U.S. patent application number 09/746041 was filed with the patent office on 2001-08-16 for benflumetol derivatives, intermediates thereof and their use against parasitical protozoa and trematodes.
Invention is credited to Allmendinger, Thomas, Wernsdorfer, Walther Helmut.
Application Number | 20010014699 09/746041 |
Document ID | / |
Family ID | 4208448 |
Filed Date | 2001-08-16 |
United States Patent
Application |
20010014699 |
Kind Code |
A1 |
Allmendinger, Thomas ; et
al. |
August 16, 2001 |
Benflumetol derivatives, intermediates thereof and their use
against parasitical protozoa and trematodes
Abstract
The invention relates to a compound of formula (1), 1 wherein R
is an alkyl unsubstituted by one or more polar substituents or an
alkenyl unsubstituted or substituted by one or more polar
substituents, and X is aryl, or salts thereof. The compounds are
effective e.g. against protozoa and trematodes.
Inventors: |
Allmendinger, Thomas;
(Lorrach, DE) ; Wernsdorfer, Walther Helmut;
(Wien, AU) |
Correspondence
Address: |
THOMAS HOXIE
NOVARTIS CORPORATION
PATENT AND TRADEMARK DEPT
564 MORRIS AVENUE
SUMMIT
NJ
079011027
|
Family ID: |
4208448 |
Appl. No.: |
09/746041 |
Filed: |
December 22, 2000 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
09746041 |
Dec 22, 2000 |
|
|
|
PCT/EP99/04355 |
Jun 23, 1999 |
|
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Current U.S.
Class: |
514/653 ;
564/237 |
Current CPC
Class: |
A61P 33/02 20180101;
A61P 33/06 20180101; C07C 2603/18 20170501; A61P 33/10 20180101;
C07C 217/08 20130101; C07C 215/38 20130101 |
Class at
Publication: |
514/653 ;
564/237 |
International
Class: |
A61K 031/135; C07C
277/00; C07C 279/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 25, 1998 |
CH |
1351/98 |
Claims
What is claimed is:
1. A compound of formula I 11wherein R is an alkyl unsubstituted or
substituted by one or more polar substituents or an alkenyl
unsubstituted or substituted by one or more polar substituents, and
X is unsubstituted or substituted aryl, or a salt thereof.
2. A compound of claim 1 wherein R is unsubstituted or mono-, di-,
or trisubstituted C.sub.1-C.sub.8alkyl, the substituents being
selected from amino, hydroxy and guanidino and not bonded in
position 1 of the alkyl radical, and X is halogenphenyl, or a salt
thereof.
3. A compound of formula I, wherein R is C.sub.1-C.sub.8alkyl, in
particular methyl, n-butyl, sec-butyl, n-pentyl or n-octyl, and X
is 4-chlorophenyl, or a salt thereof.
4. The compound of formula I wherein R is n-butyl and X is
4-chlorophenyl, or a salt thereof.
5. A combination of a compound of formula I, or a salt thereof,
according to claim 1 with one or more other pharmaceutical active
substances, or in each case a salt thereof if at least one
salt-forming group is present in each case.
6. A combination of a compound of formula I, or a salt thereof,
according to claim 2 with one or more other pharmaceutical active
substances, or in each case a salt thereof if at least one
salt-forming group is present in each case.
7. A combination of a compound of formula I, or a salt thereof,
according to claim 3 with one or more other pharmaceutical active
substances, or in each case a salt thereof if at least one
salt-forming group is present in each case.
8. A combination of a compound of formula I, or a salt thereof,
according to claim 4 with one or more other pharmaceutical active
substances, or in each case a salt thereof if at least one
salt-forming group is present in each case.
9. A product comprising (a) an active substance of formula I, or a
salt thereof, according to claim 1, and (b) as a further component
one or more further active substances, or a salt thereof in each
case if at least one salt-forming group is present, in the presence
or absence of one or more pharmaceutically acceptable carriers as a
combination product for administration simultaneously or at
different times to a warm-blooded animal.
10. A product comprising (a) an active substance of formula I, or a
salt thereof, according to claim 2, and (b) as a further component
one or more further active substances, or a salt thereof in each
case if at least one salt-forming group is present, in the presence
or absence of one or more pharmaceutically acceptable carriers as a
combination product for administration simultaneously or at
different times to a warm-blooded animal.
11. A product comprising (a) an active substance of formula I, or a
salt thereof, according to claim 3, and (b) as a further component
one or more further active substances, or a salt thereof in each
case if at least one salt-forming group is present, in the presence
or absence of one or more pharmaceutically acceptable carriers as a
combination product for administration simultaneously or at
different times to a warm-blooded animal.
12. A product comprising (a) an active substance of formula I, or a
salt thereof, according to claim 4, and (b) as a further component
one or more further active substances, or a salt thereof in each
case if at least one salt-forming group is present, in the presence
or absence of one or more pharmaceutically acceptable carriers as a
combination product for administration simultaneously or at
different times to a warm-blooded animal.
13. A pharmaceutical composition comprising a compound of formula I
or a pharmaceutically acceptable salt thereof according to claim 1,
together with at least one pharmaceutically acceptable carrier.
14. A pharmaceutical composition comprising a compound of formula I
or a pharmaceutically acceptable salt thereof according to claim 2,
together with at least one pharmaceutically acceptable carrier.
15. A pharmaceutical composition comprising a compound of formula I
or a pharmaceutically acceptable salt thereof according to claim 3,
together with at least one pharmaceutically acceptable carrier.
16. A pharmaceutical composition comprising a compound of formula I
or a pharmaceutically acceptable salt thereof according to claim 4,
together with at least one pharmaceutically acceptable carrier.
17. A method for the therapeutic or prophylactic treatment of a
protozoan or a trematode disease in a subject in need of such
treatment comprising administering to the subject a therapeutically
effective amount of a compound according to claim 1.
18. A method for the preparation of a compound of formula I
according to claim 1, or a salt thereof, comprising a) condensing a
compound of formula II 12wherein R is as defined for a compound of
formula I, with an aldehyde of formula III, 13wherein X is as
defined for compounds of formula I, or b) adding to an oxiran of
formula IV 14wherein X is as defined for compounds of formula I, an
amine of formula V, 15wherein R is as defined for a compound of
formula I, wherein any free functional groups which are present in
one of the educts of formula II in method a) or in one of the
educts of formula IV and/or V in method b) and which are not
supposed to take part in the reaction are present in protected form
if necessary, and any protecting groups present are removed; and,
if so desired, reacting any free compound of formula I resulting
from the procedures described under a) or b) to form its salt or
any resulting salt of a compound of formula I to form either a free
compound of formula I or another salt of a compound of formula I,
or separating into its isomers a compound of formula I that is
present as an isomeric mixture.
Description
[0001] This is a continuation of International Application No.
PCT/EP99/04355, filed Jun. 23, 1999, the contents of which are
incorporated herein by reference.
SUMMARY OF THE INVENTION
[0002] The invention relates to N-substituted
2-amino-1-[2,7-dichloro-9-(a- ryl)-9H-fluoren-4-yl] -ethanols,
methods for the preparation of these compounds, new intermediate
products, pharmaceutical preparations and fixed or variable
combinations comprising these compounds, the use of these compounds
(alone or in fixed or free combination) and/or combinations for the
therapeutic or prophylactic treatment of diseases or for the
preparation of pharmaceutical preparations and methods for the
therapeutic or prophylactic treatment of warm-blooded animals
comprising the administration of these compounds or
combinations.
BACKGROUND TO THE INVENTION
[0003] Parasitic diseases, in particular those caused by protozoa
(such as malaria, pathogens: plasmodia), or by trematodes (such as
schistosomiasis, for example urinary schistosomiasis, caused by
schistosomes, as Schistosoma haematobium), constitute a substantial
proportion of the diseases, especially in developing countries.
Malaria, transmitted by the Anopheles mosquito and caused by
protozoa of the Plasmodium genus, is a disease which occurs in
about 100 million people each year, of whom around one million die.
A distinction is drawn between Malaria tropica (caused by
Plasmodium falciparum), Malaria tertiana (caused by Plasmodium
vivax or Plasmodium ovale) and Malaria quartana (caused by
Plasmodium malariae). Malaria tropica is the most severe form of
the disease.
[0004] Benflumetol (also lumefantrine), a compound of formula 2
[0005] is a compound which, in combination with artemether (see EP
0 500 823)--a sesquiterpene lactone derivative of the naturally
occurring substance artemisinin with the name [3R-(3.alpha.,
5.alpha..beta., 6.beta., 8.alpha..beta., 9.alpha., 10.alpha.,
12.beta.,-12aR)]-decahydro--
10-methoxy-3,6,9-trimethyl-3,12-epoxy-12H-pyrano[4,3-j]-1,2-benzodioxepin,
is in the review stage for approval worldwide as a treatment for
malaria.
[0006] Because of phenomena such as the development of resistance,
it remains an urgent necessity to find new compounds which show
particularly good efficacy against malaria and minimal
toxicity.
[0007] The different half-lives of the substances which are active
against malaria also mean that further compounds should be made
available which show a pharmacokinetic behaviour distinct from the
antimalarial substances already established. Chloroquine, for
example, has a very long half-life, artemether a relatively short
half-life (2 hours in plasma), and benflumetol for example has a
plasma half-life of 4-6 days in patients.
[0008] The solubility of benflumetol is also not very good, and
when it is taken for example with foods having a high fat content
the absorption can be up to 16 times higher than it is in the
absence of such fatty foods, so that dosing cannot be optimally
controlled.
[0009] Surprisingly, a new class of compounds has now been found
which have a number of beneficial properties, meet one or more of
the above requirements in particular, and facilitate for example
the treatment of severe cases of malaria or a corresponding
prophylaxis, or in the broader sense of schistosomiasis, the
prevention or treatment of potentially multiresistant malaria, and
new pharmaceutical formulations, and thus an improved
pharmacokinetics, but in particular show especially good efficacy
against plasmodia.
DETAILED DESCRIPTION OF THE INVENTION
[0010] The invention relates to a compound of formula I, 3
[0011] wherein R is an alkyl unsubstituted or substituted by one or
more polar substituents or an alkenyl unsubstituted or substituted
by one or more polar substituents, and X is aryl, or a salt
thereof.
[0012] The general terms used hereinbefore and hereinafter
preferably have within the context of this disclosure the following
meanings, unless otherwise indicated:
[0013] The prefix "lower" denotes a radical having up to and
including a maximum of 7, especially up to and including a maximum
of 4 carbon atoms, the radicals in question being either linear or
branched with single or multiple branching.
[0014] Where the plural form is used for compounds, salts, and the
like, this is taken to mean also a single compound, salt, or the
like.
[0015] Any asymmetric carbon atoms may be present in the (R)-, (S)-
or (R,S) configuration, preferably in the (R)- or (S)
configuration. Substituents at a double bond or a ring may be
present in cis- (.dbd.Z-) or trans (.dbd.E-) form. The compounds
may thus be present as mixtures of isomers or as pure isomers,
preferably as enantiomer-pure diastereomers. Especially preferred
are in each case the E or Z form of a compound of formula I, which
with regard to the C--OH in formula I are present as an
enantiomeric mixture (in particular a racemate). The
enantiomer-pure E and Z forms are also important.
[0016] Alkyl may be a singly or multiply branched or straight-chain
substituent; alkyl preferably has up to 10 carbon atoms and
especially up to 8 carbon atoms, and is in particular
C.sub.1-C.sub.5alkyl, for example n-pentyl, n-butyl, sec-butyl,
tert-butyl, n-propyl, isopropyl, ethyl or methyl, or octyl, for
example n-octyl. Methyl, n-pentyl, n-butyl and sec-butyl are
especially preferred.
[0017] Alkyl with up to 8 carbon atoms which is substituted by a
polar radical, preferably n-pentyl, n-butyl or sec-butyl, is
especially substituted by one or more, especially up to three polar
substituents selected from the group consisting of amino, N-lower
alkylamino, N,N-di-lower alkylamino, hydroxy, hydroxy-lower alkoxy,
such as 2-hydroxyethoxy, hydroxy-lower alkoxy-lower alkoxy, such as
2-(2-hydroxyethoxy)ethoxy, carboxy, amidino and guanidino,
especially amino, hydroxy and guanidino. If otherwise unstable
compounds are present, such substituents are preferably not bonded
on the carbon-1 atom (which bonds R to the nitrogen in formula
1).
[0018] Alkenyl is preferably alkenyl with up to 8 carbon atoms and
is in particular lower alkenyl with 3 to 7, especially 3 or 4
carbon atoms, wherein the carbon atom binding the nitrogen in
formula I may not form a double bond (double bond only in the 2
position or higher, because otherwise the compound would be
unstable).
[0019] Alkenyl which is substituted by a polar radical and has up
to 8 carbon atoms, in particular C.sub.3-C.sub.7lower alkenyl, is
substituted especially by one or more, in particular up to three
polar substituents selected from the group consisting of amino,
N-lower alkylamino, N,N-di-lower alkylamino, hydroxy, carboxy,
amidino and guanidino, especially amino, hydroxy and guanidino. In
the case of hydroxy, amino, lower alkylamino and guanidino, this
substituent may not be bonded to a carbon atom which is linked to
the radical of the molecule via a double bond. If otherwise
unstable compounds are present, such substituents are moreover
preferably not bonded on the carbon-1 atom (the atom which bonds R
to the nitrogen in formula 1) (this is often the case especially
with hydroxy, amino, and guanidino).
[0020] Halogen is above all fluorine, chlorine, bromine, or iodine,
especially fluorine, chlorine, or bromine.
[0021] Aryl is in particular C.sub.6 to C.sub.14aryl, especially
fluorenyl, napthyl or in particular phenyl, the said radicals being
unsubstituted or substituted by one or more substituents selected
from the group comprising halogen, especially chlorine; hydroxy;
substituted hydroxy, in particular lower alkanoyloxy, phenyl-lower
alkoxy or lower alkoxy; amino; monosubstituted or disubstituted
amino, in particular amino substituted by lower alkanoyl,
phenyl-lower alkyl or lower alkyl monosubstituted or disubstituted
amino; lower alkyl; substituted lower alkyl, such as phenyl-lower
alkyl, halogen-lower alkyl, cyano-lower alkyl, carbamoyl-lower
alkyl, carboxy-lower alkyl, lower alkoxycarbonyl-lower alkyl or
phenyl-lower alkoxycarbonyl-lower alkyl substituted lower alkyl;
phenyl; naphthyl; carboxy; esterified carboxy, for example lower
alkoxycarbonyl, phenyl-lower alkoxycarbonyl or phenoxycarbonyl,
amidino, cyano, nitro and sulfo. Aryl is in particular
4-chlorophenyl.
[0022] Salts are primarily the pharmaceutically acceptable salts of
compounds of formula I.
[0023] Such salts are formed, for example, as acid addition salts,
preferably with organic or inorganic acids, from compounds of
formula I with a basic nitrogen atom. Suitable inorganic acids are,
for example, halogen acids, such as hydrochloric acid; sulfuric
acid; or phosphoric acid. Suitable organic acids are for example
carboxylic, phosphonic, sulfonic or sulfamic acids, for example
acetic acid, glycolic acid, lactic acid, fumaric acid, succinic
acid, adipic acid, malic acid, tartaric acid, citric acid, glucaric
acid, galactaric acid, amino acids, such as glutamic acid, aspartic
acid, maleic acid, hydroxymaleic acid, benzoic acid, phenylacetic
acid, methane- or ethanesulfonic acid, 2-hydroxyethanesulfonic
acid, ethane-1,2-disulfonic acid, benzenesulfonic acid,
2-naphthalenesulfonic acid, 1 ,5-naphthalenedisulfonic acid, 2-, 3-
or 4-methylbenzenesulfonic acid, N-cyclohexylsulfamic acid,
N-methyl, N-ethyl, or N-propyl-sulfamic acid, or other organic
protonic acids, such as ascorbic acid.
[0024] In the presence of negatively charged radicals, such as
carboxy, salts may also be formed with bases, e.g. metal or
ammonium salts, such as alkali metal or alkaline earth metal salts,
for example sodium, potassium, magnesium or calcium salts, or
ammonium salts with ammonia or suitable organic amines, such as
tertiary monoamines, for example triethylamine or
tri(2-hydroxyethyl)amine, or heterocyclic bases, for example
N-ethylpiperidine or N,N'-dimethylpiperazine.
[0025] In the presence of a basic group and an acid group in the
same molecule, a compound of formula 1 may also form internal
salts.
[0026] For isolation or purification purposes it is also possible
to use pharmaceutically unacceptable salts, for example picrates or
perchlorates. Only the pharmaceutically acceptable salts or free
compounds (if the occasion arises, in the form of pharmaceutical
preparations) attain therapeutic use, and these are therefore
preferred.
[0027] In view of the close relationship between the novel
compounds in free form and in the form of their salts, including
those salts that can be used as intermediates, for example in the
purification or identification of the novel compounds, any
reference hereinbefore and hereinafter to the free compounds is to
be understood as referring also to the corresponding salts, as
appropriate and expedient.
[0028] Compounds of formula I show beneficial pharmacological
properties. In particular they show a high degree of efficacy
against protozoa, such as plasmodia, and also against trematodes,
such as schistosomes.
[0029] The efficacy against plasmodia, in particular against
Plasmodium falciparum, can be determined according to methods known
per se, for example according to the method described in Example
6.
[0030] Inhibitory constants of the following order of magnitude are
shown for compounds of formula I:
[0031] EC.sub.50 (concentration showing half the maximum inhibitory
efficacy versus controls not given active substance): 1 to 200,
preferably 1 to 20 nmol/l.
[0032] EC.sub.99 (concentration showing half the maximum inhibitory
efficacy versus controls not given active substance): 10 to 1000,
preferably 10 to 110 nmol/l.
[0033] This in vitro model of Plasmodium falciparum has a high
predictive value for clinical efficacy in falciparum malaria.
[0034] The invention relates also to combinations of a compound of
formula I, or a salt thereof, with one or more other pharmaceutical
active substances, in particular with one or more other compounds
showing antiprotozoan activity, for example with quinine, a
quinoline methanol (such as mefloquine=Lariam.RTM.), a phenanthrene
methanol, such as halofantrine, a 4-aminoquinoline, such as
chloroquine or amodiaquine, an 8-aminoquinoline, such as pamaquine
or primaquine, an acridine, such as quinacrine, a pyrimidine, such
as dihydropteroic acid or dihydrofolic acid, a pyrimethamine
derivative, such as pyrimethamine or trimethoprim, a sulfonamide,
such as sulfadoxine (=Fanasil), a biguanide, such as chloroguanide,
a dihydrotriazine, such as cycloguanil, a sulfone, such as dapsone
(DDS), benflumetol or an analogue thereof or in particular
artemisin or an artemisin derivative, such as especially artemether
(=[3R-(3a, 5ab, 6b, 8ab, 9a, 10a,
12b,-12aR)]-decahydro-10-methoxy-3,6,9--
trimethyl-3,12-epoxy-12H-pyrano[4,3j]-1,2-benzodioxepin); or in
each case a salt thereof, if at least one salt-forming group is
present.
[0035] The invention relates also to a product comprising (kit of
parts) (a) an active substance of formula I, or a salt thereof, and
(b) as further active components one or more other active
substances (or in each case a salt thereof, provided at least one
salt-forming group is present), in particular one or more other
compounds with antiprotozoan activity, for example quinine, a
quinoline methanol (such as mefloquine=Lariam.RTM.), a phenanthrene
methanol, such as halofantrine, a 4-aminoquinoline, such as
chloroquine or amodiaquine, an 8-aminoquinoline, such as pamaquine
or primaquine, an acridine, such as quinacrine, a pyrimidine, such
as dihydropteroic acid or dihydrofolic acid, a pyrimethamine
derivative, such as pyrimethamine or trimethoprim, a sulfonamide,
such as sulfadoxine (=Fanasil), a biguanide, such as chloroguanide,
a dihydrotriazine, such as cycloguanil, a sulfone, such as dapsone
(DDS), benflumetol or an analogue thereof or in particular
artemisin or an artemisin derivative, such as especially artemether
(=[3R-(3a, 5ab, 6b, 8ab, 9a, 10a,
12b,-12aR)]-decahydro-10-methoxy-3,6,9--
trimethyl-3,12-epoxy-12H-pyrano[4,3j]-1,2-benzodioxepin), or in
each case a salt thereof, provided at least one salt-forming group
is present, in the presence or absence in each case of one or more
pharmaceutically acceptable carrier materials as a combination
product for administration simultaneously or at different times to
a warm-blooded animal, in particular a human, in particular for
administration in a regimen staggered in time such that the
therapeutic efficacy against said diseases is mutually potentiated
by the components administered as (a) and (b) compared with the
efficacy of the individual components. The formulations of the
individual active substances or fixed combinations correspond to
those stated under "Pharmaceutical formulations".
[0036] With the groups of preferred compounds of formula I
mentioned hereinafter, definitions of substituents from the general
definitions mentioned hereinbefore may reasonably be used, for
example, to replace more general definitions with more specific
definitions or especially with definitions characterized as being
preferred; in each case, the definitions described hereinbefore as
being preferred or exemplary are preferred.
[0037] A compound of formula I is preferred wherein R is
unsubstituted or mono-, di-, or trisubstituted
C.sub.1-C.sub.8alkyl, the substituents being selected from amino,
hydroxy and guanidino and not bonded in position 1 of the alkyl
radical, and X is halogenphenyl, in particular 4-chorophenyl, or a
salt thereof.
[0038] Stronger preference is for a compound of formula I wherein R
is C.sub.1-C.sub.8alkyl, in particular methyl, n-butyl, sec-butyl,
n-pentyl or n-octyl, and X is 4-chlorophenyl, or a salt
thereof.
[0039] Particular preference is for a compound of formula I wherein
R is pentyl or butyl, in particular n-butyl, sec-butyl or n-pentyl,
and X is 4-chlorophenyl, or a salt thereof.
[0040] Strongest preference is for a compound of formula I wherein
R is n-butyl and X is 4-chlorophenyl, or a salt thereof.
[0041] The invention relates especially to the compounds and
methods described in the examples, and to pharmaceutical
compositions and methods for their preparation.
[0042] The invention relates very especially to a compound of
formula I, in particular to a compound of formula I defined
hereinbefore as being preferred, in essentially pure form.
Preparation Processes
[0043] The compounds of formula I, or salts thereof, can be
prepared according to methods which are known per se, but which are
novel at least by virtue of the novelty of the compounds of formula
I, especially by either
[0044] a) condensing a compound of formula II, 4
[0045] wherein R is as defined for a compound of formula I, with an
aldehyde of formula III, 5
[0046] wherein X is as defined for compounds of formula I, or
[0047] b) adding to an oxiran of formula IV 6
[0048] wherein X is as defined for compounds of formula I, an amine
of formula V, 7
[0049] wherein R is as defined for a compound of formula I,
[0050] wherein any free functional groups which are present in one
of the educts of formula II in method a) or in one of the educts of
formula IV and/or V in method b), and which are not supposed to
take part in the reaction, are present in protected form if
necessary, and any protecting groups present are removed;
[0051] and, if so desired, reacting any free compound of formula I
resulting from the procedures described under a) or b) to form its
salt or any resulting salt of a compound of formula I to form
either a free compound of formula I or another salt of a compound
of formula I, or separating into its isomers a compound of formula
I that is present as an isomeric mixture.
Detailed Description of the Preferred Process Steps
[0052] Method a) The reaction preferably takes place in the
presence of a base, for example a basic metal hydroxide, such as an
alkali metal hydroxide, preferably sodium hydroxide, especially at
a temperature between 0.degree. C. and the reflux temperature of
the reaction mixture, especially at about 20 to 40.degree. C., in a
suitable solvent, such as an anhydrous alcohol, for example
ethanol.
[0053] Method b) The reaction preferably takes place in a suitable
solvent, for example an alcohol, such as ethanol or preferably
2-propanol, especially at elevated temperature, for example between
25.degree. C. and the reflux temperature of the reaction mixture,
especially at reflux temperature.
Protecting Groups
[0054] If one or more additional functional groups, for example
carboxy, hydroxy, amino or mercapto, have to be present in a
compound of formula II or a compound of formula IV and/or V in
protected form, because they are not supposed to take part in the
reaction, one or more of the protecting groups usually used in
synthesis are added. The protecting groups may already be present
in precursors and should protect the functional groups concerned
against unwanted secondary reactions, such as acylations,
etherifications, esterifications, oxidations, solvolysis, and
similar reactions. These protecting groups may already be present
at the precursor stage and are intended to protect the functional
groups concerned against unwanted secondary reactions such as
acylation, etherification, esterification, oxidation, solvolysis
etc. It is a characteristic of protecting groups that they lend
themselves readily, i.e. without undesired secondary reactions, to
removal, typically by solvolysis, reduction, photolysis or also by
enzyme activity, for example under conditions analogous to
physiological conditions, and that they are not present in the
end-products. A person skilled in the art knows, or can easily
establish, which protecting groups are suitable with the reactions
mentioned hereinabove and hereinafter.
[0055] The protection of functional groups by such protecting
groups, the protecting groups themselves, and their cleavage
reactions are described for example in standard reference works,
such as J. F. W. McOmie, "Protective Groups in Organic Chemistry",
Plenum Press, London and New York 1973, in T. W. Greene,
"Protective Groups in Organic Synthesis", Wiley, New York 1981, in
"The Peptides"; Volume 3 (editors: E. Gross and J. Meienhofer),
Academic Press, London and New York 1981, in "Methoden der
organischen Chemie" (Methods of organic chemistry), Houben Weyl,
4th edition, Volume 15/I, Georg Thieme Verlag, Stuttgart 1974, in
H.-D. Jakubke and H. Jescheit, "Aminosuren, Peptide, Proteine"
(Amino acids, peptides, proteins), Verlag Chemie, Weinheim,
Deerfield Beach, and Basel 1982, and in Jochen Lehmann, "Chemie der
Kohlenhydrate: Monosaccharide und Derivate" (Chemistry of
carbohydrates: monosaccharides and derivatives), Georg Thieme
Verlag, Stuttgart 1974.
[0056] Protecting groups which are not components of the desired
end-product of formula I, typically the carboxy, amino, and/or
hydroxy protecting groups, are removed in a manner known per se,
for example by solvolysis, especially hydrolysis, alcoholysis, or
acidolysis, or by reduction, especially by hydrogenolysis or other
methods of reduction, as well as photolysis, where applicable in
gradual steps or simultaneously; enzymatic methods may also be
used. The removal of protecting groups is described for example in
the reference works mentioned hereinabove in the section on
"Protecting groups".
Further Process Measures
[0057] Stereoisomeric mixtures, e.g. mixtures of diastereomers, can
be separated into their corresponding isomers in a manner known per
se by means of suitable separation methods. Diastereomeric mixtures
for example may be separated into their individual diastereomers by
means of fractionated crystallization, chromatography, and/or
solvent distribution. This separation may take place either at the
level of one of the starting compounds or in a compound of formula
I itself. Enantiomers may be separated through the formation of
diastereomeric salts, for example by salt formation with an
enantiomer-pure chiral acid, or by means of chromatography, for
example by HPLC, using chromatographic substrates with chiral
ligands.
[0058] Salts of compounds of formula I with one salt-forming group
may be prepared in a manner known per se. Acid addition salts of
compounds of formula I may thus be obtained for example by
treatment with an acid or with a suitable anion exchange
reagent.
[0059] Salts can be reacted to form free compounds in customary
manner, for example by treating with a suitable basic agent, for
example with alkali metal carbonates, hydrogen carbonates or
hydroxides, for example potassium carbonate or sodium hydroxide, or
they may be converted to other salts, for example by
crystallization from a solution in the presence of an acid with an
anion other than that of the original acid addition salt from a
suitable solvent.
General Process Conditions
[0060] All process steps described here can be carried out under
reaction conditions known per se, preferably under those
specifically mentioned, in the absence of or usually in the
presence of solvents or diluents, preferably such as are inert to
the reagents used and able to dissolve these, in the absence or
presence of catalysts, condensing agents or neutralizing agents,
depending on the type of reaction and/or reactants at reduced,
normal, or elevated temperature, for example in the range from
-100.degree. C. to about 190.degree. C., preferably from about
-80.degree. C. to about 150.degree. C., for example at -80 to
-60.degree. C., at room temperature, at -20 to 40.degree. C. or at
the boiling point of the solvent used, under atmospheric pressure
or in a closed vessel, if need be under pressure, and/or in an
inert, for example an argon or nitrogen, atmosphere.
[0061] Salts of all starting compounds and intermediates may be
used if these contain salt-forming groups. Salts may also be
present during the reaction of such compounds, provided the
reaction is not thereby disturbed.
[0062] At all reaction stages, isomeric mixtures that occur can be
separated into their individual isomers, e.g. diastereomers or
enantiomers, or into any mixtures of isomers, e.g. racemates or
diastereomeric mixtures, typically as described under "Further
process steps".
[0063] The solvents from which those suitable for the reaction in
question may be selected include for example water, esters, such as
lower alkyl-lower alkanoates, for example diethyl acetate, cyclic
ethers, for example tetrahydrofuran, alcohols, such as methanol,
ethanol or 1 or 2-propanol, nitriles, such as acetonitrile, acid
amides, such as dimethylformamide, bases, such as heterocyclic
nitrogen bases, for example pyridine, or mixtures of these
solvents, for example aqueous solutions, unless otherwise indicated
in the description of the method. Such solvent mixtures may also be
used in processing, for example through chromatography or
distribution.
[0064] The invention relates also to those forms of the process in
which one starts from a compound obtainable at any stage as an
intermediate and carries out the missing steps, or breaks off the
process at any stage, or forms a starting material under the
reaction conditions, or uses said starting material in the form of
a reactive derivative or salt, or produces a compound obtainable by
means of the process according to the invention and processes the
said compound in situ. In the preferred embodiment, one starts from
those starting materials which lead to the compounds described
hereinabove as preferred, particularly as especially preferred,
primarily preferred, and/or preferred above all.
[0065] The compounds of formula I, including their salts, are also
obtainable in the form of hydrates, or their crystals may include
for example the solvent used for crystallization (present as
solvates).
[0066] In the preferred embodiment, a compound of formula I is
prepared according to the processes and process steps defined in
the Examples.
Pharmaceutical Compositions and their Preparation, Use of Compounds
of Formula I
[0067] The present invention relates likewise to pharmaceutical
compositions which comprise as active substance a compound of
formula I and can be used in particular for the treatment and
prophylaxis of the diseases defined in the background to the
invention, such as a protozoal infection or a trematode infection,
primarily malaria, especially Malaria tropica. Compositions for
enteral administration, such as nasal, buccal, rectal or,
especially, oral administration, and for parenteral administration,
such as intravenous, intramuscular or subcutaneous administration,
to warm-blooded animals, especially humans, are especially
preferred. The compositions comprise the active ingredient alone
or, preferably, together with one or more pharmaceutically
acceptable carriers. The dosage of the active ingredient depends
upon the disease to be treated and upon the species, its age,
weight, and individual condition, the individual pharmacokinetic
data, and the mode of administration.
[0068] The invention relates also to pharmaceutical compositions
for use in a method for the prophylactic or especially therapeutic
management of the human or animal body, to a process for the
preparation thereof (especially in the form of compositions for the
treatment of malaria) and to a method of prophylactic or
therapeutic treatment of the diseases stated hereinbefore
(especially in the previous paragraph), primarily of malaria,
especially Malaria tropica. The invention relates also to processes
and to the use of compounds of formula I for the preparation of
pharmaceutical preparations which comprise as active component
(active ingredient) compounds of formula I.
[0069] Preference is given to a pharmaceutical composition that is
suitable for administration to a warm-blooded animal, especially a
human, suffering from a disease that is attributable to a protozoal
or trematode infection, especially malaria, such as Malaria
tropica, comprising a compound of formula I, or a pharmaceutically
acceptable salt thereof if salt-forming groups are present, in an
amount effective for the prophylactic or therapeutic treatment of
this disease, together with at least one pharmaceutically
acceptable carrier.
[0070] The pharmaceutical compositions comprise from approximately
1% to approximately 95% of active ingredient, single-dose
administration forms comprising in the preferred embodiment from
approximately 10% to approximately 90% of active ingredient and
forms that are not of single-dose type comprising in the preferred
embodiment from approximately 5% to approximately 20% of active
ingredient. Unit dose forms are, for example, coated and uncoated
tablets, ampoules, vials, suppositories, or capsules. Further
dosage forms are, for example, ointments, creams, pastes, foams,
tinctures, lip-sticks, drops, sprays, dispersions, etc. Examples
are capsules containing from about 0.05 g to about 1.0 g of active
ingredient.
[0071] The pharmaceutical compositions of the present invention are
prepared in a manner known per se, for example by means of
conventional mixing, granulating, coating, dissolving or
lyophilizing processes.
[0072] Preference is given to the use of solutions of the active
ingredient, and also suspensions or dispersions, especially
isotonic aqueous solutions, dispersions or suspensions which, for
example in the case of lyophilized compositions comprising the
active ingredient on its own or together with a carrier, for
example mannitol, can be made up before use. The pharmaceutical
compositions may be sterilized and/or may comprise excipients, for
example preservatives, stabilizers, wetting agents and/or
emulsifiers, solubilizers, salts for regulating the osmotic
pressure and/or buffers and are prepared in a manner known per se,
for example by means of conventional dissolving and lyophilizing
processes. The said solutions or suspensions may comprise
viscosity-increasing agents, typically sodium
carboxymethylcellulose, carboxymethylcellulose, dextran,
polyvinylpyrrolidone, or gelatins, or also solubilizers, for
example .RTM.Tween 80 [polyoxyethylen(20)sorbitan mono-oleate;
trademark of ICI Americas, Inc, USA].
[0073] Suspensions in oil comprise as the oil component the
vegetable, synthetic, or semi-synthetic oils customary for
injection purposes. Especially suitable for such purposes are
liquid fatty acid esters comprising as the acid component a
long-chained fatty acid having from 8 to 22, especially from 12 to
22, carbon atoms, for example lauric acid, tridecylic acid,
myristic acid, pentadecylic acid, palmitic acid, margaric acid,
stearic acid, arachidic acid, behenic acid or corresponding
unsaturated acids, for example oleic acid, elaidic acid, erucic
acid, brassidic acid or linoleic acid, if desired with the addition
of antioxidants, for example vitamin E, .beta.-carotene or
3,5-di-tert-butyl-4-hydroxytoluene. The alcohol component of these
fatty acid esters has a maximum of 6 carbon atoms and is a mono- or
polyhydric, for example a mono-, di- or trihydric, alcohol, for
example methanol, ethanol, propanol, butanol or pentanol or the
isomers thereof, but especially glycol and glycerol. The following
are therefore examples of suitable fatty acid esters: ethyl oleate,
isopropyl myristate, isopropyl palmitate, polyoxyethylene glycerol
trioleate, unsaturated polyglycolized glycerides prepared by
alcoholysis of apricot seed oil and constituted from glycerides and
polyethylene glycol ester; saturated polyglycolized glycerides
prepared by alcoholysis of TCM and constituted from glycerides and
polyethylene glycol ester and/or triglycerides of saturated fatty
acids of chain length C.sub.8 to C.sub.12, but especially vegetable
oils such as cottonseed oil, almond oil, olive oil, castor oil,
sesame oil, soybean oil and more especially groundnut oil.
[0074] The manufacture of injectable preparations is usually
carried out under sterile conditions, as is the filling, for
example, into ampoules or vials, and the sealing of the
containers.
[0075] Pharmaceutical compositions for oral administration can be
obtained, for example, by combining the active ingredient with one
or more solid carriers, if need be granulating a resulting mixture,
and processing the mixture or granules, if desired, to form tablets
or tablet cores, if need be by the inclusion of additional
excipients.
[0076] Suitable carriers are especially fillers, such as sugars,
for example lactose, saccharose, mannitol or sorbitol, cellulose
preparations, in particular microcrystalline cellulose, and/or
calcium phosphates, for example tricalcium phosphate or calcium
hydrogen phosphate, and also binders, such as starches, for example
corn, wheat, rice or potato starch, methylcellulose, hydroxypropyl
methylcellulose, sodium carboxymethylcellulose, and/or
polyvinylpyrrolidone, and/or, if desired, disintegrators, such as
the above-mentioned starches, also carboxymethyl starch,
crosslinked polyvinylpyrrolidone, alginic acid or a salt thereof,
such as sodium alginate. Additional excipients are especially flow
conditioners and lubricants, for example silicic acid, talc,
stearic acid or salts thereof, such as magnesium or calcium
stearate, and/or polyethylene glycol, or derivatives thereof.
[0077] Tablet cores may be provided with suitable, if need be
enteric, coatings, using inter alia concentrated sugar solutions
which may comprise gum arabic, talc, polyvinylpyrrolidone,
polyethylene glycol and/or titanium dioxide, or coating solutions
in suitable organic solvents or solvent mixtures, or, for the
preparation of enteric coatings, solutions of suitable cellulose
preparations, such as acetylcellulose phthalate or
hydroxypropylmethylcellulose phthalate. Dyes or pigments may be
added to the tablets or tablet coatings, for example for
identification purposes or to indicate different doses of active
ingredient.
[0078] Orally administrable pharmaceutical compositions also
include hard capsules consisting of gelatin, and also soft, sealed
capsules consisting of gelatin and a plasticizer, such as glycerol
or sorbitol. The hard capsules may contain the active ingredient in
the form of granules, for example in admixture with fillers, such
as corn starch, binders, and/or glidants, such as talc or magnesium
stearate, and if need be stabilizers. In soft capsules, the active
ingredient is preferably dissolved or suspended in suitable liquid
excipients, such as fatty oils, paraffin oil or liquid polyethylene
glycols or fatty acid esters of ethylene or propylene glycol, to
which stabilizers and detergents, for example of the
polyoxyethylene sorbitan fatty acid ester type, may also be
added.
[0079] Other oral dosage forms are, for example, syrups prepared in
customary manner which comprise the active ingredient, for example,
in suspended form and in a concentration of about 5% to 20%,
preferably about 10%, or in a similar concentration that provides a
suitable single dose, for example, when administered in measures of
5 or 10 ml. Also suitable are, for example, powdered or liquid
concentrates for the preparation of shakes, for example in milk.
Such concentrates may also be packaged in single dose
quantities.
[0080] Suitable rectally administrable pharmaceutical compositions
are, for example, suppositories that comprise a combination of the
active ingredient and a suppository base. Suitable suppository
bases are, for example, natural or synthetic triglycerides,
paraffin hydrocarbons, polyethylene glycols or higher alkanols.
[0081] The aqueous solutions suitable for parenteral administration
are especially those of an active ingredient in water-soluble form,
for example in the form of a water-soluble salt, or aqueous
injection suspensions that contain viscosity-increasing substances,
for example sodium carboxymethylcellulose, sorbitol and/or dextran,
and, if need be, stabilizers. The active ingredient, if need be
together with excipients, can also be in the form of a lyophilizate
and can be made into a solution before parenteral administration by
the addition of suitable solvents.
[0082] Solutions such as are used, for example, for parenteral
administration can also be employed as infusion solutions.
[0083] Preferred preservatives are, for example, antioxidants, such
as ascorbic acid, or microbicides, such as sorbic acid or benzoic
acid.
[0084] The invention likewise relates to a process or a method of
therapeutic or prophylactic treatment of the disease conditions
defined hereinbefore, in particular malaria, more especially
Malaria tropica. The compounds of formula I can be administered as
such or in the form of pharmaceutical compositions,
prophylactically or therapeutically, preferably in an amount
effective against the said diseases, to a warm-blooded animal
requiring such treatment, for example to a human, the compounds
especially being used in the form of pharmaceutical compositions.
In the case of an individual having a bodyweight of about 70 kg the
daily dosage administered is from approximately 0.01 g to
approximately 5 g, preferably from approximately 0.05 g to
approximately 2 g, of a compound of the present invention,
preferably divided into 3 to 5, especially 4, separate doses.
[0085] The present invention relates especially also to the use of
a compound of formula I , or a pharmaceutically acceptable salt
thereof, especially a compound of formula I or a pharmaceutically
acceptable salt thereof which is said to be preferred, as such or
in the form of a pharmaceutical formulation with at least one
pharmaceutically acceptable carrier for the therapeutic or
prophylactic treatment of one or more of the diseases stated
hereinbefore, especially malaria, more especially Malaria
tropica.
[0086] The preferred dose quantity, composition, and preparation of
pharmaceutical formulations (medicines) which are to be used in
each case are described above.
[0087] A compound of formula I, or a salt thereof, (=component (a))
may be formulated or used in the said pharmaceutical compositions,
processes for the preparation of pharmaceutical compositions,
methods and/or uses alone or in combination with one or more other
active ingredients (component(s) (b)), especially those mentioned
in the background to the invention, components (a) and (b) being
formulated in combinations either together in a fixed combination
or separately in a product comprising (kit of parts) (a) an active
ingredient of formula I, or a salt thereof, and (b) as further
active component one or more additional active ingredients, as
defined hereinbefore, especially for administration in a regimen
staggered in time such that the therapeutic efficacy against said
diseases is mutually potentiated by the components administered as
(a) and (b) compared with the efficacy of the components
administered separately.
Starting Materials
[0088] New starting materials and/or intermediates, as well as
processes for the preparation thereof, are likewise the subject of
this invention. In the preferred embodiment, such starting
materials are used and reaction conditions so selected as to enable
the preferred compounds to be obtained.
[0089] The subject of the present invention is in particular a
starting material of formula II, wherein R has the meaning given in
the definition of a compound of formula I. Preference is for a
compound of formula II in which R is as defined for the compounds
of formula I which are stated to be preferred. A compound of
formula II wherein R is butyl, in particular n-butyl, is especially
preferred.
[0090] The starting material of formula II can be prepared from an
oxiran of formula VI, 8
[0091] by reacting this in a manner analogous to the conditions
stated under method b) with, instead of the oxiran of formula IV
stated therein, an amine of formula V as defined therein.
[0092] The oxiran of formula IV can be prepared from an oxiran of
formula VI, as shown hereinbefore, by reaction with an aldehyde of
formula III, as defined hereinbefore under method a), in a manner
analogous to the conditions stated under method a), when a compound
of formula VI is used instead of a compound of formula II.
[0093] A compound of formula VI is known or prepared according to
methods known per se (see for example the Chinese patent
application CN 104 45 35 A (published on May 30, 1990) or Atkinson
et al., J. Med. Chem. 11, 1223 (1968) and Atkinson et al., J. Med.
Chem. 17, 1009 (1974)).
[0094] Amines of formula V and aldehydes of formula III are known,
capable of being prepared according to methods known per se, or
commercially obtainable.
EXAMPLES
[0095] The following Examples serve to illustrate the invention
without limiting the scope thereof.
[0096] Starting Materials 4 (see Table 1):
[0097] A) 2-Methylamino-1-(2,7-dichloro-9H-fluoren-4yl)ethanol
(4a)
[0098] A mixture of 5.0 g 2,7-dichloro-9H-fluoren-4-oxiran (1), 25
g methylamine (33% solution in ethanol) and 20 ml ethanol is
refluxed for 2 days. The reaction mixture is cooled to room
temperature and filtered. The filter cake is washed with ethanol
and dried under a vacuum, and a mixture of 4a and
bis-[2-(2,7-dichloro-9H-fluoren-4-yl)-2-hydroxy]ethylme- thylamine
obtained: .sup.1H-NMR (300 MHz, CDCl.sub.3): 2.4 and 2.55
(two-singlets, N--CH.sub.3, in each case 4a and
bis-[2-(2,7-dichloro-9H-f-
luoren-4-yl)-2-hydroxy]ethylmethylamine); 2.6-3.0 (m, CH.sub.2--N);
3.8 and 3.9 (two singlets, C-9-H of fluorenyl groups); 5.4 and 5.5
(two double doublets, CH--O); 7.1-7.7 (m, aromatic protons).
[0099] The following starting materials are prepared in an
analogous manner (see Table 1)
[0100] B) 2-n-Butylamino-1-(2,7-dichloro-9H-fluoren-4yl)ethanol
(4b):
[0101] (with n-butylamine instead of methylamine as educt)
.sup.1H-NMR (200 Mhz, CDCl.sub.3): 0.9 (t, 3H, CH.sub.3--CCC--N);
1.2-1.6 (m, 4H, CH.sub.2--CH.sub.2--C--N); 2.6-2.8 (m, 3H,
CH--N--CH.sub.2); 3.1 (dd, 12 Hz, 3 Hz, 1H, CH--N); 3.9 (s, 2H,
C-9-H); 5.4 (dd, 1H, 4 Hz, 8 Hz, CH--O); 7.3-7.8 (m, 5H).
[0102] C) 2-n-Hexylamino-1-(2,7-dichloro-9H-fluoren-4yl)ethanol
(4d):
[0103] (with n-hexylamine instead of methylamine as educt)
.sup.1H-NMR (300 Mhz, CDCl.sub.3): 0.8 (t, 3H,
N--C--C--C--C--C--CH.sub.3); 1.1-1.3 (m, 6H,
N--C--C--CH.sub.2CH.sub.2CH.sub.2--C); (1.4, m, 2H,
N--C--CH.sub.2--); 2.5-2.7 (m, 3H, CH--N--CH.sub.2); 2.95 (dd, 1H,
CH--N); 3.75 (s, 2H, C-9-H); 5.35 (dd, 1H, O--CH--); 7.25 (d with
long range coupling, 8 Hz, 1H, C-6-H); 7.32, 7.43 (two singlets
with long range coupling, 1H, 1H, C-1-H, C-3-H); 7.56 (s with long
range coupling, 1H, C-8-H); 7.58 (d, 8 Hz, C-5-H).
[0104] D) 2-n-Octylamino-1-(2,7-dichloro-9H-fluoren-4yl)ethanol
(4e):
[0105] (with n-octylamine instead of methylamine as educt)
.sup.1H-NMR (300 Mhz, CDCl.sub.3): 0.8 ppm (t, 3H, CH.sub.3);
1.1-1.3 (m, 10H, NCC(CH.sub.2).sub.5--C); 1.4 (m, 2H,
N--C--CH.sub.2--); 2.5-2.7 (m, 3H, CH--N--CH.sub.2); 3.0 (dd, 1H,
CH--N); 3.8 (s, 2H, C-9-H); 5.35 (dd, 1H, O--CH--); 7.25 (d with
long range coupling, 8 Hz, 1H, C-6-H); 7.58 (s with long range
coupling, 1H, C-8-H); 7.60 (d, 8 Hz, C-5-H).
[0106] E)
2-[2-(2-Hydroxy)ethoxy]ethylamino-1-(2,7-dichloro-9H-fluoren-4yl-
)ethanol (4f):
[0107] (with 2-(2-aminoethoxy)ethanol (Fluka, Buchs, Switzerland)
as educt instead of methylamine)
[0108] .sup.1H-NMR (300 MHz, CDCl.sub.3): 2.0 ppm (broad, 1H, OH);
2.7-3.0 (m, 4H, CH.sub.2NCH.sub.2); 3.6 (m, 4H,
C--CH.sub.2OCH.sub.2--C); 3.75 (m, 2H, CH.sub.2--OH); 3.85 (s, 2H,
C-9-H); 5.5 (dd, 1H, O--CH); 7.3 (dm, 1H, C-6-H); 7.4 and 7.5 (two
s, in each case 1H, C-1,3-H); 7.65 (split s, 1l H, C-8-H); 7.7 (d,
1H, C-5-H).
1TABLE 1 Starting materials Structure R = 9 4a CH.sub.34b
CH.sub.2CH.sub.2CH.sub.2CH.sub.34c
CH.sub.2CH.sub.2CH.sub.2HC.sub.2CH.sub.34d
CH.sub.2CH.sub.2CH.sub.2CH.sub- .2CH.sub.2CH.sub.34e
CH.sub.2CH.sub.2CH.sub.2CH.sub.2CH.sub.2CH.sub.2CH.su-
b.2CH.sub.34f CH.sub.2CH.sub.2--O--CH.sub.2CH.sub.2--OH
EXAMPLES
(End-Products) (See Table 2)
Example 1
2-Methylamino-1-[2,7-dichloro-9-(4-chlorobenzylidene)-9H-fluoren-4yl]ethan-
ol (5a)
[0109] Preparation analogous to that under Example 2, starting from
4a instead of 4b. .sup.1H-NMR (300 MHz, CDCl.sub.3): 2.3 ppm (broad
s, 3H, N--CH.sub.3); 1.3-2.0 (broad s, 2H, NH, OH); 2.45-2.6 (m,
1H, CH--N); 2.7-2.85 (m, 1H, CH--N), 5.2 (br. d, 1H, CH--O);
7.0-7.6 (m, 10H).
Example 2
"N-Desbutyl
benflumetol"=2-n-butylamino-1-[2,7-dichloro-9-(4-chlorobenzyli-
dene)-9H-fluoren-4yl]ethanol (5b)
[0110] A suspension of 6.47 g 4b in 123 ml absolute ethanol is
treated with 4.28 g 4-chlorobenzaldehyde and 0.78 g sodium
hydroxide. The suspension is agitated for 30 hours at 30.degree. C.
The mixture is filtered, the filter cake washed with ethanol and
dried under a vacuum, the N-desbutyl benflumetol being obtained as
a mixture of isomers (E, Z). .sup.1H-NMR (200 Mhz, C.sub.6D.sub.6):
0.8 ppm (m, 3H, CH.sub.3); 1.2 (m, 4H, N--C--CH.sub.2CH.sub.2--C);
2.2-2.4 (m, 2H, O--C--C-N--CH.sub.2); 2.4-2.6 (m) and 2.75 (dd) je
1H (O--C--CH.sub.2--N); 5.4 (dd, 9 Hz, 2.7 Hz, 1H, CH--O); 7.0-8.1
(m, 10H).
Example 3
2-n-Octylamino-1-[2,7-dichloro-9-(4-chlorobenzylidene)-9H-fluoren-4yl]etha-
nol (5e)
[0111] Preparation analogous to that under Example 2 starting from
4e instead of 4b; after purification on silica gel (eluant:
toluene/ethanol 19:1, v/v) the title is obtained as an oil which
crystallizes out when left to stand: .sup.1H-NMR (300 MHz,
CDCl.sub.3): 0.8 ppm (t, 3H, CH.sub.3); 1.2 (s br., 10H,
N--CC--(CH.sub.2).sub.5--C); 1.4 (m, 2H, N--C--CH.sub.2--); 1.6-2.3
(br., 2H, NH, OH); 2.5-2.7 (m, 3H, CH--N--CH.sub.2); 2.95 (dd, 1H,
CH--N); 5.3 (m, 1H, O--CH); 7.2-7.7 (m, 10H, aromatic and vinylic
CH).
Example 4
2-[2-(2-Hydroxy)ethoxy]ethylamino-1-[2,7-dichloro-9-(4-chlorobenzylidene)--
9H-fluoren-4yl]ethanol (5f)
[0112] Preparation analogous to that under Example 2 starting from
4f instead of 4b; title compound (obtained after chromatography on
silica gel column, eluant toluene/ethanol 9:1, v/v): .sup.1H-NMR
(300 Mhz, CDCl.sub.3): 1.5-2.2 ppm (br., 3H, OH, NH); 2.5-3.0 (m,
4H, CH.sub.2--N--CH.sub.2); 3.5 (m, 4H, CH.sub.2--O--CH.sub.2); 3.7
(m, 2H, CH.sub.3--OH); 5.4 (d, br., 1H, Ar--CH--O); 7.3-7.8 (m,
10H, aromatic and vinylic CH).
Example 5
2-n-Pentylamino-1-[2,7-dichloro-9-(4-chlorobenzylidene)-9H-fluoren-4yl]eth-
anol (5c)
[0113] A mixture of 0.76 g
2,7-dichloro-9-(4-chlorobenzylidene)-9H-fluoren- -4-oxiran, 0.77 g
n-pentylamine and 7 g 2-propanol is refluxed for 26 hours. The
mixture is cooled and agitated for a further two days at room
temperature. The product is filtered off, washed with 2-propanol,
and dried under a vacuum: .sup.1H-NMR (300 MHz, CDCl.sub.3): 0.8
ppm (t, 3H, CH.sub.3); 1.2 (m, 4H, O--C--C--CH.sub.2CH.sub.2--C);
1.4 (m, 2H, O--C--CH.sub.2--CCC); 1.6-2.4 (br., 2H, NH, OH);
2.5-2.7 (m, 3H, CH--N--CH.sub.2); 3.0 (dd, 1H, CH--N); 5.3 (dd, 1H,
O--CH); 7.2-7.7 (m, 10H, aromatic and vinylic CH).
[0114] The starting material is prepared as follows:
[0115] 5a) 2,7-Dichloro-9-(4-chlorobenzylidene)-9H-fluoren-4-oxiran
2:
[0116] A mixture of 20 g 2,7-dichloro-9H-fluoren-4-oxiran, 17.7 g
4-chlorobenzaldehyde, 500 ml ethanol and 27.5 g sodium hydroxide is
agitated for 18 hours at 25.degree. C. (initially under cooling).
The yellow solid substance obtained is filtered off, washed with
water, and the title compound thus obtained. .sup.1H-NMR (300 MHz,
CDCl.sub.3): 2.8 and 3.4 (td, t, in each case 1H, oxiran
--CH.sub.2O--); 4.4 (br. s, 1H, Ar--CH(--C)--O); 7.3-7.8 (m, 10H,
aromatic and vinylic CH including br. s at 7.5 ppm for
C.sub.6H.sub.4--Cl).
2TABLE 2 Examples Structure R = 10 5a CH.sub.35b
CH.sub.2CH.sub.2CH.sub.2CH.sub.35c
CH.sub.2CH.sub.2CH.sub.2CH.sub.2CH.sub.35d
CH.sub.2CH.sub.2CH.sub.2CH.sub- .2CH.sub.2CH.sub.35e
CH.sub.2CH.sub.2CH.sub.2CH.sub.2CH.sub.2CH.sub.2CH.su-
b.2CH.sub.35f CH.sub.2CH.sub.2--O--CH.sub.2CH.sub.2--OH
Example 6
Comparison of the Efficacy of Benflumetol
(2-(di-n-butylamino)-1-[2,7-dich-
loro-9-(4-chlorobenzylidene)-9H-fluoren-4-yl]ethanol and
2-alkylamino-1-[2,7-dichloro-9-(4-chlorobenzylidene]-9H-fluoren-4-yl)etha-
nols against Plasmodium falciparum in vitro:
[0117] The study is carried out in Mae Sot, a province in
north-west Thailand close to Myanmar. The Plasmodium falciparum
isolates used for the study come from patients who have clinically
manifest malaria and attend the VBC Unit Malaria Clinic in Mae Sot
for diagnosis and treatment. The test for efficacy is carried out
with blood samples obtained by finger pricks (in accordance with
the WHO Standard Microtest Method for studying the inhibition of
schizont maturation, see Wemsdorfer, W. H., and Payne, D. (1988),
Drug Sensitivity Tests. In: Wemsdorfer, W. H., and McGregor, I. A.
(Editors), Malaria: Principles and practice of malariology;
Churchill Livingstone, Edinburgh). The tests are carried out in
parallel with benflumetol and the 2-alkylamino-1-[2,7-dich-
loro-9-(4-chlorobenzylidene]-9H-fluoren-4-yl)ethanols in
concentrations between 3 and 3000 nmol/l in blood medium mixture
(BMM) using materials from the WHO Standard Test Kit supplied by
the WHO Regional Office for the Western Pacific, Manila, except for
the predosed microtitre plates, which are prepared in the
laboratory of the institute of Specific Prophylaxis and Tropical
Medicine, University of Vienna, Austria.
[0118] The procedure for determining parasitaemia before incubation
follows the WHO Standard Method (WHO (1991), Basic malaria
microscopy. Part I; WHO, Geneva). The schizont titres are
determined as described in Wemsdorfer and Payne (1988) (see
above).
[0119] The statistical analysis of the data was carried out
according to log-concentration/response probit analysis (Litchfield
& Wilcoxon (1949), J. Exp. Pharmacol. 89, 99-113). This method
is based on the least-squares procedure and is the most widely
accepted method for the analysis of dose-response studies. A
computer adaptation of the method (Wernsdorfer & Wernsdorfer,
Mitteilungen der sterreichischen Gesellschaft fur Tropenmedizin und
Parasitologie 17, 221-228) is used for data processing.
Results
Example 6.1
Comparison of the Efficacy of Benflumetol and N-desbutyl
Benflumetol (5b,
2-(n-butylamino)-1-[2,7-dichloro-9-(4-chlorobenzylidene)-9H-fluoren-4-yl]-
ethanol):
[0120] None of the 58 Plasmodium falciparum isolates studied shows
schizont maturation at concentrations of benflumetol above 300
nmol/l, and the great majority of isolates (97%) are completely
inhibited at 300 nmol/l benflumetol. Not one of the isolates shows
schizont maturation at a concentration of 300 nmol/l N-desbutyl
benflumetol, and the great majority of isolates are completely
inhibited even at 100 nml/l N-desbutyl benflumetol.
[0121] The response parameters for benflumetol are shown in Table 3
and those for N-desbutyl benflumetol in Table 4. The .chi..sup.2
for heterogeneity shows an acceptable agreement of the observed
data with the regression lines. This is also apparent in the
relatively narrow confidence limits (95%).
[0122] There are major differences in the sensitivity of isolates
to either benflumetol or n-desbutylbenflumetol, for example an
EC.sub.50 (dose producing 50% inhibition versus controls not given
active substance) of 24.44 nmol/l for benflumetol and 4.36 nmol/l
for n-desbutylbenflumetol. Similarly, the EC.sub.99 (99% inhibition
versus controls not given active substance), which is the most
important indicator for clinical efficacy of benflumetol (371.59
nmol/l) in non-immune persons is around 8 (eight) times higher than
that for n-desbutylbenflumetol (45.72 nmol/l).
[0123] Statistical comparison according to Litchfield &
Wilcoxon shows that the regression lines run parallel within the
limits of experimental error because the slope ratio (SR=1.1718) is
smaller than the factor of the slope ratio (f.sub.SR=1.3063). Since
the "power ratio" (PR= 5.6083) is also greater than the factor of
the power ratio (f.sub.PR=1.4849), the difference in efficacy
between benflumetol and n-desbutylbenflumetol is statistically
highly significant.
[0124] The 58 EC.sub.50 pairs are tested for correlation. With a
correlation coefficient of 0.7308, the result is highly significant
(p<0.000003). This applies also to the 58 EC.sub.90 pairs
(correlation coefficient 0.6768, p<0.00001).
3TABLE 3 Concentration-dependent inhibitory effect of benflumetol
on Plasmodium falciparum in vitro: Active substance Inhibition of
concentration (nmol/l) schizont maturation in % 3.0 7.14 10.0 20.44
30.0 47.16 100.0 90.72 300.0 99.79 1000.0 100.00 3000.0 100.00 n =
58; a = 2.2678; b = 0.8548; r = 0.9739; .chi..sup.2 = 5.6500 S =
3.2009; A = 1.2922; K = 6; N' = 116; R = 333.3333333 f.sub.s =
1.2193; f.sub.EC50 = 1.3488; f.sub.EC99 = 1.7399 EC.sub.50: mean
value = 24.4427 (95% confidence limits: lower 18.1217; upper
32.9685) EC.sub.99: mean value = 371.5908 (95% confidence limits:
lower 213.5703; upper 646.5307) y = 0.0997 + 1.8487; R.sup.2 =
0.534
[0125]
4TABLE 4 Concentration-dependent inhibitory effect of
N-desbutylbenflumetol (5b) on Plasmodium falciparum in vitro:
Active substance Inhibition of concentration (nmol/l) schizont
maturation in % 3.0 36.53 10.0 77.40 30.0 98.60 100.0 99.85 300.0
100.00 1000.0 100.00 3000.0 100.00 n = 58; a = 3.5431; b = 0.9897;
r = 0.9941; .chi..sup.2 = 0.6368 S = 2.7315; A = 1.2727; K = 5; N'
= 116; R = 100 f.sub.s = 1.1962; f.sub.EC50 = 1.2949; f.sub.EC99 =
1.6388 EC.sub.50: mean value = 4.3583 (95% confidence limits: lower
3.3658; upper 5.6436) EC.sub.99: mean value = 45.7213 (95%
confidence limits: lower 27.8989; upper 74.9291) Y = 0.0806x +
5.3769; R.sup.2 = 0.4581
Examples 6.2 and 6.3
[0126] In Examples 6.2 and 6.3, 34 Plasmodium falciparum isolates
are tested. None of the 34 Plasmodium falciparum isolates studied
shows schizont maturation at concentrations of benflumetol above
3000 nmol/l, and the great majority of isolates (96%) are
completely inhibited at 300 nmol/l benflumetol.
[0127] The isolates of patients 11, 39 and 47 proved as highly
resistant to mefloquine, resulting in an unacceptably high degree
of heterogeneity in the data (.chi..sup.2=16.153 at a maximum
permissible value of 11.1). There was a positive correlation
between sensitivity to mefloquine and sensitivity to benflumetol.
The response of these isolates to benflumetol and the tested
compounds was also relatively weak, this influence appearing to a
lesser extent on the tested compounds than on benflumetol. The
correlation of the response to specific pairs of active substances
at the EC.sub.50 and EC.sub.90 values was calculated with all
isolates. The compounds of Examples 6.2 and 6.3 proved more
effective than benflumetol in the present test.
5TABLE 5 Concentration-dependent inhibitory effect of benflumetol
on Plasmodium falciparum in vitro (34-isolate test series, Examples
6.2 and 6.3): Active substance Inhibition of concentration (nmol/l)
schizont maturation in % 3.0 7.16 10.0 18.40 30.0 42.75 100.0 90.74
300.0 96.25 1000.0 99.92 3000.0 100.00 n = 34; a = 2.3498; b =
0.7956; r = 0.9814; .chi..sup.2 = 3.6652 S = 3.4906; A = 1.2825; K
= 7; N' = 68; R = 1000 f.sub.s = 1.2952; f.sub.EC50 = 1.5218;
f.sub.EC99 = 2.0934 EC.sub.50: mean value = 27.9715 (95% confidence
limits: lower 13.3802; upper 42.5678) EC.sub.99: mean value =
520.7651 (95% confidence limits: lower 248.7678; upper
1090.1581)
Example 6.2
Comparison of the Efficacy of Benflumetol and
2-methylamino-1-[2,7-dichlor-
o-9-(4-chlorobenzylidene)-9H-fluoren-4-yl]ethanol (5a):
[0128] The response parameters for benflumetol are defined in Table
5 (see above) and those for compound 5a in Table 6. The .chi..sup.2
for heterogeneity shows an acceptable agreement between the data
observed and the regression lines.
[0129] Not one of the isolates shows schizont maturation at a
concentration of 1000 nmol/l 5a, and the great majority of isolates
(96%) are completely inhibited even at 100 nml/l.
[0130] There are major differences in the sensitivity of the
isolates to either benflumetol or compound 5a. For example, the
EC.sub.99 (99% inhibition versus controls not given active
substance), which is the most important indicator for clinical
efficacy of compound 5a (87.03 nmol/l) in non-immune persons,
amounts to only about one fifth of that for benflumetol (422.49
nmol/l), i.e. the same effect on Plasmodium falciparum was attained
with substance 5a at approximately one fifth the dose.
[0131] Statistical comparison according to Litchfield &
Wilcoxon shows that the regression lines run parallel within the
limits of experimental error because the slope ratio (SR=1.2483) is
smaller than the factor of the slope ratio (f.sub.SR=1.6193). Since
the "power ratio" (PR= 2.8898) is also greater than the factor of
the power ratio (f.sub.PR=1.9077), the difference in efficacy
between benflumetol and compound 5a is statistically
significant.
[0132] The 34 EC.sub.50 pairs are tested for correlation. With a
correlation coefficient of 0.6430, the result is significant. This
applies also to the 34 EC.sub.90 pairs with a correlation
coefficient of 0.7697.
6TABLE 6 Concentration-dependent inhibitory effect of
2-methylamino-1- [2,7-dichloro-9-(4-chlorobenzylidene)-9H-fluor-
en-4-yl]ethanol (5a) on Plasmodium falciparum in vitro: Active
substance Inhibition of concentration (nmol/l) schizont maturation
in % 3.0 13.12 10.0 51.92 30.0 83.14 100.0 95.81 300.0 97.06 1000.0
100.00 3000.0 100.00 n = 34; a = 3.3024; b = 0.7216; r = 0.9754;
.chi..sup.2 = 3.8764 S = 3.9675; A = 1.4328; K = 6; N' = 102; R =
333.333 f.sub.s = 1.3455; f.sub.EC50 = 1.4593; f.sub.EC99 = 2.2105
EC.sub.50: mean value = 10.5116 (95% confidence limits: lower
7.2030; upper 15.3400) EC.sub.99: mean value = 264.0564 (95%
confidence limits: lower 119.4579; upper 583.6850)
[0133] Compound 5a shows marked activity against malaria and is
about four times as effective as benflumetol. In addition, the
sensitivity of Plasmodium falciparum to compound 5a has a steeper
incremental function (S) than benflumetol.
Example 6.3
Comparison of the Efficacy of Benflumetol and
2-n-pentylamino-1-[2,7-dichl-
oro-9-(4-chlorobenzylidene)-9H-fluoren-4-yl]ethanol (5c):
[0134] The response parameters for benflumetol are defined in Table
5 (see above) and those for compound 5c in Table 7. The .chi..sup.2
for heterogeneity shows an acceptable agreement between the data
observed and the regression lines.
[0135] Not one of the isolates shows schizont maturation at a
concentration of 3000 nmol/l 5c, and the great majority of isolates
(95%) are completely inhibited even at 100 nml/l 5c.
[0136] There are major differences in the sensitivity of the
isolates to either benflumetol or compound 5c. For example, the
EC.sub.99 (99% inhibition versus controls not given active
substance), which is the most important indicator for clinical
efficacy of compound 5c (105.04 nmol/l) in non-immune persons, is
about 4 (four) times lower than that for benflumetol (422.49
nmol/l), i.e. the same effect on Plasmodium falciparum is attained
with substance 5c with a dose about 75% lower than that used with
benflumetol.
[0137] Statistical comparison according to Litchfield &
Wilcoxon shows that the regression lines run parallel within the
limits of experimental error because the slope ratio (SR=1.3277) is
smaller than the factor of the slope ratio (f.sub.SR=1.5017). Since
the "power ratio" (PR= 2.0724) is also greater than the factor of
the power ratio (f.sub.PR=1.7033), the difference in efficacy
between benflumetol and compound 5c is statistically
significant.
[0138] The 34 EC.sub.50 pairs are tested for correlation. With a
correlation coefficient of 0.6044, the result is significant. This
applies also to the 34 EC.sub.90 pairs with a correlation
coefficient of 0.8796.
7TABLE 7 Concentration-dependent inhibitory effect of
2-pentylamino-1- [2,7-dichloro-9-(4-chlorobenzylidene)-9H-fluor-
en-4-yl)]ethanol (5c) on Plasmodium falciparum in vitro: Active
substance Inhibition of concentration (nmol/l) schizont maturation
in % 3.0 6.83 10.0 36.40 30.0 81.18 100.0 94.78 300.0 96.96 1000.0
99.61 3000.0 100.00 n = 34; a = 3.0184; b = 0.7436; r = 0.9696;
.chi..sup.2 = 4.7652 S = 3.8093; A = 1.3296; K = 6; N' = 68; R =
1000 f.sub.s = 1.3446; f.sub.EC50 = 1.5672; f.sub.EC99 = 2.2892
EC.sub.50: mean value = 14.3678 (95% confidence limits: lower
9.1681; upper 22.5167) EC.sub.99: mean value = 328.1566 (95%
confidence limits: lower 143.3474; upper 751.2290)
[0139] Compound 5c shows activity per se against malaria and is
about five times as effective as benflumetol.
[0140] It is shown that exchanging the dibutylamino group in
benflumetol for a monoalkylamino group results in benflumetol
derivatives which show an activity that appears to be markedly
superior.
Example 7
Tablets
[0141] The active substance desbutyl benflumetol is passed through
a (60 mesh) sieve and, after mixing, compressed to form tablets of
the following composition:
8 Desbutyl benflumetol 120 mg Microcrystalline cellulose 100 mg
Corn starch 160 mg Sodium carboxymethyl starch 12 mg Highly
dispersed silica 3 mg Magnesium stearate 5 mg Total 400 mg
* * * * *