C at 2 x 10 2 mm. Hg.
The yield of distilled amine is 60%.
Its hydrochloride prepared in ether is recrystallized
from a mixture of isopropyl ether and l,2-dichloroethane
(60 : 40). It melts at 115 - 116C.
This salt also can be recrystallized from ethyl
acetate but, if it is subjected to prolonged heating in the
course of this operation, another crystalline form of the
product appears, which has a melting point of 132C.
-- 6
~L~14~216i
The geometric isomer of this oxime ether, which has
the ~s configuration in relation to the benzene nucleus, may
advantageously be separated from traces of its trans homologue
in the form of its acid addition salt with hydrobromic acid by
recrystallisation from isopropanol. The hydrobromide melts at
ll~C
EXAMPLE 3
7-chloro-3,4-dihydro-1-benzoxepin-0-(diethylaminoethyl)-5-one
oxime: tYans isomer
A solution of 50 9 of 7-chloro-3,4-dihydro-1-benz-
oxepin-5-one oxime in 800 cc of anhydrous chloroform is satu-
rated with anhydrous hydrochloric acid and the mixture is
continuously stirred at 20C for about 24 hours. The precipi-
tate formed is then isolated and the filtrate is twice brought
into contact with a saturated aqueous sodium bicarbonate
solution and then with water until neutral. The organic phase
is dehydrated with sodium sulphate and the solvent is evapo-
rated under reduced pressure. The evaporation residue is
recrystallised from cyclohexane. 40 9 of a product melting in
the region of 95C are obtained. The product consists of a
mixture of nearly equivalent proportions of the two geometric
isomers of the oxime.
The geometric isomer which has the trans configur-
ation in relation to the benzene nucleus can be separated from
its homologue by subjecting the mixture to chromatography on a
silica column, using diethyl ether as the eluent. The trans
isomer melts at 150C after recrystallisation from isopropanol.
0-alkylation of the 50/50 mixture of the two isomers
is carried out in dimethylformamide, using the method described
in example 2. The crude amine obtained consists of nearly the
same proportions of isomers as the starting material.
Z6
The hemifumarate of the amine function is then pre-
pared as follows: 11.45 9 of the oil obtained are dissolved in
50 ml of ethanol, and 4.3 9 of fumaric acld are added. The
solution is heated at reflux for 1/4 of an hour and then
conled, and one volume of diethyl ether is added. The precipi-
tate obtained is isolated. It consists to an extent of at
least 90% of the isomer which has the eis configuration in
relation to the benzene nucleus. The filtrate is made alkaline
by the addition of sodium carbonate. The ethanol is then
evaporated off under reduced pressure and the desired product
is obtained in the form of the amine by extraction with diethyl
ether. After drying of the solutiong the amine hydrochloride
is prepared by the addition of anhydrous hydrochloric acid.
The precipitate is filtered and dried. It is then purified by
preparing solutions of this hydrochloride in a solvent at 25C,
preferably ethanol, and then reprecipitating the product by the
addition of diethyl ether. 1.5 9 of the hydrochloride of the
t~ans isomer of 7-chloro-3,4-dihydro-1-benzoxepin-0-(diethyl-
aminoethyl)-5-one oxime is thereby obtained, which melts at
144C.
Examples 4 and 5 illustrate two other methods of
preparation of the product described in example 2.
EXAMPLE 4
Preparation of 7-chloro-3,4-dihydro-1-benzoxepin-0-(diethyl-
aminoethyl)-5-one oxime from 7-chloro-3,4-dihydro-1-benzoxepin-
5-one and 0-(diethylaminoethyl)-hydroxylamine:
10.25 9 of the dihydrochloride of 0-(diethylamino-
ethyl)-hydroxylamine are added to a solution of 19.65 9 of 7-
chloro-3,4-dihydro-1-benzoxepin-5-one in 100 ml of absolute
ethanol, and the reaction mixture is heated to the reflux
temperature of the solvent for 5 hours. After 11 hours under
reflux, a further 10.25 9 of the dihydrochloride of 0-(diethyl-
~.~48~26
aminoethyl)-hydroxylamine are added to the reaction mixture.
The solvent is then evaporated under reduced pressure
and a dilute solution of hydrochloric acid is poured over the
residue. The aqueous phase obtained is washed with ether and
then made alkaline by the addition of sodium carbonate.
The final product is extracted with ether. The
organic phase is dried over sodium sulphate and the magnesium
sulphate and the solvent is evapora~ed under reduced pressure.
13.9 9 of oil are obtained.
The hydrochloride of the end product is prepared in
ether by the action of gaseous hydrochloric acid. After
recrystallisation from a mixture of isopropyl ether and 1,2-
dichloroethane (60: 40) in the presence of animal charcoal,
10.5 g of the hydrochloride of the desired product are obtained
in the form of white crystals melting at 115 - 116C.
The hemifumarate of the end product is prepared in
ethanol by adding an equimolecular proportion of fu~aric acid
to the amine solution, and is precipitated from this reaction
medium by the addition of petroleum ether. After recrystalli-
20 sation, from a mixture of isopropanol and isopropyl ether(50: 50), the pure hemifumarate melts at 98C.
EXAMPLE 5
Preparation of 7-chloro-3,4-dihydro-1-benzoxepin-0-(diethyl-
aminoethyl)-5-one oxime from 7-chloro-3,4-dihydro-1-benzoxepin-
5-one oxime: _ _
A mixture of 5.3 g of 7-chloro-3,4-dihydro-1-benz-
oxepin-5-one oxime, 4~3 g of the hydrochloride of (2-chloro)-
ethyl diethylamine, 10.7 g of potassium carbonate and 50 ml of
benzene is kept at the reflux temperature of the solvent for
30 15 hours. The mineral precipitate is then filtered and the
benzene phase is washed with a normal aqueous soda solution and
the end product is extracted with a normal aqueous solution of
~al4~Z6
hydrochloric acid. After washing with ether, the aqueous phase
is made alkaline by the addition of sodium carbonate and the
end product is extracted with ether. After dehydration of the
solution and evaporation of the solver,t, 7.8 9 of a yellow oil
are obtained from which 6.3 9 of the desired hydrochloride of
the basic oxime ether are prepared. Melting point of the
hydrochloride: 115 - 116C.
EXAMPLE 6
7-chloro-3,4-dihydro-1-benzoxepin-0-(morpholinoethyl)-5-one
oxime
11 g of this compound are obtained from 7.6 9 of 7-
chloro-3,4-dihydro-1-benzoxepin-5-one oxime and 6 g of N-(2-
chloroethyl)-morpholine by the method of preparation described
in example 1.
The hydrochloride prepared in hydrochloric ether and
recrystallised from ethyl acetate melts at 140C.
EXAMPLE 7
7-chloro-3,4-dihydro-1-benzoxepin-0-(1-pyrrolidinyl-ethyl)-5-
one oxime __
16.3 9 of the dihydrochloride of 0-(1-pyrrolidinyl-
ethyl)-hydroxylamine (Mp = 150C) and a few drops of concen-
trated hydrochloric acid are added to 15.7 9 of 7-chloro-3,4-
dihydro-l-benzoxepin-5-one dissolved in 100 ml of 95% ethanol,
and the reaction mixture is heated at the reflux temperature of
the solvent for 6 hours.
The solvent is evaporated off under reduced pressure
and the residue is taken up with normal hydrochloric acid,
unreacted ketone is extracted with ether, the aqueous phase is
made alkaline by the addition of sodium carbonate, and the
amine end product is extracted with benzene.
The solution in benzene is copiously washed with
water and then dried over magnesium sulphate and the solvent is
- 10 -
1(D4~3~)Z~i
evaporated off under reduced pressure.
The hydrochloride of the amine is prepared in hydro-
chloric ether and then recrystallised from isopropanol. It
melts at 154 - 155C. The yield based on the ketone is 45%.
EXAMPLE 8
7-chloro-3,4-dihydro-1-benzoxepin-0-(dimethylaminopropyl)-5-one
oxime
-
Applying the method of preparation described in
example 1 and reacting 7.6 9 of oxime and 4.9 9 of (3-chloro)-
10 propyl dimethylamine at stage (C), 7 9 of crude end product areobtained in the form of an oil.
The hydrochloride prepared in hydrochloric ether
melts at 166C after recrystallisation from isopropanol.
EXAMPLE 9
7-methoxy-3,4 dihydro-1-benzoxepin-0--(dimethylaminoethyl)-5-one
oxime
-
A - 7-methoxy-3,4-dihydro-1-benzoxepin-5-one
40 ml of concentrated phosphoric acid (d - 1.71) are
added to 300 ml of anhydrous toluene. 70 9 of phosphorus
20 pentoxide are then slowly added with vigorous stirring. The
mixture is kept on a boiling water bath for 2 hours. A tepid
solution of 20 9 of p-methoxyphenoxybutyric acid (Mp = 104C)
in 1 litre of anhydrous toluene is then added at this temper-
ature in the course of 2 hours. The mixture is kept on the
boiling water bath for a further 3 hours and then cooled. The
upper toluene phase is decanted and the lower phase is poured
over 2 volumes of crushed ice. When the whole mixture has ad-
justed to room temperature, the organic products are extracted
with ethyl acetate. After washing this phase with water and
30 then with a solution of sodium bicarbonate and neutralising, it
is dried over magnesium sulphate and the solvent is evaporated
under reduced pressure. 15.4 9 of an oil are obtained which
~48~Z6
after distillation yields 12 9 of 7-methoxy-3,4-dihydro-1-benz-
oxepin-5-one which has a boiling point of 110C at 0.02 mm. Hg.
B - 7-methoxy-3,4-dihydro-1-benzoxepin-5-one oxime
6.95 g of hydroxylamine hydrochloride dissolved in
15 ml of water and 5.3 9 of sodium carbonate are added to a
solution of 19.2 9 of 7-methoxy-3,4-dihydro-1-benzoxepin-5-one
in 45 ml of ethanol. The mixture is stirred for 24 hours at
room temperature. 100 ml of water are then added and the alco-
hol is evaporated. The aqueous solution is made alkaline by
the addition of soda, and unreacted benzoxepinone is extracted
with ether. The aqueous phase is neutralised and the desired
oxime is extracted with ether. After drying the organic
solution and evaporating the solvent under reduced pressure, a
white solid is obtained which when recrystallised from cyclo-
hexane yields 17 9 of the desired product in the pure form
which has a melting point of 103 - 104C.
C - 7-methoxy-3,4-dihydro-1-benzoxepin-0-(dimethylaminoethyl)-
5-one oxime
5.84 g of the oxime prepared as indicated above are
added to 30 ml of a solution of sodium ethylate prepared from
0.8 9 of sodium, and the mixture is heated on a boiling water
bath for 1 hour. 30 ml of anhydrous dimethylformamide are then
added and the alcohol is evaporated under reduced pressure.
3.2 9 of (2-chloro)-ethyl dimethylamine are added
and the reaction mixture is kept on a boiling water bath -For
1 hour.
The solvent is evaporated under reduced pressure and
the residue is taken up with an aqueous 10% hydrochloric acid
solution. This phase is washed once with ether and made alka-
line by the addition of 10% soda.
The end product is extracted with methylene chloride,the organic phase is dried and the solvent is evaporated under
h8~
reduced pressure. The oil obtain d is distilled. Boiling
point: 160C at 0.5 mm. Hg.
4.1 9 of the amine end product are obtained. The
hydrochloride prepared in hydrochloric ether and recrystallised
from isopropanol melts at 178C.
EXAMPLE 10
7-methoxy-3,4-dihydro-1-benzoxepin-0-(diethylaminoethyl)-5-one
oxime
Applying the method of preparation described in
example 9 and reacting 7.25 9 of oxime and 6.8 9 of (2-chloro)-
ethyl diethylamine at stage (C), 7 9 of the crude amine end
product are obtained.
The hydrochloride prepared in hydrochloric ether
melts at 180C after recrystallisation from ethyl acetate.
EXAMPLE 11
7-methoxy-3,4-dihydro-1-benzoxepin-0-(dimethylaminopropyl)-5-
one oxime
Applying the method of preparation described in
example 9 and reacting 5.85 9 of oxime and 4 9 of (3-chloro)-
propyl dimethylamine at stage (C), 6.2 9 of the amine end
product are obtained in the form of a yellow oil.
The hemioxalate of the amine is prepared in ethanol
by reacting the amine and acid in equimolecular proportions.
After recrystallisation from ethanol, the pure hemioxalate
melts at 130C.
EXAMPLE 12
7-bromo-3,4-dihydro-1-benzoxepin-0-(diethylaminoethyl)-5-one
oxime
-
A - 7-bromo-3,4-dihydro-1-benzoxepin-5~one:
This heterocyclic ketone is prepared with a 40% yield
from p-bromophenoxy butyric acid (Mp - 132C) by the method
described in example 1 (A). Its boiling point is 105C at 0.06
- 13 -
8~
mm. Hg.
B - 7-bromo-3,4-dihydro-1-benzoxepin-0-(diethylaminoethyl)-5-
one oxime
The amine is prepared by reacting the benzoxepinone
previously obtained with the dihydrochloride of 0-(diethyl-
aminoethyl) hydroxylamine by the method of operation described
in example 4. 4.5 g of end product are obtained in the form of
an oil from 7 g of 7-bromo-3,4-dihydro-1-benzoxepin-5-one.
The hydrochloride of this amine is prepared in ether
by the action of gaseous hydrochloric acid and purified by dis-
solving it in ethanol and then reprecipitating it by the
addition of ethyl ether. It melts at 138C.
The yield of hydrochloride from the ketone is 50%.
Toxicological and pharmacological studies of the
products of the invention demonstrated the originality of their
activity compared with known products. The tests were carried
out on acid addition salts of the amines of the general
formula.
The acute toxicity was determined on male mice of the
strain Swiss C.D weighing on average 20 grammes, after oral
administration (P.0) and intravenous administration (I.V).
The relaxant action at the level of the smooth
intestinal muscle fibre was demonstrated in vitro on the
isolated organ and in vivo on the anaesthetised dog by applying
the following techniques:
For the tests on the isolated organ: an organ
fragment of rat duodenum or guinea pig ileum is kept alive in
50 ml of an oxygenated and thermostatically controlled (37C)
tyrode solution. The activity of the compounds is tested on
the spontaneous movement of the organ and on the contractions
produced by the addition of a solution of barium chloride or
acetyl choline to the bath. The movements were recorded on a
- 14 -
DMP 4A Roucaire physiograph.
For the in vivo tests: a small balloon is introduced
at the level of the terminal part of the duodenum in the
chloralosed animal and the intestinal movements are recorded on
a Beckman polygraph with the aid of a Statham PM 97 gauge.
The results relating to the acute toxicity and to the
relaxant activity in vi~ro are shown in table 1.
The in vivo tests showed that the products of the
invention and in particular those of examples 1, 2, 7, 8 and 12
administered intravenously in a dose of 2 mg/kg had an effect
which was comparable with or even superior to that of atropine
administered in a dose of 50 mg/kg as regards the reduction in
intestinal tone and peristalsis. In contrast to atropine,
however, this relaxant activity is produced without any anti-
cholinergic or vagolytic activity.
Pharmaceutical compositions containing as active
ingredient at least one product according to the invention may
be presented, for example, in the form of tablets or injection
solutionsO
The tablets may contain about 75 mg of active
ingredient and known excipients such as microcrystalline cellu-
lose, carboxymethyl starch, talcum and magnesium stearate.
The injection ampoules may contain about 25 mg. of
active ingredient and a sufficient quantity of glycine to
render the product isotonic.
- 15 -
TABLE I
C O M P O U N D TOXICITY in miceISOLATED ORGANS:
LD = (mg/kg)Minimum active dose
of 50 Concentration in mcg/ml
______ _ __ _ __ ___ __
example P.O I.V DECONTRACTION ANTI-ACETYL
(rat duodenum) C~IOLINE
(guinea pig
1150 32 0.06 5.5
10 (hydrochloride)
2420 37 0.1
(hydrochloride)
6> 1000 120 0.15 5.5
(hydrochloride)
7450 35 1.5 1.3
(hydrochloride)
8500 60 0.12 3.5
(hydrochloride)
9500 35 0.12 1.5
20 (hydrochloride) .
10450 45 0.5 0.5
(hydrochloride)
11> 1000 _ 0.3 2.0
(hemioxalate)
12250 40 0.1
(hydrochloride) _
ATROPINE 600 90 inactive 0.006
(sulphate) _
- 16 -