New aminochromanol compounds

New aminochromanol compounds of the formula: ##STR1## in which X is cyano, nitro, trifluoromethyl, alkoxycarbonyl, carbamido, dialkylcarbamido, aminosulfonyl, dialkylaminosulfonyl, alkylsulfonyl, alkylsulfonylamino or acyl; PA0 CH.sub.2 -R is attached (in the 5 position of the pyrrolidinone nucleus) to an R- or S-configured carbon atom, and R is: PA1 either OR' or SR' in which R' is hydrogen, (C.sub.1 -C.sub.10)-alkyl, (C.sub.1 -C.sub.5 -alkyl)-carbonyl or ##STR2## and physiologically tolerable acid addition salts thereof, in the case where R contains a basic function. PA0 These compounds and their physiologically tolerable salts can be used in therapeutics for the activation of potassium channels, especially in the treatment of disorders associated with abnormal smooth muscle contraction and in the cardiovascular, bronchopulmonary, digestive, urinary and uterine fields.

The present invention provides aminochromanol compounds of the general 
formula I: 
##STR3## 
in which: 
X is selected from the group consisting of: a cyano radical, a nitro 
radical, a trifluoromethyl radical, alkoxycarbonyl radicals in which the 
alkoxy groups contain from 1 to 5 carbon atoms, in straight and branched 
chains, a carbamido radical, dialkylcarbamido radicals, an aminosulfonyl 
radical, dialkylaminosulfonyl radicals, alkylsulfonyl radicals and 
alkylsulfonylamino radicals in which the alkyl groups each contain from 1 
to 5 carbon atoms, and acyl radicals selected from: acetyl, propionyl, 
benzoyl and trifluoroacetyl radicals; 
CH2-R is attached (in the 5 position of the pyrrolidinone nucleus) to an R- 
or S- configured carbon atom, and 
R is selected from the group consisting of: 
(a) -OR' and SR' radicals in which R' is selected from the group consisting 
of: 
a hydrogen atom; 
alkyl and hydroxyalkyl radicals having up to 10 carbon atoms in straight 
and branched chains, and such chains interrupted by one or more oxygen 
atoms; 
alkylcarbonyl radicals in which the alkyl groups contain up to 5 carbon 
atoms in straight and branched chains; 
##STR4## 
radicals in which: n is an integer from 2 to 5, and R.sub.1 and R.sub.2, 
which are identical or different, are each selected from the group 
consisting of: 
a hydrogen atom, 
alkyl radicals having from 1 to 5 carbon atoms in straight and branched 
chains, and 
R.sub.1 and R.sub.2 together with the nitrogen atom to which they are 
bonded, form rings having 4 and 5 carbon atoms, and these rings containing 
another hetero atom selected from oxygen and sulfur atoms and a-N-R.sub.3 
group in which R.sub.3 is selected from the group consisting of: 
a hydrogen atom, 
alkyl radicals having from 1 to 5 carbon atoms in straight and branched 
chains, and 
an -A-Z radical in which 
A is selected from: a single bond, saturated C.sub.1 -C.sub.5 hydrocarbon 
chains, and such chains containing a double bond, and 
Z is selected from the group consisting of: 
a hydroxy radical, 
a benzhydryl radical, 
an unsubstituted phenyl radical, 
phenyl radicals mono and poly substituted by halogen atoms, 
trifluoromethyl, C.sub.1 -C.sub.5 alkoxy and methylene dioxy radicals, and 
penta and hexagonal heterocyclic radicals containing one and more oxygen, 
nitrogen and sulfur atoms, selected from pyridyl, thiazolyl, pyrimidinyl 
and pyrazinyl radicals, and such radicals mono and poly-substituted by 
halogen atoms, alkyl and alkoxy radicals each having from 1 to 5 carbon 
atoms and, 
##STR5## 
radicals in which R.sub.1 and R.sub.2 have the meanings given above. 
The nearest prior art to the present invention is illustrated especially 
by: 
J. M. EVANS et al., Med. Chem. 29 (II) 2194-2201 (1986); and 
the European patent Application published under no. 0076705 on 06.04.1983 
which relates to benzopyran compounds of which the leader product is 
CROMAKALIM corresponding to the formula: 
##STR6## 
which formula does not contain a substituent on the pyrrolidone nucleus. 
It has been found in investigation carried out by the applicants that the 
introduction of a substituent into the position .alpha. to the nitrogen 
atom of the pyrrolidone nucleus results in the compounds I of the present 
invention which are pure diastereoisomers which, compared with the racemic 
derivative, which is what CROMAKALIM is, have a particularly valuable 
advantage as regards therapeutic use. 
The compounds of the present invention, whose pharmacological profile is 
that of potassium agonist which can be used especially in the 
cardiovascular field, have, depending on the particular compound, a 
physiological activity comparable or superior to that of CROMAKALIM, with 
a duration of action much longer than that of the latter, hence their 
great advantage in therapeutic use. 
The present invention also relates to a process for the preparation of the 
compounds of the general formula I according to reaction scheme A: 
##STR7## 
characterised in that an equimolar amount of the chroman compound of the 
general formula II, in which X has the meaning defined above, is reacted 
with the R- or S-configured chiral pyrrolidone compound of the general 
formula III, in which R has the meaning defined above, in the form of the 
sodium or lithium salt. It is especially advantageous to carry out the 
reaction in an aprotic solvent at a temperature of from 20.degree. to 
50.degree. C. 
Examples of especially suitable aprotic solvents are dimethyl sulphoxide, 
hexamethylphosphorotriamide, dimethylformamide and dimethylacetamide. 
Pyrrolidone III must be converted beforehand into the sodium or lithium 
salt by means of sodium hydride or butyllithium, in the solvent chosen to 
carry out the reaction. 
The chroman compounds II can be prepared according to the technique of J. 
M. EVANS et al., J. Med. Chem. 26 (II) 1582-1589 (1983) and E.P. No. 
0076075. 
The R- or S-configured chiral pyrrolidone compounds III were prepared 
starting from natural R- or S-configured pyroglutamic acids, respectively, 
according to scheme B which follows: 
##STR8## 
described by S. SAIJO et al., Chem. Pharm. Bull. 28, 1449 (1980). 
R- or S-pyroglutaminol VI can be used as starting material in the 
preparation of the chiral pyrrolidones III 
either directly, in the case where R=OR', according to scheme C: 
##STR9## 
Z being a halogen atom, such as bromine or iodine, or a sulphate or 
arylsulphonate ion, and R' having the meaning defined above; the reaction 
generally being carried out in water or in an aprotic polar solvent in the 
presence of a strong base or a tertiary amine acting as acceptor of the 
acid formed; 
or after conversion by known methods into a halogenated, preferably 
chlorinated, compound of the formula: 
##STR10## 
which is reacted according to scheme D: 
##STR11## 
R representing either --OR' or SR' or 
##STR12## 
the reaction generally being effected according to known methods in an 
aprotic polar solvent, starting from an alkaline derivative of the 
compound R'OH or in the presence of an excess of amine 
##STR13## 
or of a tertiary base acting as acceptor of the hydracid formed. 
In the particular case of the compounds of the formula I in which R 
represents OR' and R' represents a hydrogen atom, that is to say, in order 
to prepare the compounds of the formula I': 
##STR14## 
it is preferable to carry out the reaction in accordance with scheme A 
given above, starting from an R- or S-configured chiral pyrrolidone of the 
formula 
##STR15## 
in which R" is a readily hydrolysable labile radical which can be prepared 
starting from compound VI and ethyl vinyl ether according to a technique 
described by S. SAIJO et al., Chem. Pharm. Bull. 28, 1449 (1980). 
The compounds of the general formula I are diastereoisomeric chiral 
substances. The method of synthesis according to scheme A always provides 
aminochromanols I in the trans-configuration by opening the epoxide 
function, and the use of S- or R-configured pyrrolidone III will give 
(after separation by column chromatography or by formation of salts and 
crystallisation of the latter where R contains a basic function) two pairs 
of pure diastereoisomers having the configuration 3S,4R,5'S and 3R,4S,5'S 
or 3S,4R,5'R and 3R,4S,5'R. 
Separation on a column is effected by flash chromatography, under nitrogen 
pressures of from 0.5 to 1 bar, with 35-70.mu. silica and solvent systems 
such as: CH.sub.2 Cl.sub.2 /methanol or CH.sub.2 Cl.sub.2 /ethyl acetate. 
Salt formation can be effected starting from compounds I in which R 
contains a basic function, and from mineral or organic acids and by 
recrystallisation of these salts in a suitable solvent. These salts are 
also included in the present invention. 
The compounds of the general formula I and their physiologically tolerable 
salts have valuable pharmacological and therapeutic properties, especially 
cell membrane potential modulating properties. 
These substances, which activate membrane potassium channels, increase an 
outward potassium flow and thus induce membrane hyperpolarisation. 
The mechanism of action of this new pharmacological class renders possible 
an original approach to the anomalies of cell membrane potential 
regulation and cell ion regulation, including modulation of the 
transmembrane and intracellular calcium movements, in addition to 
modulation of potassium fluxes. These anomalies are involved in numerous 
physiopathological processes associated especially with disorders in the 
regulation of the contraction of the various types of smooth muscle. 
Pharmacological tests carried out in vitro show that these products have a 
strong vascular relaxant activity compatible with an activation of 
membrane potassium channels. 
Tested in vivo on arterial hypertension models in the rat and the dog, 
these substances, when administered orally, have a strong antihypertensive 
activity which lasts very much longer than that of all currently described 
compounds having such a mechanism of action, especially CROMAKALIM, which 
is the nearest product of the prior art. 
Haemodynamic studies carried out on dogs demonstrate the strength and the 
long duration of their peripheral and coronary vasodilative effect. 
These properties enable the compounds of the invention to be used as 
medicaments, especially in the cardiovascular field: systemic and 
pulmonary arterial hypertension, myocardial ischaemia, peripheral vascular 
diseases and cardiac insufficiency, and, more generally, the treatment and 
prevention of disorders connected with arterial ageing and 
atherosclerosis. They can also be used in metabolic pathologies 
constituting a cardiovascular risk factor, such as: obesity, diabetes and 
dyslipidemias. 
In addition, the activity of these compounds on the various types of smooth 
muscle enables their therapeutic range to be extended to conditions 
associated with disorders in the regulation of smooth muscle contraction 
in the bronchopulmonary (obstructive bronchopneumopathy, asthma), 
digestive, urinary and uterine fields. 
Those therapeutic indications are not limiting inasmuch as the 
deterioration of cell membrane potential, whatever the cause, and tissue 
localisation result in cell disfunction, the origin of pathological 
phenomena, and may constitute a major therapeutic target of the products 
described. 
Thus, a number of conditions of tissue disorder, whether associated with 
ageing, ischaemia, inflammation or oedema (especially at the cerebral 
level), can be treated or prevented by the products of the present 
invention. 
The present invention also relates to pharmaceutical compositions 
containing as active ingredient a compound of the general formula I or one 
of its physiologically tolerable salts, mixed or associated with a 
suitable pharmaceutical excipient, such as, for example, distilled water, 
starch, talc, ethylcellulose or magnesium stearate. 
The pharmaceutical compositions so obtained are generally presented in 
dosage form and may contain from 0.05 to 50 mg of active ingredient. They 
may, for example, be in the form of tablets, dragees, soft gelatin 
capsules, suppositories, injectable or drinkable solutions as well as in 
the forms suitable for administration by aerosol and may, depending on the 
case, be administered orally, rectally or parenterally at a dose of from 
0.05 to 50 mg, once or twice per day.

The following Examples illustrate the invention. 
EXAMPLE 1: 
3R,4S- or 
3S,4R-trans-2,2-dimethyl-3-hydroxy-4-(2-oxo-5S-hydroxymethyl-1-pyrrolidiny 
l)-6-cyanochroman (A and B forms) 
##STR16## 
39 ml of a 1.6M butyllithium solution in hexane are added at 
15.degree.-20.degree. C. to a solution of 10.5 g of 
S(1-ethoxy-5-ethoxymethyl)-2-pyrrolidone in 20 ml of 
hexamethylphosphorotriamide. The whole is shaken for 30 minutes at 
20.degree. C. and then 14.1 g of 6-cyano-2,2-dimethyl-3,4-epoxychroman 
which melts (capillary) at 97.degree.-98.degree. C. are added. The whole 
is heated for 20 hours at 35.degree. C., cooled and 3.7 ml of acetic acid 
are added while shaking for 30 minutes at 5.degree.-10.degree. C. Dilution 
is effected with 200 ml of water and shaking is again carried out for 30 
minutes at 5.degree.-10.degree. C. An oily product separates out. The 
aqueous liquor is decanted and the oil is taken up again with 150 ml of 
water. A precipitate is then formed. CH.sub.2 Cl.sub.2 is added, the whole 
is shaken and the organic layer is decanted. After evaporation, 23 g of 
crude oil are obtained which are dissolved in 100 ml of methanol. The 
solution is shaken with 50 ml of 0.1N HCl for 2 hours to eliminate the 
protecting group. After evaporation of the solvent or flash column 
chromatography through 1 kg of silica using the system CH.sub.2 Cl.sub.2 
/methanol 95:5 as eluant, two pure fractions, R.sub.f =0.46 and 0.49, are 
isolated which correspond to the two pure diastereoisomers: 
form A: 4.6 g m.p. (cap)=152.degree.-153.degree. C., 
[.alpha.].sub.D.sup.20.degree.5 =-32.7.degree. (c=1 EtOH). 
form B: 3.8 g m.p. (cap)=156.degree.-158.degree. C., 
[.alpha.].sub.D.sup.20.degree.5 =-62.9.degree. (c=1 EtOH). 
The S-(1-ethoxy-5-ethoxymethyl)-2-pyrrolidone used as starting material 
(oil) [.alpha.].sub.D.sup.20.degree.5 =+21.8.degree. (c=1 EtOH) was 
prepared, with a yield of 96%, by adding ethyl vinyl ether in CHCl.sub.3, 
in the presence of CF.sub.3 COOH, to 5S-hydroxymethyl-2-pyrrolidone (oil) 
[.alpha.].sub.D.sup.21 =+33.degree.5 (c=3 EtOH). 
EXAMPLE 2: 
3S,4R- or 
3R,4S-trans-2,2-dimethyl-3-hydroxy-4-(2-oxo-5S-methoxymethyl-1-pyrrolidiny 
l)-6-cyanochroman (A and B forms) 
##STR17## 
The forms: 
A, [.alpha.].sub.D.sup.21 =-69.6.degree. (c=1 EtOH), M.P. 
(cap)=186.degree.-189.degree. C. and 
B, [.alpha.].sub.D.sup.21 =+1.22.degree. (c=1 EtOH), M.P. 
(cap)=142.degree.-145.degree. C. 
were prepared in accordance with the method described in Example 1, 
starting from 5S-methoxymethyl-2-pyrrolidone (oil), which was itself 
prepared starting from 5S-hydroxymethyl-2-pyrrolidone and dimethyl 
sulphate in the presence of sodium hydroxide, with a yield of 60%. 
EXAMPLE 3: 
3R,4S- or 
3S,4R-trans-2,2-dimethyl-3-hydroxy-4-(2-oxo-5S-dimethylaminomethyl-1-pyrro 
lidinyl)-6-cyanochroman, (A and B forms): 
##STR18## 
The forms: 
A, m.p. (cap)=153.degree.-156.degree. C., [.alpha.].sub.D.sup.20.degree.5 
=-39.degree. (c=1 DMSO) 
B oxalate, m.p. (cap)=194.degree.-197.degree. C., 
[.alpha.].sub.D.sup.20.degree.5 =-41.1.degree. (c=1 EtOH). 
were prepared in accordance with the method described in Example 1 starting 
from 5S-dimethylaminomethyl-2-pyrrolidone (oil) of 96% optical purity 
(HPLC), which was itself prepared by heating 5S-chloromethyl-2-pyrrolidone 
(oil) of 94% optical purity (HPLC, chiral column) at 100.degree. C. with 
an excess of dimethylamine in ethanol. 
EXAMPLES 4-30: 
By proceeding as in Example 1, and using suitable starting materials, the 
products forming the subject of the following Examples (A and B forms) 
were prepared: 
__________________________________________________________________________ 
##STR19## 
n.degree. Ex 
X R 
__________________________________________________________________________ 
4 CN OCOCH.sub.3 
5 CN O(CH.sub.2).sub.5CH.sub.3 
6 CN OCH.sub.2 CH.sub.2OCH.sub.3 
7 CN O(CH.sub.2).sub.2N(CH.sub.3).sub.2 
8 CN O(CH.sub.2).sub.2N(C.sub.2 H.sub.5).sub.2 
9 CN N(C.sub.2 H.sub.5).sub.2 
10 CN 
##STR20## 
11 CN 
##STR21## 
12 CN 
##STR22## 
13 CN 
##STR23## 
14 CN 
##STR24## 
15 CN 
##STR25## 
16 CN 
##STR26## 
17 CN 
##STR27## 
18 CN 
##STR28## 
19 CN 
##STR29## 
20 CN 
##STR30## 
21 CN 
##STR31## 
22 CN OCH.sub.2CH.sub.2OH 
23 NO.sub.2 OH 
24 
##STR32## OH 
25 CN SH 
26 COCH.sub.3 OH 
27 SO.sub.2 CH.sub.3 
OH 
28 
##STR33## OH 
29 CF.sub.3 OH 
30 NHO.sub.2 SCH.sub.3 
OH 
__________________________________________________________________________ 
EXAMPLE 20: 
Pharmacological study in vitro in the cardiovascular field: 
Male Wistar rats (325-375 g) are anaesthetised i.p. using sodium 
pentobarbital (30 mg/kg). The thoracic aorta and the mesenteric portal 
vein are removed. The aorta is dissected into rings 3 mm long and the 
endothelium is removed mechanically. 
1 cm of the portal vein is cut out and attached at its ends. 
The organs are placed in a 20 ml thermostatically controlled vessel 
containing a physiological solution composed of (mM): NaCl 112; KCl 5; 
KH.sub.2 PO.sub.4 1; MgSO.sub.4 1.2; CaCl.sub.2 2.5; NaHCO.sub.3 25; 
glucose 11.5; EDTA 0.1; pH: 7.4; 37.degree. C.; 95% O.sub.2 +5% CO.sub.2. 
The initial force applied is 2 g in the case of the aorta and 0.5 g in the 
case of the portal vein. The variations in force are measured by a STATHAM 
sensor connected to a transducer amplifier (GOULD) and are monitored 
continuously on a GOULD 2400 graphic recorder. 
The experimental protocols are as follows: After a stabilisation period of 
90 minutes, the aortic rings are subjected to various tests: 
potassium depolarisation: 
The preparations are exposed to a 30 mM or 80 mM KCl (and 87 and 37 mM 
NaCl, respectively) hyperpotassium medium; after 30 minutes' stabilisation 
of contraction, cumulative concentrations of the product to be tested are 
added every 15 minutes. The relaxation values obtained allow the IC.sub.50 
s to be calculated. 
reactivity to 4-aminopyridine (4 AP) 
The product to be tested, at a given concentration, or its solvent, is 
incubated in the normal physiological solution 15 minutes before the 
addition of the 4 AP (5 mM). 
The maximum amplitudes of the responses to the 4 AP in the presence of the 
product or the solvent are compared. 
The portal vein exhibits a stable spontaneous rhythmic activity in 60 
minutes. Cumulative concentrations of the product to be tested are added 
to the medium every 15 minutes; the frequency and amplitude variations of 
the peaks are recorded. 
The products are used in a form dissolved in water or a suitable solvent. 
The concentrations expressed refer to the final concentrations in terms of 
base in the isolated organ baths. 
The results obtained are grouped in the following Table: 
__________________________________________________________________________ 
AORTA OF THE RAT 
% inhibition of the 
PORTAL VEIN 
response to 4AP accord- 
Suppression 
Products IC.sub.50 (M) 
KCl ing to the concentration 
of rhythmic 
tested 30 mM 80 mM 
of product (M) 
activity (M) 
__________________________________________________________________________ 
CROMAKALIM 
4.2 .times. 10.sup.-7 
&gt;10.sup.-4 
13% (10.sup.-7) 
3 .times. 10.sup.-7 
74% (10.sup.-5) 
Ex. 1 Form A 
7.7 .times. 10.sup.-6 
&gt;10.sup.-4 
35% (10.sup.-5) 
10.sup.-5 
Ex. 1 Form B 
3.4 .times. 10.sup.-7 
&gt;10.sup.-4 
18% (3 .times. 10.sup.-6) 
3 .times. 10.sup.-7 
77% (10.sup.-5) 
10.sup.-5 
Ex. 2 Form A 
2.8 .times. 10.sup.-7 
&gt;10.sup.-4 
__________________________________________________________________________ 
Examination of this Table shows that: 
The products tested have a strong vascular relaxant activity in a medium 
depolarised by a low potassium concentration (30 mM), the activity 
disappearing at a high potassium concentration (80 mM). 
The vascular contractions induced by 4-aminopyridine (antagonist of 
potassium channels) are strongly inhibited by these compounds. 
The spontaneous rhythmic activity of the portal vein, which is sensitive to 
the variation in membrane potential, is greatly impaired by the products 
described. 
These results, taken as a whole, are compatible with a membrane 
hyperpolarising mechanism of action by activation of potassium channels. 
The strength of activity of the product of Example 1, form B, is comparable 
in these tests to that of the strongest reference product known: 
CROMAKALIM. 
EXAMPLE 21: 
Pharmacological study in vivo in the cardiovascular field 
A- The study comprises the following tests: 
1- STUDY ON THE SPONTANEOUSLY HYPERTENSIVE RAT (SHR) 
1-1- METHODOLOGY 
The study is carried out on SHR male rats (Charles River) weighing from 260 
g to 330 g and aged from 18 to 20 weeks. A polyethylene catheter is 
positioned at the level of the abdominal aorta and tunnelised at the level 
of the neck under anaesthesia (ketamine hydrochloride 150 mg/kg 
intraperitoneally). The animals, placed in movement-restraining cages, are 
tested in the conscious state at least 48 hours after intervention. The 
arterial pressure, measured by a STATHAM P23 pressure sensor connected to 
the abdominal catheter, is registered on a GOULD 2400 recorder. The 
products are administered orally in dissolved form (water or suitable 
solvent) at a dose of 2.5 mg/kg. The doses administered are expressed in 
mg/kg of base. 
1-2- RESULTS 
The results obtained with a certain number of representative products of 
the invention and a reference product, CROMAKALIM, are grouped in the 
following Table. The variations in systolic and diastolic arterial 
pressure (PAS and PAD) presented at the most significant times after 
treatment are expressed as percentage variation with respect to the 
control values. 
__________________________________________________________________________ 
CONTROL VARIATIONS (%) AS A FUNCTION OF TIME 
Products DOSE VALUES AFTER TREATMENT 
tested mg/kg mmHg 30 min 
1 H 3 H 6 H 
__________________________________________________________________________ 
CROMAKALIM 
0.3 6 PAS 202 .+-. 9 
-29 .+-. 2 
-21 .+-. 3 
-5 .+-. 4 
-1 .+-. 2 
PAD 129 .+-. 6 
-34 .+-. 2 
-26 .+-. 3 
-7 .+-. 5 
-3 .+-. 1 
CROMAKALIM 
1.0 6 PAS 211 .+-. 10 
-34 .+-. 5 
-23 .+-. 4 
-19 .+-. 3 
-15 .+-. 2 
PAD 136 .+-. 8 
-44 .+-. 4 
-33 .+-. 3 
-25 .+-. 4 
-20 .+-. 2 
Example 1 
0.3 4 PAS 219 .+-. 7 
-27 .+-. 5 
-27 .+-. 4 
-25 .+-. 3 
- 29 .+-. 3 
form B PAD 146 .+-. 5 
-34 .+-. 6 
-36 .+-. 4 
-35 .+-. 4 
-40 .+-. 4 
Example 1 
1.0 4 PAS 213 .+-. 5 
-42 .+-. 2 
-44 .+-. 1 
-40 .+-. 2 
-36 .+-. 3 
form B PAD 135 .+-. 5 
-48 .+-. 5 
-54 .+-. 2 
-46 .+-. 6 
-46 .+-. 4 
Example 2 
1.0 5 PAS 192 .+-. 4 
-11 .+-. 2 
-16 .+-. 3 
-12 .+-. 3 
-9 .+-. 2 
form A PAD 118 .+-. 3 
-17 .+-. 3 
-21 .+-. 4 
-19 .+-. 3 
-14 .+-. 2 
Example 2 
3.0 6 PAS 203 .+-. 3 
-24 .+-. 1 
-26 .+-. 2 
-25 .+-. 3 
-21 .+-. 3 
form A PAD 130 .+-. 3 
-35 .+-. 3 
-36 .+-. 3 
-31 .+-. 3 
-27 .+-. 3 
__________________________________________________________________________ 
1-3- CONCLUSION OF THE IN VIVO STUDY ON SHR 
The products of the invention have a remarkable antihypertensive activity 
in SHR rats after oral administration of low doses. The duration of action 
of the products described is considerably prolonged compared with that of 
the best reference product known, CROMAKALIM, with a comparable maximum 
activity, and constitutes an important therapeutic advantage. 
2- STUDY ON THE CONSCIOUS RENALLY HYPERTENSIVE DOG 
2-1- METHODOLOGY 
Mongrel dogs weighing from 20 to 25 kg are used. A silastic catheter 
positioned under anaesthesia (sodium pentobarbital 30 mg/kg i.v.) at the 
level of the abdominal aorta and left over a prolonged period permits the 
later measurement of the arterial pressure in the conscious animals. 
Arterial hypertension is induced by a second intervention under 
anaesthesia consisting in a constriction of the left renal artery using a 
clip, which reduces its rate of flow by approximately 70%, the left kidney 
is enveloped in a latex capsule and the contralateral kidney is left in 
place. 
The systolic and diastolic arterial pressures (PAS and PAD) are measured 
using a STATHAM P23 pressure sensor connected to the silastic catheter and 
linked to a GOULD pressure amplifier. The products are tested on the 
animals, which have become hypertensive, in the conscious state, at least 
one week after the second intervention. The arterial pressure is monitored 
continuously on an ES1000 GOULD recorder until 7 hours have elapsed after 
the treatment and then until 24 hours have elapsed. 
The products to be tested are administered via the digestive system, after 
gastric intubation, in a form dissolved in water or a suitable solvent. 
The doses administered are expressed in mg of base with respect to body 
weight. 
2-2- RESULTS 
The representative products of the invention were compared with the 
reference product (CROMAKALIM). The variations in the systolic and 
diastolic arterial pressures (PAS and PAD), presented at the most 
significant times after treatment, are expressed as percentage variation 
with respect to the control values. 
__________________________________________________________________________ 
CONTROL 
VARIATIONS (%) AS A FUNCTION OF TIME 
Products DOSE 
VALUES AFTER TREATMENT 
tested mg/kg 
mmHg 30 min 
1 H 3 H 7 H 24 H 
__________________________________________________________________________ 
CROMAKALIM 
0.1 PAS 189 
-50 -26 -9 +2 +9 
PAD 93 -46 -23 -9 -5 +18 
Example 1 
0.1 PAS 199 
0 +2 -55 -76 -24 
form B PAD 99 0 +5 -50 -68 -27 
Example 2 
0.1 PAS 181 
-2 -12 -28 -41 -2 
form A PAD 93 -14 -20 -32 -44 0 
__________________________________________________________________________ 
2-3- CONCLUSION OF THE IN VIVO STUDY IN THE RENALLY HYPERTENSIVE DOG 
Strong antihypertensive activity and long duration of action of these 
products is observed in the renally hypertensive dog. The superiority of 
the product of Example 1, form B, in terms of strength and duration of 
action in comparison with CROMAKALIM is to be especially underlined. 
3- HAEMODYNAMIC STUDY IN THE ANAESTHETISED DOG 
3-1- METHODOLOGY 
A complete haemodynamic study was carried out on mongrel dogs weighing from 
25 to 30 kg, which were anaesthetised with sodium pentobarbital 30 mg/kg 
i.v., intubated and ventilated and subjected to a thoracotomy at the 5th 
left intercostal space. The measurement of the mean coronary and cardiac 
outputs is carried out using electromagnetic rings positioned at the level 
of the ascending aorta and the circumflex branch of the left coronary 
artery, respectively, and connected to GOULD SP 2202 electromagnetic flow 
meters. The aortic pressure is measured by a MILLAR probe introduced via 
the femoral artery. 
The total peripheral vascular resistance values (TPR) and the mean coronary 
vascular resistance values (CVRM) are calculated by the ratio between the 
mean aortic pressure and the mean cardiac output and the mean coronary 
output, respectively. The products tested were injected via the femoral 
vein in a form dissolved in water or a suitable solvent. 
3-2- RESULTS 
The results obtained with the tested products of the invention are compared 
with the reference product CROMAKALIM. 
The evolution of the vascular resistances, expressed as percentage 
variation with respect to the control values, is presented as a function 
of time in the following Table. 
__________________________________________________________________________ 
VARIATION (%) AS A FUNCTION OF TIME 
Products DOSE AFTER TREATMENT 
tested .mu.g/kg 
AMETER 
1 min 10 min 30 min 
__________________________________________________________________________ 
CROMAKALIM 
10 CVRM -69.0 -38.1 -27.4 
TPR -26.8 -15.5 -7.8 
Example 1 
10 CVRM -69.4 -62.0 -43.7 
form B TPR -45.9 -35.1 -35.1 
Example 1 
300 CVRM -81.5 -50.3 -34.9 
form A TPR -41.9 -17.2 -12.9 
Example 2 
30 CVRM -28.9 -20.2 -22.1 
form A TPR -9.8 -11.8 -11.8 
Example 2 
100 CVRM -54.7 -56.1 -50.5 
form A TPR -15.8 -14.7 -12.6 
Example 3 
3000 
CVRM +2.5 -38.5 -49.0 
form A TPR +1.7 -6.8 -8.5 
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3-3- CONCLUSION OF THE HAEMODYNAMIC STUDY ON THE DOG 
Administered intravenously at a low dose, the compounds of the invention 
have a strong peripheral and coronary vasodilative activity which is 
better maintained than that of CROMAKALIM. 
B- In general, all of the in vivo tests carried out permit the conclusion 
that the compounds of the present invention have an activity which is 
comparable or superior to that of the best reference product known 
(CROMAKALIM) while at the same time having a duration of action very much 
greater than that of the latter, which constitutes a major advantage for 
therapeutic use. 
EXAMPLE 22: 
Pharmacological study in the bronchopulmonary field: 
The bronchodilating activity has been studied in the guinea pig by the 
method of H. KONZETT and R. ROSSLER, Arch. Exp. Path. U. Pharm. 195, 71 
(1940). 
It has been observed that the compounds of the present invention injected 
intravenously at doses varying, according according to the compounds, from 
0.3 to 1 mg/kg inhibit notably the bronchospasm provoked by the 
intravenous administration either of histamine or serotonin or 
acetylcholine. 
For example, the bronchospasm produced in the guinea pig by a histamine 
aerosol et 4% is inhibited of 96% by the compound of Example 1 B form, at 
the dose of 0.30 mg/kg i.v., and of 100% by the compound of Example 24 B 
form, at the dose of 0.35 mg/kg i.v. 
When submitted to the test of A. K. ARMITAGE, Brit. J. Pharmacol. 17, 196 
(1961), the tested compounds, administered by oral route or aerosol at 
doses between 0.5 to 4 mg/kg, depending on the compounds, inhibit of from 
11 to 68% the effect produced in the guinea pig by a histamine aerosol at 
4%. 
EXAMPLE 23: 
Pharmaceutical preparation: 
Soft gelatin capsules containing 1 mg of active ingredient 
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3R, 4S- or 3S, 4R-trans-2,2-dimethyl-3-hydroxy-4- 
1 mg 
(2-oxo-5S-hydroxymethyl-1-pyrrolidinyl)-6-cyanochroman 
corn starch 15 mg 
lactose 25 mg 
talc 5 mg 
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