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BACKGROUND OF THE INVENTION
French Patent Application 2,464,270 describes compounds of the
14-aminosteroid type, in particular hydroxylated derivatives of
14-aminoandrostane and of 14-amino-21-norpregnane. Steroid alkaloids of
the pregnane and androstane series, substituted in the 14-position by an
amino group, are also known; for example,
14.beta.-aminopregnane-3.beta.,20.alpha.-diol is described by A. Astier et
al., Bull. Soc. Chim. no. 9-10, pages 1581-1582 (1976); other
14.beta.-aminopregnanes and 14.beta.-aminoandrostanes are also described
by A. Astier et al., Tetrahedron, Volume 34, pages 1481-1486 (1978).
However, neither pharmacological properties nor therapeutic applications
have been described for these derivatives.
French Patent Application 2,494,697 describes
3-amino-(5.alpha.)-pregnane-17.alpha.,20-diol and
3-amino-(5.alpha.)-19-norpregnan-20-ol, which are presented as possessing
immunotherapeuti properties enabling them to be applied as medicaments for
treating autoimmune diseases resulting from a deficiency in certain
lymphocytes.
SUMMARY OF THE INVENTION
The studies carried out by the Applicant Company have made it possible to
establish, surprisingly, that 14-aminosteroids, and more particularly
derivatives of the pregnane-3,20-diol and pregnane-3,12,20-triol type
substituted in the 14-position by an amino group, possess positive
inotropic properties.
The present invention therefore relates to new medicaments based on
14-aminosteroids, possessing, in particular, a positive inotropic activity
enabling them to be applied as cardiotonic medicaments for treating
cardiac insufficiencies.
The invention also relates, by way of new products, to 14-aminosteroids of
the 14-aminopregnane-3,20-diol, 14-aminopregnane-3,12,20-triol and
14-amino-21-norpregnane-3,12,20-triol series, and also to a process for
their preparation.
The new medicaments according to the present invention contain, as active
principle, a 14-aminosteroid represented by the general formula (I) below:
##STR1##
in which R represents a hydrogen atom or a lower alkyl group containing 1
to 4 carbon atoms, for example a methyl group, an ethyl group or an
isopropyl group, and R.sub.1 represents a hydrogen atom or a hydroxyl
group.
The invention also relates to the pharmaceutically acceptable salts of the
14-aminosteroids of the general formula (I), obtained by reaction with a
mineral or organic acid in accordance with the methods customary in the
art. The acid used can be chosen from amongst hydrochloric acid, oxalic
acid, tartaric acid, fumaric acid, lactic acid, phosphoric acid,
p-toluenesulfonic acid, formic acid, hydrobromic acid, maleic acid,
sulfamic acid and the like.
The invention also relates to the new 14-amino-steroids represented by the
general formula (I) above in which R represents a hydrogen atom or a lower
alkyl group having 1 to 4 carbon atoms and R.sub.1 is a hydrogen atom or a
hydroxyl group, R and R.sub.1 not being a hydrogen atom simultaneously,
and also to their salts with acids.
DETAILED DESCRIPTION OF THE INVENTION
The 14-aminosteroids of the general formula (I) contain, in their molecule,
several asymmetric carbon atoms, in particular the carbons in the 3-, 5-,
14-, 17-and 21- positions, and can therefore exist in various
stereoisomeric forms, it being understood that the new compounds according
to the invention can be any one of these stereoisomers in the case where
R.sub.1 is a hydroxyl group, whereas in the case where R.sub.1 is a
hydrogen atom, they consist of the stereoisomers in which, when the OH
group in the 3-position and the NH.sub.2 group in the 14-position have the
.beta. configuration and when the hydrogen atom in the 17-position
possesses the .alpha. configuration, irrespective of whether the hydrogen
atom in the 5-position has the .alpha. or .beta. configuration, the OH
group in the 20-position has the .beta. configuration.
The invention relates more particularly to the 14-aminosteroids represented
by the general formula (I) above in which R is a methyl group. In this
formula, the --NH.sub.2 group in the 14-position and the hydrogen atom in
the 5-position can have the .alpha. or .delta. configuration, preferably
the .beta. configuration. Likewise, the --CHROH group in the 17-position
can have the 17.alpha. or 17.beta. configuration. The --OH group in the
3-position and the --OH group represented by R.sub.1 preferably have the
.beta. configuration. When R is not a hydrogen atom, the --OH group in the
20position can have the .alpha. or .beta. configuration, and in the case
where R.sub.1 is a hydrogen atom, it preferably has the .beta.
configuration. Of course, the invention relates to these various isomers,
in isolation or in a mixture. In accordance with the customary
nomenclature, unless otherwise indicated, the hydrogen atoms in the 5- and
17-positions occupy the .alpha. configuration in the examples below.
The compounds of the general formula (I) can be prepared from the
3,14-dihydroxysteroids of the general formula (II) below:
##STR2##
in which R represents a hydrogen atom or a lower alkyl group having 1 to 4
carbon atoms and R.sub.1 represents a hydrogen atom or an alkyl group, by
means of a reduction reaction followed by an acetylation to form the
3,14,20-trihydroxysteroids 0-acetylated in the 3- and 20-positions, and in
the 12-positions when R.sub.1 is a hydroxyl group, if the general formula
(III) below:
##STR3##
in which R is a hydrogen atom or a lower alkyl group having 1 to 4 carbon
atoms, R.sub.1 is a hydrogen atom or an acetyl group and Ac is an acetyl
group, and by reaction with a hydrazoic acid/boron trifluoride complex to
form the corresponding 14-azido derivative, and then by means of a
reduction with a metal hydride or by catalytic hydrogenation.
The first step, consisting in carrying out a reduction followed by an
acetylation to form a di-0-acetylated trihydroxysteroid when R.sub.1 is a
hydrogen atom or a tri-0-acetylated tetrahydroxysteroid when R.sub.1 is a
hydroxyl group, can be carried out, for example, by means of a hydride in
accordance with the technique described by J. Fried and J. A. Edwards,
"Organic Reactions in Steroid Chemistry", published by Van Nostrand
Reinhold (1972). It is possible, for example, to use double hydrides of
aluminum or boron, such as sodium borohydride or lithium aluminum hydride,
or alternatively other reducing agents such as hydrogen in the presence of
catalysts.
the acetylation reaction making it possible to obtain the acetylated
steroid of the general formula (III) can be carried out in accordance with
the customary techniques, for example by reaction with acetic anhydride in
an organic solvent.
In the second step, the derivative of the general formula (III) is
converted to the corresponding 14azido derivative by reaction with a
solution of a hydrozoic acid/boron trifluoride complex in benzene. The
replacement of the hydroxyl group in the 14-position by a tertiary azide
group takes place with a good yield, the other hydroxyl groups in the
3-position , 12-position (if appropriate) and 20-position having been
protected beforehand by acetylation.
The third step, consisting in converting the 14-azido derivative to the
corresponding 14amino derivative, can be carried out by catalytic
hydrogenation followed by removal of the acetyl protecting groups, or by
reaction with a reducing agent such as a metal hydride, and more
particularly lithium aluminum hydride, to form the 14-aminosteroid of the
formula (I).
The starting ketones represented by the general formula (II) can be
prepared by applying the method described by N. Danielli et al.,
Tetrahedron, 22, page 3189 (1966). For example, when R.sub.1 is a hydroxyl
group, a 3,12-diacetoxy-14-hydroxyetianic acid can be treated with an
organometallic compound such as methyl-lithium; the reaction can be
advantageously be carried out be gradually adding a solution of
methyl-lithium in ether, at a temperature below 10.degree. C., to a
solution of 3,12-diacetoxy-14-hydroxy-5.beta.-etianic acid in
tetrahydrofuran, in the presence of sodium hydride. In the case of the
preparation of the derivatives in which R is hydrogen, the reaction can
also be carried out directly with a reducing agent such as lithium
aluminum hydride. The etianic acid derivative used as the starting
material is described in the Literature (D. Taylor, J. Chem. Soc., 1953,
page 3325). When R.sub.1 is a hydrogen atom, a 3-acetoxy-14hydroxyetianic
acid is treated in the same manner with an organometallic compound.
The 14-aminosteroids of the general formula (I) in which R and R.sub.1
represent a hydrogen atom can also be prepared by the process described in
French Pat. No. 2,464,270. Likewise, the method of preparation described
by Astier et al., Bull. Soc. Chin., no. 9-10, pages 1581-1582 (1976) can
also be applied in order to obtain the 14-aminosteroids of the general
formula (I) in which R is a lower alkyl group and, more precisely, a
methyl group.
The process according to the present invention makes it possible to
prepare, under satisfactory conditions, the various stereoisomeric forms
of the 14-amino-steroid derivatives represented by the general formula
(I), in particular the derivatives in which the hydroxyl groups in the
3-position and 12-position (if appropriate) and the hydrogen atom in the
5-position have the .beta. configuration, the amino group in the
14-position preferably possessing the .beta. configuration, while the
hydroxyl group in the 20-position can have either the .alpha. or .beta.
configuration when R is an alkyl group.
The examples described below illustrate the invention without limiting its
scope. The structures of the products obtained were verified by their
infra-red spectra, NMR spectra and mass spectra.
EXAMPLE 1
(a) Preparation of 3,20-di-0-acetyl-5.beta.-pregnane-3.beta.,14.beta.,
20-triol
6 g of 20-oxo-5.beta.-pregnane -3.beta.,14.beta.-diol,obtained by the
method of N. Danielli et al. (mentioned above), are dissolved in 30 ml of
methanol, 1.5 g of potassium borohydride are then added in portions and
the reaction is left to proceed for about 30 minutes. The methanol is
removed by evaporation, the residue is extracted with ethyl acetate and
the extract is washed. The residue is treated with 16.5 ml of acetic
anhydride in 35 ml of pyridine overnight. After hydrolysis and washing
with citric acid and water, a residue is obtained (7 g, that is to say a
yield of 95%) comprising the two isomers 20.alpha. and 20.beta., which are
separated by chromatography on a silica column. (b) Preparation of
14.beta.-amino-5.beta.-pregnane-3.beta.,20.alpha.-diol
210 mg of the 20.alpha. isomer of the diacetyltriol obtained as indicated
above are dissolved in a solution of 16.5 ml of hydrozoic acid in benzene,
the mixture is stirred for 5 minutes and 0.4 ml of freshly distilled boron
trifluoride etherate reagent is then added. After a reaction time of 10
minutes, the reaction mixture is poured into a mixture of crushed ice and
aqueous ammonia solution.
Extraction is carried out with benzene, the extract is washed and dried,
the residue is then dissolved in 20 ml of tetrahydrofuran, and 54 mg of
lithium aluminum hydride are added. After heating under reflux for 1 hour,
the mixture is hydrolyzed and a neutral fraction of 80 mg and a basic
fraction of 77 mg of aminopregnane-diol (yield 49%) are extracted. Melting
point m.p.=258.degree. C.
EXAMPLE 2
14.beta.-Amino-5.beta.-pregnane-3.beta.,20.beta.-diol
9 g of the 20.beta. isomer of the diacetyltriol prepared as indicated in
Example 1 a) are dissolved in 600 ml of a benzene solution of hydrozoic
acid and the boron trifluoride etherate is then added after a reaction
time of 5 minutes, the same treatment as in Example 1 B) being carried
out.
This gives 2.3 g of 14-amino-5.beta.-pregnane-3.beta.,20.beta.-diol (yield
32%). Crystallization is carried out from ethyl acetate.
Melting point m.p.=196.degree. C.
IR spetrum (Nujol).nu.=3600 to 2100, 1585, 1030 cm.sup.-1
EXAMPLE 3
14.alpha.-Amino-5.beta.-pregnane-3.beta.,20.alpha.-diol
The procedure indicated in Example 1 is followed. The desired product is
isolated from its 14.beta.-amino-5.beta.-pregnane-3.alpha.,20.alpha.-diol
isomer by chromotagraphy, on a silica column, of the mother liquors from
crystallization of the main product. Crystallization is carried out from a
mixture of ethyl acetate and methanol. Melting point m.p.=188.degree. C.
EXAMPLE 4
14.alpha.-Amino-5.beta.-pregnane-3.beta., 20.alpha.-diol
The procedure of Example 2 is followed. The desired product is isolated by
chromtography, on a silica column, of the mother liquors from
crystallization of the
14.beta.-amino-5.beta.-pregnane-3.beta.,20.beta.-diol isomer.
The product is crystallized from isopropanol. Melting point
m.p.=216.degree. C.
EXAMPLE 5
14.beta.-Amino-5.beta.,17.beta.H-pregnane-3.beta.,20.alpha.-diol
0.5 g of 20-oxo-5.beta.,17.beta.H-pregnane-3.beta.,14.beta.-diol is reduced
with 120 mg of potassium borohydride in 3 ml of methanol. After the
reaction, an acetylation is carried out with axetic anhydride in pyridine,
in accordance with the customary techniquies, to give di-O-acetyl-5.beta.,
17.beta.H-pregnane-3.beta.,14.beta.,20.alpha.-triol with a yield of 95%.
0.4 g of the diacetyltriol obtained as indicated above is dissolved in 30
ml of a benzene solution of hydrozoic acid, and 0.6 ml of boron
trifluoride etherate is then added. After treatment as in Example 1, 0.1 g
of lithium aluminum hydride is reacted with the residue in 10 ml of
tetrahydrofuran. After hydrolysis, extraction and crystallization from
ethyl acetate, 0.25 g (yield 80%) of
14.beta.-amino-5.beta.,17.beta.H-pregnane-3.beta.,20.alpha.-diol is
obtained.
Melting point m.p.=200.degree.-201.degree. C.
EXAMPLE 6
14.beta.-Amino-5.alpha.-pregnane-3.beta.,20.alpha.-diol
The procedure of Example 1 is followed using the 5.alpha. isomer, the
reaction with the boron trifluoride etherate being left to proceed for
about 5 hours.
After treatment and reduction with lithium aluminum hydride as in Example
1, the residue is taken up in ethyl acetate and the mixture is then washed
with a 10% hydrochloric acid solution. Then, the acetate is removed by
evaporation and the acid phases are neutralized with sodium carbonate and
extracted with chloroform. After filtration, the filtrate is dried and,
after crystallization from ethyl acetate, gives
14.beta.-amino-5.alpha.-pregnane-3.beta.,20.alpha.-diol with a yield of
more than 50%.
Melting point m.p.=246.degree. C.
EXAMPLE 7
14.beta.-Amino-5.alpha.-pregnane-3.beta.,20.beta.-diol
The procedure of Example 1 (a) is followed using the 5.alpha. isomer of the
starting pregnanediol, and the 20.beta. isomer of the diacetyltriol
obtained is isolated.
the same treatment as in Example 1 (b) is then applied; this gives
14.beta.-amino-5.alpha.-pregnane-3.beta.,20.beta.-diol, which is
recrystallized from diisopropyl ether.
Melting point m.p.=213.degree. C.
EXAMPLE 8
14.beta.-Amino-21-nor-5.beta.-pregnane-3.beta.,20-diol
This compound is prepared as indicated in Example 6 of French Pat. No.
2,464,270 in the name of the Applicant Company.
EXAMPLE 9
14.beta.-Amino-5.beta.-pregnane-3.beta.,12.beta.,20.beta.-triol
1.1 g of lithum aluminum hydride is added, while keeping the temperature at
0.degree. C., to a solution of 130 ml of tetrahydrofuran containing 8 g of
a mixture of 20-oxo-5.beta.-pregnane-3.beta.,12.beta.,14.beta.-triol and
corresponding 0-acetylated derivatives, the mixture having been obtained
by reacting a solution of methyl-lithium in ether with
3.beta.,12.beta.-diacetoxy-14.beta.-hydroxy-5.beta.-etianic acid in
tetrahydrofuran, in the presence of sodium hydride, at a temperature below
about 10.degree. C., under a nitrogen atmosphere.
Ethyl acetate is added in the cold, followed by a mixture of
tetrahydrofuran and water. After filtration and evaporation of the
solvent, 7.6 g of
5.beta.-pregnane-3.beta.,12.beta.,14.beta.,20.epsilon.-tetrol are
collected in the form of a colorless powder.
The above product is dissolved in 120 ml of methylene chloride, and 9.2 ml
of acetic anhydride and 1.2 g of 4-dimethylaminopyridine are added to the
solution. The reaction mixture is stirred for a few hours and then washed
with a solution of sodium carbonate, and the aqueous phase is extracted
with methylene chloride. After drying, 9.3 g of
3,12,20-tri-0-acetyl-5.beta.-pregnane-3.beta.,12.beta.,14.beta.,20.epsilon
.-tetrol are obtained.
The two isomers 20.alpha. and 20.beta. are separated by chromatograpy on
Merck H60 silcia using a mixture of methylene chloride and acetone
(96.5/3.5) as the eluent.
The
3,12,20-tri-0-acetyl-5.beta.-pregnane-3.beta.,12.beta.,14.beta.,20.beta.-t
etrol is recrystallized from ether (melting point m.p.=216.degree. C.). 5.7
g of this product are dissolved in 330 mg of an approximately 10 M benzene
solution of hydrozoic acid, 7.3 ml of freshly distilled boron trifluoride
etherate are then added and the mixture is stirred for about 25 minutes.
After alkalisation with a mixture of aqueous ammonia and crushed ice,
extraction with benzene, washing with water, drying over sodium sulfate
and evaporation, 5.8 g of a residue are obtained, which is dissolved in
300 ml of ethanol. The solution is hydrogenated at ambient temperature,
under a hydrogen atmosphere, for 48 hours, in the presence of 2.9 g of
palladium-on-calcium carbonate (5% strength).
The catalyst is removed by filtration and the filtrate is evaporated to
dryness to give 5.5 g of a colorless foam, which is dissolved in toluene.
The solution is washed several times with a 5% strength solution of
sulfamic acid. The precipitate formed is filtered off and purified to give
0.5 g of 3,
12,20-tri-0-acetyl-14.beta.-amino-5.beta.-pregnane-3.beta.,12.beta.,20.bet
a.-triol. The acid aqueous phases are rendered alkaline with sodium
carbonate and extracted with methylene chloride to give 0.75 g of the same
product.
Melting point m.p.=211.degree. C. (isopropyl ether)
0.2 g of
3,12,20-tri-0-acetyl-14.beta.-amino-5.beta.-pregnane-3.beta.,12.beta.,20.b
eta.-triol, obtained as indicated above, is saponified in 150 ml of a 1N
methanolic solution of sodium hydroxide by stirring the suspension for 2
hours at ambient temperature and then heating it under reflux for 30
minutes.
After the solvent has been evaporated off, the residue is extracted with
chloroform. This give 0.15 g of
14.beta.-amino-5.beta.-pregnane-3.beta.,12.beta.,20.beta.-triol, which can
be recrystallized from a mixture of ethyl acetate and methanol.
Melting point m.p.=238.degree. C.
IR spectrum (Nujol) .nu.=3400, 3330, 3270, 3180, 3100, 2660,1615, 1600
cm.sup.-1
The 14-aminosteroids according to the invention, represented by the general
formula (I) above, possess valuable pharmacological properties and, more
particularly, they possess a positive inotropic activity.
These properties, which are illustrated below, show that the
14-aminosteroids of the general formula (I) and also their
pharmaceutically acceptable salts can be used in human and veterinary
therapy as medicaments for treating cardiac insufficiency.
The toxicological experiments carried out showed that the acute toxicity of
the 14-aminosteroids according to the invention was relatively low and, in
particular, considerably lower than that of the customary digitalis-based
compounds such as digitoxin and digoxin.
The inotropic effect in vitro was demonstrated on isolated guinea-pig heart
in accordance with Langendorff's method and on isolated guinea-pig
auricle. The results obtained show that the 14-aminosteroids according to
the invention can be applied in the treatment of cardiac insufficiency.
By way of example, in the case of
14.beta.-amino-5.beta.-pregnane-3.beta.,12.beta.,20.beta.-triol, the
Langendorff test on profused isolated heart shows an approximately 30 to
40% increase in the cardiac output for doses of 1 to 30 .mu.g/ml. In the
tests on isolated guinea-pig auricle, for a concentration of 10.sup.-5
g/liter, an approximately 150% increase in the concentration force is
found, relative to the control value. These results are confirmed by
varying the experimental conditions, after administration of propanolol,
proving the direct myocardial action of the compound and dispensing with
an adrenergic medication.
Comparaple resuls are obtained with
14.beta.-amino-21-nor-5.beta.-pregnane-3.beta.,20-triol.
The derivatives of the general formula (I) and their pharmaceutically
acceptable salts can be administered in the customary forms, the actvie
principle being diluted in a suitably chosen, pharmaceutically acceptable
carrier, for example in the form of tablets, gelatin capsules, coated
tablets, suppositories,injectable solutions or syrups.
By way of example, the tablets can be prepared by mixing the derivative of
the general formula (I) or one of its salts with one or more solid
diluents such as lactose, mannitol, starch, polyvinylpyrolidone, magnesium
stearate, talc and the like. If appropriate, the tablets can contain
several layers superimposed around a core, in accordance with the usual
techniques, inorder to ensure a sustained release or a delayed effect of
the active principle. The coating can consist, for example, of one or more
layers of polyvinyl acetate, carboxymethylcellulose or cellulose
acetophthalate.
The derivative according to the invention can also be administered in the
form of a syrup or a solution to be taken orally, which is obtained by
dissolving the derivative of the formula (I) or one of its
pharmaceutically acceptable salts in water or glycerol, for example, and,
if appropriate, incorporating a customary additive such as a sweetner or
an antioxidant.
Injectable solutions can be prepared in accordance with the well-known
techniques and consist, for example, of a solution containing a derivative
of the formula (I) or one of its pharmaceutically acceptable salts
dissolved in double-distilled water, an aqueous-alcoholic solution,
propylene glycol or the like, or a mixture of these solvents. If
appropriate, a suitable additive such as a preservative can be added.
The doses administered are determined by the doctor according to the chosen
method of administration, the severity of the complaint treated, the
duration of the treatment, and soon. For example, in the case of oral
administration to men, the doses can be between 0.005 and 5 mg/kg.
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Description |
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