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Description  |
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BACKGROUND OF THE INVENTION
The present invention is concerned with certain diamidines and a
bis-imidazoline having antiprotozoal activity, and their use in the
control of trypanosomiasis and/or babesiosis in mammals, particularly in
cattle.
Trypanosomiasis is a disease of man and animals caused by flagellate blood
borne protozoan parasites. The disease is encountered mainly in Africa,
where it is transmitted by the Tse Tse fly. Animal typanosomiasis caused
by Trypanosoma congolense and T. vivax, is considered to be the limiting
factor for livestock production in most of the African Continent. Although
trypanosomiasis can be fatal to man, its devastating effect on meat
producing animals has indirectly caused much more human suffering due to
protein starvation. Babesiosis is another hemo-protozoan disease of
livestock and is economically important in the tropical and subtropical
regions of the world.
Previously reported diamidines having antiprotozoal activity include
##STR2##
wherein Z is: --NH--N.dbd.N-- (diminazene, see The Merck Index, 9th Ed.,
monograph No. 3258);
--CH.dbd.CH-- (stilbamidine, loc. cit., monograph No. 8597; Ashley et al.
[A], J. Chem. Soc., pp. 103-116, 1942);
--CH.dbd.CH--CH.dbd.CH-- (Ashley et al. [A]);
--O(CH.sub.2).sub.p O--, where p=1 to 10 (Ashley et al. [A]; when p=5,
pentamidine, loc. cit., monograph No. 6912); or
--O-- (phenamidine, loc. cit., monograph No. 6994); and
##STR3##
wherein Y is O, S, NH, NCH.sub.3 or CH.sub.2 (Dann et al. [A], Ann. vol.
749, pp. 68-89, 1971; Dann, U.S. Pat. Nos. 3,652,591 and 3,689,506).
On the other hand, compounds failing to protect (cure) mice against a
protozoal infection include those compounds of the formula (I) wherein Z
is --CO--, --CHOH--, --CH.sub.2 CO--, --CH.dbd.CHCO--, --NHCO--,
--SO.sub.2 --, --NHSO.sub.2 --, --S--S--, --N.dbd.N--, --NHNH--,
--N.dbd.N(O)--, --CH.sub.2 --, --S--, --CH.sub.2 NH--, --NHCONH--,
--OCH.sub.2 OCH.sub.2 O--, --CH.sub.2 SCH.sub.2 --, --CH.sub.2 NHCH.sub.2
--, --OCH.sub.2 (p--C.sub.6 H.sub.4)CH.sub.2 O-- or --CH.sub.2 O
(p--C.sub.6 H.sub.4)OCH.sub.2 --; in spite of the fact that the compounds
having the last seven values of Z did show an early and favorable effect
on the level of trypanosomes in the peripheral blood stream (Ashley et al.
[A]; Ashley et al. [B], J. Chem. Soc., pp. 3089-3093, 1957). Furthermore,
replacement of --O(CH.sub.2).sub.4 O-- in (I) with an olefinic variant,
--OCH.sub.2 CH.dbd.CHCH.sub.2 O--, leads to considerable less activity
against T. rhodesiense and inactivity against T. congolense (Ashley et al.
[C], J. Chem. Soc., pp. 1668-1671, 1957); substitution of the bridging
group in diminazene with a methyl group, i.e.,
Z.dbd.--N(CH.sub.3)N.dbd.N--, reduces activity by about 75% (Ashley et al.
[B]); and the m, m'-isomers of the compounds (I) wherein Z is
--O(CH.sub.2).sub.3 O-- or --O(CH.sub.2).sub.5 O-- are about half as
active as the p, p'-isomers.
Among the diamidines reported to have antiprotozoal activity are a number
of compounds having the formula (I) wherein Z is represented by one of the
following 5-membered heterocyclic groups:
##STR4##
where Q is O, S, NH or N(CH.sub.3);
##STR5##
where Q' is S, NH or CH.sub.2 ;
##STR6##
(Das et al. [A], J. Med. Chem. Vol. 20, pp. 531-536, 1977; Das et al. [B],
ibid., Vol. 20, pp. 1219-1221, 1977; Das et al. [C, ibid., Vol. 23, pp.
578-581, 1980; Dann et al. [B], Ann. pp. 160-194, 1975). For a similar
compound (I), wherein Z is
##STR7##
reports concerning activity are conflicting. Thus, against T. rhodesiense
infections in mice, Das et al. [C] reports no more than a minor increase
in mean survival time, at a dose of 40 mg/kg; while earlier Dann et al.
[B] reported minimum curative dose of 1-10 mg/kg for the same compound
against the same microorganism.
It has also been previously noted by Berg (J. Chem. Soc., pp. 5097-5101,
1961) that the compound of the formula (I) wherein Z is --NHCONH-- is
lacking in activity, although the corresponding meta isomer:
##STR8##
showed considerable activity. Berg further noted that replacement of the
--NHCONH-- group in (III) with --NHC(.dbd.NH)NH--,
--NHC(.dbd.NCH.sub.3)NH-- or --NHCSNH-- led to lowered activity.
The bis-imidazoline compound of the formula
##STR9##
presently discovered to have antiprotozoal activity, has been previously
reported to have antifungal activity (Anne et al., Antimicrobial Agents
and Chemotherapy, vol. 18, pp. 231-239, 1980), and to inhibit oncornaviral
DNA polymerase (De Clercq et al., J. Med. Chem., Vol. 23, pp. 787-795,
1980). Neither Anne et al. nor DeClercq et al. describe compound (IV) per
se, nor do they provide a method of preparation therefor. For this reason,
a detailed preparation method for this compound is included below.
SUMMARY OF THE INVENTION
The present invention encompasses compounds of the formula
##STR10##
wherein X is --CH.sub.2 CH.dbd.CH--, --CH.sub.2 C(CH.sub.3).dbd.CH--,
##STR11##
n is 0, 1 or 2; m is 0 or 1;
R is (C.sub.1 -C.sub.3)alkyl, 2-hydroxyethyl, 2,3-dihydroxypropyl, benzyl
or 2-, 3- or 4-picolyl; with the provisos that when R is 4-picolyl, m is
1; and when R is methyl and m is 1, n is other than O;
and the pharmaceutically-acceptable acid addition salts thereof. Such salts
include, but are not limited to, those formed with HCl, H.sub.2 SO.sub.4,
H.sub.3 PO.sub.4, propionic acid, succinic acid, maleic acid, citric acid,
methanesulfonic acid, isethionic acid, p-toluenesulfonic acid and aceturic
acid. The preferred salts, because of their more consistent biological
activity, are those with HCl.
It is clear from the above background of the invention that the present art
is highly unpredictable in character. Present studies have further proven
that view to be correct, in that we are now able to extensively add to the
list of compounds of the formula (I) which are lacking in antiprotozoal
activity. For example, those compounds wherein Z is
--C(CH.sub.3).dbd.CHCH.sub.2 --, --CH.dbd.C (C.sub.6 H.sub.5)CH.sub.2 --,
--CH.dbd.C(CO.sub.2 CH.sub.3)CH.sub.2 --, --N.dbd.C(NHCH.sub.3)NH-- or
##STR12##
where R.sup.a is --CH.sub.2 CH.dbd.CH.sub.2 or CH.sub.3, when tested in
mice against T. congolense or B. rodhaini by the method detailed below,
show no activity against either microorganism at a dose of 50 mg/kg. In
spite of these facts, it has now been discovered that the compounds of the
formula (V) possess valuable antiprotozoal activity, in particular, in
vivo activity against Trypanosome congolense and/or Babesia rodhaini, as
determined in laboratory induced infections in mice, reflecting general
utility in the treatment of trypanosomiasis and/or babesiosis in mammals,
particularly in cattle. The activity of the present p-substituted
compounds is particularly surprising in view of the teaching of Berg
(cited above) and the further fact that m-isomers of the present compounds
show no useful activity against either of the above microorganisms (vide
post).
The present invention also encompasses a pharmaceutical composition for use
in the treatment of a susceptible protozoan infection in a mammal,
comprising an antiprotozoal compound of the formula (V) and a
pharmaceutically inert carrier; and a method of treating an infection in a
mammal caused by a susceptible protozoan, which comprises administering an
antiprotozoal amount of a compound of the formula (V).
The present invention further encompasses that same treatment method, but
with the compound of the formula (IV), above, or a
pharmaceutically-acceptable salt thereof; and a sterile pharmaceutical
composition suitable for parenteral administration to a mammal which is
infected with a susceptible protozoan, said composition comprising an
antiprotozoal effective amount of a compound of the formula (IV), at a
concentration of at least 1% (w/v), and a pharmaceutically inert carrier.
DETAILED DESCRIPTION OF THE INVENTION
The bis-amidine compounds (V) of the present invention are readily prepared
from a corresponding dinitrile of the formula
##STR13##
wherein X is as defined above; via an intermediate dicarboximidate ester
of the formula
##STR14##
wherein X is as defined above and R is (C.sub.1 -C.sub.5)alkyl or (C.sub.2
-C.sub.5)alkoxyalkyl. Preferred values of R are methyl, ethyl and
2-methoxyethyl.
The first stage, (VI).fwdarw.(VII), is carried out by reacting the
dinitrile (VI) with at least 2 equivalents of an alcohol (ROH, where R is
as defined above) in the presence of at least 2 equivalents of a strong,
anhydrous acid (e.g., HCl, H.sub.2 SO.sub.4 or sulfonic acid such as
methanesulfonic acid, isethionic acid or p-toluenesulfonic acid), under
anhydrous conditions in a reaction-inert solvent, conveniently in an
excess of the alcohol, ROH, optionally diluted with a further
reaction-inert solvent such as chloroform. Preferred alcohols (methanol,
ethanol, 2-methoxyethanol) correspond to the preferred groups R, as
specified above. Temperature is not critical, the range -20.degree. to
50.degree. C. being fully satisfactory. Ambient temperature is preferred,
avoiding costs associated with cooling or heating. The preferred acid is
dry HCl conveniently introduced in excess by perfusing the alcoholic
solvent at -20.degree. to 0.degree. C. prior to reaction with the
dinitrile. The intermediate dicarboximidate ester (VII) is readily
isolated from the reaction mixture, usually in the form of an addition
salt with the acid used in the process. Said isolation is accomplished by
standard methods of concentration, and/or addition of a non-solvent or of
a further excess of the acid, as necessary to obtain a recoverable solid.
As used herein, the expression "reaction-inert solvent" refers to any
solvent which does not react with reactants, intermediates or product in a
manner which adversely affects the yield of the desired product.
The second stage, (VII).fwdarw.(V), is carried out by reacting the
dicarboximidate ester (VII), usually in the form of an acid addition salt,
with excess ammonia (at least four equivalents, to form the bis-amidine,
plus at least one equivalent for each equivalent of acid associated with
the addition salt). Temperature is not critical; again, the range
0.degree.-50.degree. C. being fully satisfactory, with ambient
temperatures preferred. The reaction is usually carried out in anhydrous
reaction-inert solvent, alcohols such as those used in the above first
stage being particularly well-suited. In this case, it will be noted that
the alcohol need not correspond to the value of R in the starting
material, since even although a different alcohol may interact with the
starting material (by ester exchange), there will be no adverse effect on
yield. The diamidine product (V) is isolated, most conveniently in the
form of the same acid addition salt as that introduced into the present
stage, by the same standard methods detailed above for the isolation of
intermediate ester (VII). If an alternative salt of (V) is desired, it is
preferable to first convert the isolated salt to the free base form, a
conversion which is conveniently done by neutralization of the acid
addition salt in water, with recovery of free base by filtration or
extraction into a water immiscible solvent. The free base is then
contacted with the appropriate acid in a reaction-inert solvent. Those
salts which do not precipitate directly are isolated by concentration
and/or by addition of a non-solvent.
When the final product contains an optional sulfone or sulfoxide group and
that group is not already present in the starting dinitrile, it can be
introduced by the oxidation of a corresponding thioether derivative. An
oxidizing agent particularly well-suited to the present purpose is 30%
H.sub.2 O.sub.2, with substantially 1 equivalent used to form the
sulfoxide and at least 2 equivalents used to form the sulfone. Either
oxidation is generally carried out in the presence of a reaction-inert
solvent (e.g., methanol). Temperature is not critical, the range
0.degree.-50.degree. C. being fully satisfactory; ambient temperatures are
preferred.
The dinitriles (VI) required as starting materials for synthesis of the
present diamidine compounds are readily prepared from known compounds
(available commercially or prepared according to literature methods).
Preparations 1-50 detailed below provide extensive exemplification of
methods for the preparation of said dinitriles.
The utility of the compounds (IV) and (V) in the treatment of
trypanosomiasis and/or babesiosis is demonstrated by their in vivo
activity against Trypanosome congolense and Babesia rodhaini infections in
mice. Groups of mice (usually 10 in number) are infected, usually
intraperitoneally, with a multiple of the 100% lethal dose of the
microorganism. The ability of a given subcutaneous dose of the test
compound to prevent death over a 4 week period is then determined.
Activity is expressed as % protection, i.e., the proportion of the group
of lethally infected mice which survive at the given dosage. Because they
show at least 80% protection at a subcutaneous dose of 50 mg/kg, against
both Trypanosome congolense and Babesia rodhaini, most highly preferred
compounds of the formula (V) are those wherein X is --CH.sub.2
CH.dbd.CH.sub.2,
##STR15##
Additional preferred compounds, because they show at least 90% protection
against Trypanosome congolense at a dose no higher than 50 mg/kg, are the
three compounds of the formula (V) wherein X is --NHC(.dbd.NH)NH--, or
##STR16##
with R as 4-picolyl; although it is further noted that these two
compounds,
##STR17##
show 0% protection against Babesia rodhaini. Further preferred compounds,
because they show at least 90% protection against Babesia rodhaini at a
dose no higher than 50 mg/kg, are the four compounds of the formula (V)
wherein X is --CH.sub.2 C(CH.sub.3).dbd.CH--,
##STR18##
Of the latter compounds, the third is more preferred, also showing 40%
protection against Trypanosome congolense at 50 mg/kg. It is further noted
that the first of these four compounds shows 10% protection against
Trypanosome congolense at 50 mg/kg, while the second and fourth (like
compounds of the formula (V) wherein X is
##STR19##
where R is 2-picolyl or 3-picolyl) show 0% protection against Trypanosome
congolense at 50 mg/kg. The compound of the formula (IV) is also a
preferred compound, in that it shows 100% protection against Babesia
rodhaini at a dose of 6.25 mg/kg (although it shows 0% protection against
Trypanosome congolense even at 100 mg/kg.)
By way of contrast, known 1,3-di(m-amidinophenyl)guanidine of Berg (cited
above) showed no activity against Trypanosome congolense or Babesia
rodhaini (at 50 mg/kg or 25 mg/kg, respectively); and the further
m-disubstituted amidine, 1,3-di(m-amidinophenyl)propene (isomeric with one
of the present most highly preferred compounds) showed no activity against
Trypanosome congolense at 50 mg/kg, and although showing 33% protection
against Babesia rodhaini at 25 mg/kg, was toxic at this dose.
In treating natural infections in mammals due to a susceptible protozoan,
the mammal is dosed, preferable parenterally (e.g., subcutaneously,
intramuscularly or intraperitoneally) with 1-100 mg of the active compound
(in single or divided doses) per kilogram of body weight of the mammal.
The compounds of the formulae (IV) and (V) are formulated in sterile form
for parenteral administration (injection) according to methods well known
in the pharmaceutical art, employing such standard excipients, buffers,
solvents, suspending agents and preservatives as are commonly employed for
such parenteral dosage forms. These formulations can be solutions or
suspensions; in preconstituted liquid form, or as dry powders for
reconstitution shortly before injection. The concentration of drug in
vehicle will generally be relatively high (e.g., 5-20%), certainly at
least 1% w/v, in order to minimize the volume of injection.
The present invention is illustrated by the following examples. However, it
should be understood that the invention is not limited to the specific
details of these examples. Unless otherwise specified, all operations were
carried out at ambient temperature; all temperatures are in degrees
centigrade; stripping of all solvents was carried out at reduced pressure;
all tlc (thin layer chromatography) was carried out on commercial silica
gel plates containing an ultra violet sensitive detector, with the eluant
specified in parentheses; all solution drying was over MgSO.sub.4 ; and
all solvent ratios are by volume. The abbreviations DMF, THF and DMSO
refer, respectively, to dimethylformamide, tetrahydrofuran and
dimethylsulfoxide.
EXAMPLE 1
Diethyl p,p'-(1,3-Diphenylpropene)dicarboximidate Dihydrochloride
1,3-Di(p-cyanophenyl)propene (11.9 g, 0.049 mole) was taken into 640 ml
15:1 CHCl.sub.3 :absolute ethanol, cooled to -10.degree. to 0.degree. and
perfused with HCl gas for 65 minutes, then allowed to stand at room
temperature for 40 hours and finally stripped to yield title product as a
white solid; 15.5 g; ir(KBr) 3.45, 6.25, 6.90, 7.25, 7.35 and 9.25
microns.
EXAMPLE 2
1,3-Di(p-amidinophenyl)propene Dihydrochloride
Absolute ethanol (350 ml) was saturated with NH.sub.3 at
0.degree.-5.degree. by perfusing with NH.sub.3 gas for 25 minutes. Title
product of the preceding Example (15.5 g, 0.038 mole) was added, the
mixture was allowed to warm to room temperature and stirred for 4 days.
Crystallization was induced by cooling to 0.degree.-5.degree. C. for 2
hours. After granulating for 1 day at room temperature, title product was
recovered by filtration with acetone wash: 7.2 g; m.p.
314.degree.-318.degree.; tlc (2:1:1 butanol:H.sub.2 O:CH.sub.3 CO.sub.2 H)
Rf 0.34.
Analysis: Calculated: C, 55.34; H, 6.02; N, 15.18; Cl.sup.-, 19.21. Found:
C, 55.10; H, 5.98; N, 15.21; Cl.sup.-, 19.06.
To obtain a second crop, the filtrate was stripped to a yellow foam which
was triturated with acetone, stirred with 50 ml 2N HCl (initially added
dropwise) and filtered with acetone wash: 3.3 g; m.p.
314.degree.-318.degree..
EXAMPLE 3
Diethyl p,p'-(2-Methyl-1,3-diphenylpropene)dicarboximidate Dihydrochloride
1,3-Di(p-cyanophenyl)-2-methylpropene (800 mg) was converted to title
product by the method of Example 1. After stripping, the resulting foam
was triturated with acetone: 1.2 g; ir(KBr) 3.0, 3.40, 6.25, 6.95, 7.25,
7.45 and 9.45 microns.
EXAMPLE 4
2-Methyl-1,3-di(p-amidinophenyl)propene Dihydrochloride
Title product of the preceding Example (1.2 g) was converted to present
title product by the method of Example 2. After 4 days at room
temperature, the reaction mixture was stripped to yield title product as
an oil which solidified on trituration with acetone: 766 mg; tlc (2:1:1
butanol:H.sub.2 O:CH.sub.3 CO.sub.2 H) Rf 0.6; ir(KBr) 3.05, 3.25, 6.06,
6.25, 6.50 and 6.75 microns.
EXAMPLE 5
Di(2-methoxyethyl) p,p'-(1,3-Diphenylguanidine)dicarboximidate
Dihydrochloride
2-Methoxyethanol (35 ml) was cooled in an acetone-ice bath and purged with
dry HCl for 20 minutes. 1,3-Di(p-cyanophenyl)guanidine (500 mg) was added
and the mixture warmed to room temperature and stirred 20 hours. The
reaction mixture was stripped of excess HCl, poured into 300 ml ether,
granulated and title product recovered by filtration; ir(KBr) 2.92, 3.48,
6.00, 6.21, 6.95, 8.00, 8.32, 8.80 and 9.10 microns. The entire product
was used in the next step.
EXAMPLE 6
1,3-Di(p-amidinophenyl)guanidine Dihydrochloride
The entire title product from the preceding Example was taken into absolute
ethanol (50 ml), cooled to 0.degree.-5.degree. C., and the solution purged
with NH.sub.3 for 15 minutes. After stirring for 60 hours at room
temperature, the reaction mixture was stripped to solids, which were
slurried in 5 ml methanol and cooled to 0.degree.-5.degree. C. The cold
slurry was purged with dry HCl, initially forming a solution from which
title product crystallized: 595 mg; m.p. 325.degree.-330.degree.; ms 261,
244, 236; high resolution ms 278, 261, 244 (no oxygen); tlc (2:1:1
butanol:H.sub.2 O:CH.sub.3 CO.sub.2 H) Rf 0.05.
EXAMPLE 7
Di(2-methoxyethyl) p,p,'-(1,3-Diphenylpyrrole)dicarboximidate
Dihydrochloride
By the method of Example 5, 1,3-di(p-cyanophenyl)pyrrole (600 mg) was
converted to present title product: 974 mg; ir(KBr) 3.00, 3.45, 5.90,
6.25, 6.90, 7.40, 7.85, 8.35 and 9.45.
EXAMPLE 8
1,3-Di(p-amidinophenyl)pyrrole Dihydrochloride
Title product of the preceding Example (974 mg) was converted to present
title product by the method of Example 2, it being unnecessary to cool the
reaction mixture to induce precipitation of the product. At the end of the
reaction period, the reaction mixture was filtrated and the filtrate
reserved. The filter cake was repulped for 10 minutes in 8 ml 2N HCl and
refiltered with acetone wash to yield a first crop of title product: 200
mg; ms 303, 286, 269; ir(KBr) shows amidine band at 6.00 microns; tlc
(2:1:1 butanol:H.sub.2 O:CH.sub.3 CO.sub.2 H) Rf 0.27.
Analysis: Calculated: C, 54.84; H, 5.38; N, 17.76; Cl.sup.- 17.98. Found:
C, 55.24; H, 5.62; N, 17.44; Cl.sup.- 16.71.
A second crop was obtained by stripping the reserved filtrate to solids
which were then further processed as above: 160 mg.
EXAMPLE 9
Di(2-methoxyethyl) p,p'-(1,4-Diphenylimidazole)dicarboximidate
Dihydrochloride
By the method of Example 5, 1,4-di(p-cyanophenyl)imidazole (436 mg) was
converted to present title product: 721 mg; ir(KBr) 3.00, 3.50, 6.10-6.25,
6.90, 7.15, 7.85, 8.70, 8.85, 9.20 and 9.35 microns.
EXAMPLE 10
1,4-Di(p-amidinophenyl)imidazole Dihydrochloride
By the method of Example 8, title product of the preceding Example (721 mg)
was converted to present title product. The crude product which was
isolated directly from the reaction mixture (330 mg) was slurried in 30 ml
ethanol, purged with dry HCl, cooled and refiltered to yield purified
title product: 239 mg; m.p. 359.degree.361.degree. (dec.); tlc (2:1:1
butanol:H.sub.2 O:CH.sub.3 CO.sub.2 H) Rf 0.26.
A second crop (75 mg) was obtained by concentration of the ethanol mother
liquor.
EXAMPLE 11
Di(2-methoxyethyl) p,p'-(2,5-Diphenyltetrazole)dicarboxidate
Dihydrochloride
By the method of Example 5, 2,5-di(p-cyanophenyl)tetrazole (400 mg) was
converted to present title product: 666 mg (91%); ir(KBr) 2.90, 3.45,
6.10, 6.85, 7.15, 7.90, 8.50, 8.90, 9.30 and 9.85 (doublet) microns.
EXAMPLE 12
2,5-Di(p-amidinophenyl)tetrazole Dihydrochloride
By the method of Example 8, title product of the preceding Example (660 mg)
was converted to present title product. The crude product isolated
directly from the reaction mixture was repulped sequentially in ethyl
acetate, 2N HCl and acetone to yield purified title product: 284 mg; tlc
(2:1:1 butanol:H.sub.2 O:CH.sub.3 CO.sub.2 H) Rf 0.14; ms 261, 244, 116.
EXAMPLE 13
Di(2-methoxyethyl) p,p'-(1,4-Diphenyl-2-methylimidazole)dicarboximidate
Dihydrochloride
By the method of Example 5, 1,4-di(p-cyanophenyl)-2-methylimidazole (350
mg, 0.0012 mole) was converted to present title product: 611 mg; ir(KBr)
2.82, 3.42, 6.10, 6.20, 6.95, 7.38 and 9.00 microns.
EXAMPLE 14
1,4-Di(p-amidinophenyl)-2-methylimidazole Dihydrochloride
By the method of Example 4, title product of the preceding Example (611 mg)
was converted to present title product. The reaction mixture, which was
clarified prior to stripping, gave crude product as a yellow foam. The
latter was triturated with acetone and then a combination of acetone and
2N HCl, and finally filtered with acetone wash to yield title product: 378
mg; pnmr/DMSO-d.sub.6 /delta 2.85 (s, 3H, CH.sub.3), 8.0-8.65 (m, 9H,
aromatic), 9.45-10.1 (bd. t, 8H, protonated amidine groups)ppm.
EXAMPLE 15
Di(2-methoxyethyl) p,p'-(1,4-diphenyl-2-benzylimidazole)dicarboximidate
Dihydrochloride
By the method of Example 5, 1,4-di(p-cyanophenyl)-2-benzylimidazole (240
mg) was converted to present title product: 370 mg; ir(KBr) 2.94, 3.40,
6.05, 6.15 and 7.35 microns.
EXAMPLE 16
1,4-Di(p-amidinophenyl)-2-benzylimidazole Dihydrochloride
By the method of Example 14, title product of the preceding Example (370
mg) was converted to present title product: 225 mg; ir(KBr) no CN band,
C.dbd.N band at 6.00 microns; tlc (2:1:1 butanol:H.sub.2 O:CH.sub.3
CO.sub.2 H) Rf 0.39. Title product (195 mg) was further purified by
dissolving in 15 ml methanol, briefly purging with dry HCl, stripping,
triturating with cold 2N HCl, and filtering with 2N HCl and finally
acetone wash: 116 mg.
EXAMPLE 17
Di(2-methoxyethyl) p,p'[1,4-Diphenyl-2-(2-picolyl)imidazole]dicarboximidate
Trihydrochloride
By the method of Example 5, 1,4-di(p-cyanophenyl)-2-(2-picolyl)imidazole
hydrochloride (580 mg) was converted to present title product: 930 mg;
ir(KBr) 2.90, 3.44, 6.20, 6.85, 7.15, 7.35 and 8.32 microns.
EXAMPLE 18
1,4-Di(p-amidinophenyl)-2-(2-picolyl)imidazole Trihydrochloride
By the procedure of Example 4, title product of the preceding Example (925
mg) was converted to present title product. The initially isolated, crude
oil was combined with acetone, diluted dropwise with 2N HCl and then with
methanol. Since oily material remained, the whole was restripped, the
residue was treated with 5 ml CH.sub.3 OH, and solids (160 mg) recovered
by filtration. The filtrate was purged with HCl gas for 2 minutes and then
diluted with 50 ml acetone to precipitate title product, which was
recovered by filtration with acetone wash: 393 mg; m.p. 215.degree.
(dec.); ir(KBr) no CN band, includes C.dbd.N band at 6.00 microns; tlc
(2:1:1 butanol:H.sub.2 O:CH.sub.3 CO.sub.2 H) Rf 0.10.
EXAMPLE 19
Di(2-methoxyethyl) p,p'(1,4-Diphenyl-2-methylthioimidazole)dicarboximidate
Dihydrochloride
By the method of Example 5, 1,4-di(p-cyanophenyl)-2-methylthioimidazole
(340 mg) was converted to present title product: 456 mg; ir(KBr) 2.91,
3.44, 6.20, 6.85, 7.15, 7.35 and 8.32 microns.
EXAMPLE 20
1,4-Di(p-amidinophenyl)-2-methylthioimidazole Dihydrochloride
By the procedure of Example 4, title product of the preceding Example (456
mg) was converted to present title product. Following trituration with
acetone, the product was further triturated with a mixture of acetone and
2N HCl and recovered by filtration with acetone wash: 248 mg;
pnmr(CDCl.sub.3) includes singlet at 2.7 ppm (SCH.sub.3); ir(KBr) no CN
band, includes C.dbd.N band at 6.00 microns; ms includes 333 (m-17) and
316 (m-34); tlc (2:1:1 butanol:H.sub.2 O:CH.sub.3 CO.sub.2 H) Rf 0.25.
EXAMPLE 21
1,4-Di(p-amidinophenyl)-2-methanesulfonylimidazole Dihydrochloride
Title product of the preceding Example (225 mg) was dissolved in 10 ml
CH.sub.3 OH and cooled to 0.degree.-5.degree. C. Excess 30% H.sub.2
O.sub.2 (50 drops, greater than 2 equivalents) was added and the mixture
warmed to room temperature, stirred 60 hours, and finally stripped to an
oil which was solidified by trituration with methanol to yield title
product: 221 mg; tlc (2:1:1 butanol:H.sub.2 O:CH.sub.3 CO.sub.2 H) Rf
0.15.
By restricting the amount of H.sub.2 O.sub.2 to 1 equivalent, the
corresponding sulfoxide,
1,4-di(p-amidinophenyl)-2-methanesulfinylimidazole dihydrochloride, is
obtained.
EXAMPLE 22
Di(2-methoxyethyl) p,p'-(1,4-Diphenyl-2-propylthioimidazole)dicarboximidate
Dihydrochloride
By the method of Example 5, 1,4-di(p-cyanophenyl)-2-propylthioimidazole
(500 mg) was converted to present title product; ir(KBr) 2.95, 3.40, 6.20,
6.80, 7.30, 8.80 and 9.10 microns. The entire batch of product was used in
the next step.
EXAMPLE 23
1,4-Di(p-amidinophenyl-2-propylthioimidazole Dihydrochloride
By the method of Example 4, title product of the preceding Example (entire
batch) was converted to present title product. Prior to stripping, the
reaction mixture was treated with activated carbon. The crude residue,
after stripping, was taken up in 5 ml CH.sub.3 OH, the solution purged for
10 minutes with dry HCl, and title product precipitated by dilution with
acetone: 381 mg; ms 362, 345, 302, 232, 219; tlc (2:1:1 butanol:H.sub.2
O:CH.sub.3 CO.sub.2 H) Rf 0.50.
EXAMPLE 24
Di(2-methoxyethyl)
p,p'-[1,4-Diphenyl-2-(2-hydroxyethylthio)imidazole]dicarboximidate
Dihydrochloride
By the method of Example 5,
1,4-di(p-cyanophenyl)-2-(2-hydroxyethylthio)imidazole (500 mg) was
converted to present title product: 817 mg; ir(KBr) 2.90, 3.40, 6.25, 6.95
and 9.35.
EXAMPLE 25
1,4-Di(p-amidinophenyl)-2-(2-hydroxyethylthio)imidazole Dihydrochloride
By the method of Example 6, title product of the preceding Example (817 mg)
was converted to present title product, which was precipitated from the
methanol/HCl by dilution with acetone: 377 mg; m.p. >250.degree.; tlc
(2:1:1 butanol:H.sub.2 O:CH.sub.3 CO.sub.2 H) Rf 0.42.
EXAMPLE 26
Di(2-methoxyethyl)
p,p'-[1,4-Diphenyl-2-(2,3-dihydroxypropylthio)imidazole]dicarboximidate
Dihydrochloride
By the method of Example 5,
1,4-di(p-cyanophenyl)-2-(2,3-dihydroxypropylthio)imidazole (331 mg) was
converted to present title product; ir(KBr) 2.90, 3.40, 6.25, 6.85, 7.35
and 9.00. The entire batch was used in the next step.
EXAMPLE 27
1,4-Di(p-amidinophenyl)-2-(2,3-dihydroxypropylthio)imidazole
Trihydrochloride
By the procedure of Example 6, title product of the preceding Example (the
entire batch) was converted to present title product: 296 mg; ms 267, 252,
209; tlc (2:1:1 butanol:H.sub.2 O:CH.sub.3 CO.sub.2 H) Rf 0.25.
EXAMPLE 28
Di(2-methoxyethyl)
p,p'-[1,4-Diphenyl-2-(3-picolylthio)imidazole]dicarboximidate
Trihydrochloride
By the procedure of Example 5,
1,4-Di(p-cyanophenyl)-2-(3-picolylthio)imidazole (0.48 g) was converted to
present title product: 0.78 g, ir(KBr) 2.90, 3.40, 6.25, 6.95, 7.45 and
9.10.
EXAMPLE 29
1,4-Di(p-amidinophenyl)-2-(3-picolylthio)imidazole Trihydrochloride
By the method of Example 4, title product of the preceding Example (0.78 g)
was converted to present title product. The initially formed oil was taken
up in 2 ml of 2N HCl and crystallized by slowly adding 10 ml of acetone to
the stirred solution: 0.37 g; ms 393 (m-2NH.sub.3); ir(KBr) no CN band,
C.dbd.N band at 6.00 microns; tlc (2:1:1 butanol:H.sub.2 O:CH.sub.3
CO.sub.2 H) Rf 0.14.
EXAMPLE 30
Di-(2-methoxyethyl)
p,p'[1,4-Diphenyl-2-(4-picolylthio)imidazole]dicarboximidate
Trihydrochloride
By the method of Example 5,
1,4-di(p-cyanophenyl)-2-(4-picolylthio)imidazole (500 mg) was converted to
present title product, ir(KBr) 2.95, 3.40, 6.30, 6.70, 6.95 and 7.90
microns. The entire batch of product was used in the next step.
EXAMPLE 31
1,4-Di(p-amidinophenyl)-2-(4-picolylthio)imidazole Trihydrochloride
By the method of Example 6, the entire batch of title product from the
preceding Example was converted to present title product: 500 mg; m.p.
230.degree.-240.degree.; ms 395, 301, 243; tlc (2:1:1 butanol:H.sub.2
O:CH.sub.3 CO.sub.2 H) Rf 0.08. A second crop (128 mg) was obtained from
mother liquor by addition of acetone.
EXAMPLE 32
Di-(2-methoxyethyl
p,p'[1,4-Diphenyl-2-(2-picolylthio)-imidazole]dicarboximidate
Trihydrochloride
By the method of Example 5,
1,4-di(p-cyanophenyl)-2-(2-picolylthio)imidazole (500 mg) was converted to
present title product; ir(KBr) 2.90, 3.40, 6.30, 6.85, 7.15, 7.35 and 9.20
microns. The entire batch of product was used in the next step.
EXAMPLE 33
1,4-Di(p-amidinophenyl)-2-(2-picolylthio)imidazole Trihydrochloride
By the procedure of Example 25, the entire batch of title product of the
preceding Example was converted to present title product: 729 mg; ms 393,
360, 259, 243; tlc (2:1:1 butanol:H.sub.2 O:CH.sub.3 CO.sub.2 H) Rf 0.17.
EXAMPLE 34
Di(2-methoxyethyl) p,p'-(1,4-Diphenyl-2-benzylthioimidazole Dihydrochloride
By the method of Example 5, 1,4-di(p-cyanophenyl)-2-(benzylthio)imidazole
was converted to present title product: 300 mg; ir(KBr) 2.90, 3.40, 6.30,
6.85, 7.35 and 7.80 microns.
EXAMPLE 35
1,4-Di(p-amidinophenyl)-2-(benzylthio)imidazole Dihydrochloride
By the method of Example 6, title product of the preceding Example (300 mg)
was converted to present title product. Since the initially formed oil did
not crystallize from the cold CH.sub.3 OH-HCl solution, it was restripped
and the residue crystallized by trituration with a mixture of 2N HCl and
ethyl acetate: 163 mg; tlc (2:1:1 butanol:H.sub.2 O:CH.sub.3 CO.sub.2 H)
Rf 0.50.
EXAMPLE 36
2-[4-(2-Imidazolidinyl)phenyl]-6-(2-imidazolidinyl)indole Dihydrochloride
2-(p-Cyanophenyl)-6-cyanoindole (3.83 g) was slurried in 60 ml
ethylenediamine, and the mixture sparged with H.sub.2 S. An exotherm was
noted, with a solution resulting. After 8 minutes sparging, product began
to precipitate. The mixture was allowed to cool slowly back to room
temperature, stirred for an additional 2 hours and poured into 175 ml 6N
NaOH. After stirring 15 minutes, crude product was recovered by filtration
with a small amount of 6N NaOH and then water wash. Dried product was
dissolved in 1 liter CH.sub.3 OH, treated with activated carbon, filtered
and the filtrate acidified by sparging with excess dry HCl over a 3 minute
period, precipitating title product. After granulating 10 minutes, title
product was recovered by filtration with methanol and then acetone wash:
5.11 g; m.p. greater than 360.degree.; tlc (2:1:1 butanol:H.sub.2
O:CH.sub.3 CO.sub.2 H) Rf 0.06; ms 329, 300, 233.
Analysis: Calculated for C.sub.20 H.sub.19 N.sub.5.2HCl.2H.sub.2 O: C,
54.79; H, 5.70; N, 15.98; Cl.sup.-, 16.21. Found: C, 54.98; H, 5.74; N,
16.11; Cl.sup.-, 15.93.
PREPARATION 1
Methyl p-Cyanobenzoylacetate
Dimethyl carbonate (126 g, 1.4 moles) was added dropwise to a slurry of NaH
(50% in mineral oil, 13.44 g, 0.28 mole) slurried in 280 ml of dry
dioxane. The reaction mixture was warmed to 80.degree.-85.degree. and
p-cyanoacetophenone (40.7 g, 0.28 mole) in 140 ml dioxane added dropwise
(at about 3/4 addition, mechanical loss due to foaming occurred; such
losses are avoided by slower addition, e.g., over 1 hour). After addition
was complete, heating at 80.degree. was continued for 2 hours and crude
product recovered by hot filtration. The cake was distributed between
dilute CH.sub.3 CO.sub.2 H and ether. The ether layer was separated;
washed in sequence with H.sub.2 O, saturated NaHCO.sub.3, H.sub.2 O and
brine; dried; and stripped to yield title product: 39 g, (68.6%); m.p.
93.degree.-98.degree.; tlc (4:1 toluene:ethyl acetate) Rf 0.58.
Recrystallization of 0.5 g from 2-propanol gave 0.403 g; m.p.
96.degree.-99.degree..
PREPARATION 2
Methyl 3-(p-Cyanophenyl)-2-(p-cyanobenzoyl)propionate
Methyl p-cyanobenzoylacetate (17.77 g, 0.087 mole) and p-cyanobenzyl
bromide (17.16 g, 0.087 mole) were combined in 525 ml DMF under N.sub.2.
K.sub.2 CO.sub.3 (12.1 g, 0.087 mole) was added, the slurry stirred 1.5
hours and finally poured into a mixture of 2.5 liters H.sub.2 O and 0.5
liter ethyl acetate. The organic layer was separated, washed with fresh
H.sub.2 O and then brine, stripped to dryness, and the residue slurried in
ether to yield title product: 14.83 g (53.6%); m.p.
154.degree.-157.degree.; tlc (4:1 toluene:ethyl acetate) Rf 0.44.
PREPARATION 3
1,3-Di(p-cyanophenyl)-1-propanone
Title product of the preceding Preparation (5.80 g, 0.018 mole) was
refluxed under N.sub.2 in 140 ml 1:1 concentrated HCl:THF for 1.25 hours.
The reaction mixture was cooled and title product recovered by filtration:
3.35-3.54 g (71-75%); m.p. 149.degree.-152.degree. C.; tlc (4:1
toluene:ethyl acetate) Rf 0.47.
PREPARATION 4
1,3-Di(p-cyanophenyl)-1-propanol
Title product of the preceding preparation (1.04 g, 0.004 mole) was
slurried in 200 ml anhydrous C.sub.2 H.sub.5 OH. NaBH.sub.4 (0.155 g,
0.004 mole) was added. After 5 minutes, a solution resulted. After 30
minutes, the reaction mixture was stripped to an oil, taken up in ethyl
acetate, washed with H.sub.2 O and then brine, dried and stripped to yield
title product: 1.03 g; m.p. 110.degree.-112.degree..
PREPARATION 5
1,3-Di(p-cyanophenyl)propene
Using a Dean-Stark trap, title product of the preceding Preparation (262
mg, 1 mmole), p-toluenesulfonic acid (270 mg, 1.42 mmole) and 25 ml
toluene were combined and refluxed for 3 hours. The reaction mixture was
stripped to low volume; diluted with ethyl acetate; washed in sequence
with 5% KOH, H.sub.2 O and brine; dried; and stripped to yield 260 mg of
crude product. Chromatography on silica gel with toluene as eluant,
collecting the less polar component, gave purified title product: 150 mg;
m.p. 98.degree.-105.degree..
PREPARATION 6
1,3-Di(p-cyanophenyl)acetone
To dry N-methylpyrrolidone was added Na.sub.2 Fe(CO).sub.4 (25 g, 0.065
mole) and then p-cyanobenzyl bromide (12.7 g, 0.065 mole). A mild exotherm
was noted. After stirring 1 hour, more of the bromide (19.0 g, 0.097 mole)
was added and stirring continued for 21 hours. The reaction mixture was
then poured into 1.8 liters of ether, stirred 1 hour and filtered. The
filtrate was stripped to 200 ml, added slowly to 700 ml 2N HCl, cooled and
crude product recovered by filtration. The partially dried cake (13.3 g)
was taken up in 800 ml hot CH.sub.3 OH and filtered. The filtrate was
boiled down to 200 ml, cooled, and purified title product recovered by
filtration: 4.64 g; m.p. 149.degree.-150.degree.; tlc (4:1 toluene:ethyl
acetate) Rf 0.41.
PREPARATION 7
1,3-Di(p-cyanophenyl)isopropanol
By the method of Preparation 4, title product of the preceding Preparation
(5.2 g, 0.02 mole) was converted to present title product: 5.03-5.18 g
(95.9-98.7%); m.p. 157.degree.-160.degree..
PREPARATION 8
1,3-Di(p-cyanophenyl)isopropyl Mesylate
Title product of the preceding Preparation (1.0 g, 0.0038 mole) and
methanesulfonyl chloride (0.94 g, 0.0082 mole) were combined in 16 ml
pyridine and stirred under N.sub.2 for 4 hours. The reaction mixture was
then diluted with 150 ml H.sub.2 O, granulated and filtered (washing with
H.sub.2 O, 2N HCl and finally fresh H.sub.2 O) to yield title product:
1.19 g (91.7%); m.p. 140.degree.-143.degree.; tlc (4:1 toluene:ethyl
acetate) Rf 0.37.
PREPARATION 9
1,3-Di(p-cyanophenyl)propene
Title product of the preceding Preparation (9.0 g), in a small flask, was
melted under N.sub.2 by immersion in an oil bath at 200.degree. for 5
minutes. The melt was cooled, taken up in ethyl acetate, washed in
sequence with saturated NaHCO.sub.3, H.sub.2 O and brine, dried, treated
with activated carbon, stripped and chromatographed on silica gel with
toluene as eluant to yield title product, 4.4 g; m.p.
99.degree.-107.degree..
PREPARATION 10
2-Methyl-1,3-di(p-cyanophenyl)-2-propanol
Title product of Preparation 6 (2.6 g, 0.01 mole) in 100 ml THF, cooled to
5.degree., was reacted with methylmagnesium chloride (5 ml of 2.8N in
ether, 0.014 mole). After 1 hour, the reaction mixture was added to
saturated NH.sub.4 Cl and extracted with ethyl acetate. The extract was
washed with H.sub.2 O and then brine, stripped to solids (2.64 g) and
triturated with hot toluene to yield title product: 1.48 g; m.p.
147.degree.-148.degree. C.; tlc (4:1 toluene:ethyl acetate) Rf 0.30.
PREPARATION 11
2-Methyl-1,3-di(p-cyanophenyl)propene
By the method of Preparation 5, title product of the preceding Preparation
(1.12 g, 0.004 mole) was converted to present title product: 1.24 g crude;
944 mg after chromatography; oil; ms 258, 243, 140; tlc (4:1 toluene:ethyl
acetate) Rf 0.7.
PREPARATION 12
1,3-Di(p-cyanophenyl)guanidine
Cyanogen bromide (3.18 g, 0.03 mole) and p-cyanoaniline (7.08 g, 0.06 mole)
were combined in 30 ml absolute ethanol and refluxed 16 hours. The
reaction mixture was then cooled and diluted with 170 ml ether. The
resulting slurry was granulated 0.5 hour, filtered with 2N NaOH wash and
the cake dried (6.04 g). The cake was repulped in 300 ml ether, filtered,
repulped in ethyl acetate and again filtered. The ether filtrate was
stripped and the residue recrystallized from 2-propanol to yield title
product: 0.55 g; m.p. 195.degree.-200.degree.; ir(KBr) strong CN signal;
ms 261, 144, 118; tlc (ethyl acetate) Rf 0.48. The ethyl acetate filtrate
was stripped and the residue chromatographed on silica gel with ethyl
acetate as eluant and tlc monitoring, to yield additional title product:
1.32 g; m.p. 196.degree.-200.degree. C.; ms 261, 144, 118.
PREPARATION 13
N-(p-Bromophenyl)-p-cyanophenacylamine
p-Cyanophenacyl bromide (29.8 g, 0.138 mole) and p-bromoaniline (47.13 g,
0.266 mole) were combined with 53.2 g of absolute ethanol and stirred 16
hours. The solution was then diluted with ether and the resulting slurry
filtered. The filter cake was repulped in 500 ml ether, filtered, repulped
in 400 ml acetone and again filtered to yield title product: 17.14 g
(40.9%); m.p. 154.degree.-157.degree..
PREPARATION 14
Dimethyl 1-(p-Bromophenyl)-4-(p-cyanophenyl)pyrrole-2,3-dicarboxylate
Title product of the preceding Preparation (9.45 g, 0.030 mole) and
dimethyl acetylenedicarboxylate (8.52 g, 0.060 mole) were combined with 30
ml CH.sub.3 OH, and the slurry refluxed for 4 hours. The reaction mixture
was cooled in an ice-water bath. The resulting solids were recovered by
filtration and recrystallized from 2-propanol to yield title product: 6.46
g; m.p. 178.degree.-180.degree..
PREPARATION 15
1-(p-Bromophenyl)-4-(p-cyanophenyl)pyrrole-2,3-dicarboxylic Acid
Title product of the preceding Preparation (7.62 g, 0.0173 mole) and LiI
(23.3 g, 0.173 mole) were combined in 150 ml DMF. NaCN (1.70 g, 0.0346
mole) was added portionwise, as the temperature rose to 41.de | | |
