Note: Descriptions are shown in the official language in which they were submitted.
-1- 21 7~0~6
TITLE OF THE INVENTION
SUBSTITUTED IMIDAZOLES AS MODULATORS OF MULTI-DRUG
RESISTANCE
FIELD OF THE INVENTION
The present invention provides novel imidazole derivatives, novel
pharmaceutical compositions containing same, methods of their use, and
methods of their manufacture. Such compounds are pharmacologically
10 useful for restoring the sensitivity of multidrug resistant cells to cancer
chemotherapeutic agents.
BACKGROUND OF THE INVENTION
A major problem in the treatment of malignancies of the blood and
solid tumors is the emergence of tumor cell resistance to chemotherapeutic
agents and the subsequent patient relapse (Bradley et al., Cancer Res. 49:
2790-2796, 1989; Raderer and Scheithaurer, Cancer 72: 3553-3563, 1993).
This resistance causes cancer victims to fail to respond to any antitumor
20 agent, since the transformed tumor cells tend to exhibit clinical resistance
to many drugs. The emergence of the resistant cells to multiple
chemotherapeutic agents occurs either at the initial presentation (intrinsic
resistance) or at the time of relapse (acquired resistance). Both of these
phenomena are known as multi-drug resistance (MDR). MDR is associated
25 with certain alterations in tumor cells resulting in reduced intracellular
anticancer drug accumulation, including reduced membrane perrneability
and increased removal of drug from the cell via an energy-dependent
efflux mechanism. Studies of this mechanism have led to the
characterization of genes capable of conferring resistance to
30 chemotherapeutic agents. One of these genes, the P-glycoprotein or MDR1
gene, has been strongly implicated since overexpression of this gene can
lead to resistance to anthracyclines, vinca alkaloids, and podophyllins, all
important chemotherapeutic agents. MDR1 encodes a 170 kDa membrane
glycoprotein (gp-170 or Pgp) that acts as an ATP-dependent efflux pump,
35 transporting a number of unrelated organic compounds out of the cell
(Juranka et al., FASEB J. 3: 2583-2592, 1989). The level of expression of
-2- 2 1 79086
gp-170 has been shown to correlate with the degree of drug resistance
(Raderer and Scheithaurer, Cancer 72: 3553-3563, 1993). gp-170 appears
to act as a pump that actively extrudes a wide variety of structurally
unrelated compounds, including a full range of antineoplastic drugs.
5 Another ATP-dependent membrane efflux pump, the product of the MRP
gene, has also been implicated in the MDR phenomenon (Krishnamachary
and Center, Cancer Res. 53: 3658-3661, 1993), as have other ATP-
dependent and enzymatic mechanisms.
Drugs of proven antitumor chemotherapeutic value to which MDR
10 has been observed include vinblastine, vincristine, etoposide, teniposide,
doxorubicin (adriamycin), daunorubicin, pliamycin (mithramycin), and
actinomycin D (Jones et al., Cancer (Suppl) 72: 3484-3488, 1993). Many
tumors are intrinsically multi-drug resistant (e.g., adenocarcinomas of the
colon and kidney) while other tumors acquire MDR during the course of
15 therapy (e.g., neuroblastomas and childhood leukemias).
A variety of structurally diverse agents have been identified which
can restore partially or sometimes completely the normal drug sensitivity
to some MDR tumor cells. It is assumed that these chemosensitizers are
effective as a result of their ability to interfere with gp-170, causing a
20 reversal in the increase in drug efflux. Among these agents are calcium
channel blockers (e.g., verapamil and nifedipine), calmodulin inhibitors
(e.g., trifluoperazine), antibiotics (e.g., erythromycin), cardiovascular
agents (e.g., quinidine), noncytotoxic analogs of anthracyclines and vinca
alkaloids, the clinically useful immunosuppressants cyclosporin A (and
25 analogs thereof) and FK-506 (and analogs thereof), and derivatives of
cyclopeptides (Lum et al., Cancer (Suppl) 72: 3502-3514, 1993).
However, at the present time, none of these agents has provided a
significant contribution to the chemotherapeutic index for the treatment of
cancer due to their significant pharmacological effects on other organ
30 systems. An effective therapeutic agent for the reversal of MDR needs to
have efficacy against the membrane pump as well as lack significant
toxicity and other non-specific pharmacological effects.
The present invention describes a family of novel substituted
imidazole derivatives that are effective in increasing the sensitivity of
35 tumor cells resistant to anticancer chemotherapeutic agents, such as
-3~ 2 1 79086
doxorubicin (DOX), taxol, and vinblastine (VLB), and enhancing the
sensitivity of multi-drug resistant cells. These compounds have the effect
of reducing the resistance of MDR tumor cells, and potentiating the
sensitivity of cells to antitumor drugs, such as DOX, taxol, and VLB.
5 These compounds are expected to have broad application in the
chemotherapy of cancer.
It is an object of this invention,therefore, to provide compounds that
have sufficient activity to sensitize multi-drug resistant tumor cells to
antineoplastic agents.
It is an additional object of this invention to provide a method of
sensitizing multi-drug resistant tumor cells using the novel compounds of
the present invention.
A further object is to provide a method of treatment of MDR or
drug-sensitive tumor cells by administering a sufficient amount of a
15 compound of the present invention, prior to, together with, or subsequent
to the administration of an antitumor chemotherapeutic agent.
A further object is to provide pharmaceutical compositions for
increasing the sensitivity of tumor cells to antitumor chemotherapeutic
agents and thus for the treatment of tumors that are susceptible to anti-
20 cancer chemotherapeutic agents but have become resistant to suchchemotherapy. These and other objects will be apparent from the following
description.
25 SUMMARY OF THE INVENTION
The novel compounds of this invention have the general formula
R3 ~R2
~=~
R4 N~,, ~N
R,
4 2 1 79086
and are capable of restoring sensitivity to multi-drug resistant tumor cells.
It is an object of this invention to provide compounds that have
sufficient activity to sensitize multi-drug resistant tumor cells to
5 antineoplastic agents.
It is an additional object of this invention to provide a method of
sensitizing multi-drug resistant tumor cells using the novel compounds of
the present invention.
A further object is to provide a method of treatment of MD~ or
10 drug-sensitive tumor cells by administering a sufficient amount of a
compound of the present invention, prior to, together with, or subsequent
to the administration of an antitumor chemotherapeutic agent.
A further object is to provide pharmaceutical compositions for
increasing the sensitivity of tumor cells to antitumor chemotherapeutic
15 agents and thus for the treatment of tumors that are susceptible to anti-
cancer chemotherapeutic agents but have become resistant to such
chemotherapy.
DETAILED DESCRIPTION OF THE INVENTION
The present invention encompasses compounds of general structural
Formula l
R3 R2
R4--N~,,~N
R,
Formula l
or a pharmaceutically acceptable salt, ester, or prodrug thereof wherein:
s 21 790~6
R1 is:
(a) substituted C1 11 alkyl or substituted C2-l 1 alkenyl, wherein the
substituent is selected from the group consisting of hydrogen, hydroxy,
halo, C1 6 alkyloxy, C1 6 alkylthio, Cl 6 alkylamino, phenyl-C1 6
alkyloxy, phenyl-Cl 6 alkylthio, and phenyl-C1 6 alkylamino; or
(b) aryl-Co l l-alkyl, wherein the aryl group is selected from the group
consisting of phenyl, naphthyl, pyridyl, furyl, pyrryl, thienyl, isothiazolyl,
imidazolyl, benzimidazolyl, tetrazolyl, pyrazinyl, pyrimidyl, quinolyl,
isoquinolyl, benzofuryl, benzothienyl, pyrazolyl, indolyl, isoindolyl,
purinyl, carbazolyl, isoxazolyl, thiazolyl, oxazolyl, ben7thia701yl, and
benzoxazolyl; and mono-, di-, and tri-substituted-aryl Co 1 1-alkyl wherein
aryl is as defined above and wherein the substituents are independently
selected from
(a) trifluoromethyl,
(b) hydroxy,
(c) halo,
(d) phenyl, trans-2-phenylethenyl, 2-phenylethynyl, 2-phenylethyl,
wherein the phenyl group is optionally mono- or di-substituted
with hydroxy, halo, Cl-4 alkyl, or Cl 4 alkyloxy,
(e) carboxy,
(f) amino,
(g) optionally substituted Cl-6 alkyl, Cl 6 alkyloxy, C1 6 alkylthio,
Cl 6 alkylamino, Cl G alkylcarbonyl, Cl 6 alkylcarbonylamino,
C1 6 alkylaminocarbonyl, Cl-6 alkoxycarbonyl, wherein the
substituent is selected from the group consisting of amino,
carboxy, C1 6 alkoxy, C1 6 alkylthio, C1 6 alkylamino, and
di-(Cl 6) alkylamino,
(h) C1 1 lC02R5, Cl l lCONHRs, trans-CH=CHC02Rs, or trans-
CH=CHCONHR5 wherein Rs is hydrogen, C1 11 alkyl, or
phenylCl l 1 alkyl,
(i) carboxymethyleneoxy, and
(j) C1 6 alkoxycarbonylmethyleneoxy;
-6- 2 1 79086
R2 and R3 are each independently:
aryl wherein the aryl group is as defined under the definition of R1 above;
and mono-, di-, and tri-substituted aryl wherein the substituents are
5 independently selected from hydroxy, halo, trifluoromethyl, C1 6 alkyl,
C1 6 alkyloxy, C1 6 alkylthio, amino, C1 6 alkylamino, di-(C1 6 alkyl)-
amino, phenyl-C1 6 alkylamino, and di-(phenyl-C1 6 alkyl) amino;
and R4 is:
(a) hydrogen;
(b) substituted Cl l 1 alkyl or C2-l 1 alkenyl wherein the substituent is
selected from the group consisting of hydrogen, hydroxy, halo, C1 6
15 alkyloxy, C1-6 alkylthio, C1 6 alkylamino, phenyl-C1-6 alkyloxy, phenyl-
C1 6 alkylthio, and phenyl-Cl 6 alkylamino, carboxy, and C1 6
alkoxycarbonyl; or
(c) aryl Co 11 alkyl wherein the aryl group is as defined under the
20 de~lnition of Rl above; and mono-, di-, and tri-substituted-aryl Co ll-alkyl
wherein aryl is as defined above and wherein the substituents are
independently selected from Cl-6 alkyl, trifluoromethyl, hydroxy, halo,
C1 6 alkyloxy, amino, C1 6 alkylamino, aminoCl-6 alkyl, carboxy, and
carboxyC1 6 alkyl.
A preferred embodiment concerns compounds wherein:
R1 is aryl, wherein the aryl group is selected from the group consisting of
phenyl, naphthyl, pyridyl, furyl, pyrryl, thienyl, imidazolyl,
30 benzimidazolyl, pyrimidyl, quinolyl, isoquinolyl, benzofuryl, benzothienyl,
indolyl, thiazolyl, oxazolyl, benzthiazolyl, and benzoxazolyl; and mono-
and di-substituted-aryl wherein aryl is as de~lned above and wherein the
substituents are independently selected from
7 2 1 79086
,
(a) hydroxy,
(b) halo,
(c) phenyl, trans-2-phenylethenyl, wherein the phenyl group is
optionally mono- or di-substituted with hydroxy, halo, C1 4 alkyl,
or C1 4 alkyloxy,
(d) carboxy,
(e) amino,
(f) optionally substituted C1 6 alkyl, C1 6 alkyloxy, C1 6 alkylthio,
C1 6 alkylamino, Cl 6 alkoxycarbonyl, wherein the
substituent is selected from the group consisting of amino,
carboxy, C1 3 alkoxy, C1-3 alkylthio, C1 3 alkylamino, and
di-(C1 3) alkylamino,
(g) trans-CH=CHCO2R5, or trans-CH=CHCONHRS wherein R5 is
hydrogen or C1 6 alkyl,
(h) carboxymethyleneoxy, and
(i) Cl -6 alkoxycarbonylmethyleneoxy;
R2 and R3 are each independently phenyl and mono- and di-substituted
phenyl wherein the substituents are independently selected from hydroxy,
halo, trifluoromethyl, C1 6 alkyl, C1 6 alkyloxy, Cl 6 alkylthio, amino,
C1 6 alkylamino, and di-(Cl 6 alkyl)-amino; and
R4 is hydrogen; substituted C1 6 alkyl, wherein the substituent is selected
from the group consisting of hydrogen, hydroxy, halo, C1 6 alkyloxy,
C1 6 alkylthio, C1 6 alkylamino, carboxy, and C1 6 alkoxycarbonyl; or
mono- or di-substituted aryl C0 3 alkyl, wherein the aryl group is selected
from the group consisting of phenyl, pyridyl, furyl, thienyl, imidazolyl,
thiazolyl, and oxazolyl, and wherein the substituents are independently
selected from hydrogen, C1 6 alkyl, trifluoromethyl, hydroxy, halo, C1 6
alkyloxy, amino, C1 6 alkylamino, aminoCl 6 alkyl, carboxy, and
carboxyC1 6 alkyl.
A still more preferred group comprises compounds wherein:
-8- 2 1 7~086
_
Rl is mono- or di-substituted phenyl, wherein the substituents are selected
from the group consisting of
(a) hydroxy,
(b) trans-2-phenylethenyl, wherein the phenyl group is
optionally mono- or di-substituted with hydroxy, halo, C1 4 alkyl,
or Cl 4 alkyloxy,
(c) carboxy,
(d) optionally substituted Cl 4 alkyl, Cl-4 alkyloxy, Cl 4 alkylthio,
Cl 4 alkylamino, Cl 4 alkoxycarbonyl, wherein the
substituent is selected from the group consisting of amino,
carboxy, Cl 3 alkoxy, C1 3 alkylthio, C1-3 alkylamino, and
di-(Cl 3) alkylamino,
(e) trans-CH=CHCO2R5, or trans-CH=CHCONHR5 wherein R5 is
hydrogen or C 1-4 alkyl,
(f) carboxymethyleneoxy, and
(g) C1 4 alkoxycarbonylmethyleneoxy;
R2 and R3 are each independently phenyl or mono-substituted phenyl
wherein the substituent is selected from the group consisting of Cl 3 alkyl,
C1-3 alkyloxy, amino, Cl 3 alkylamino, and di-(C1 3 alkyl)amino; and
R4 is hydrogen; substituted C1 6 alkyl, wherein the substitutent is selected
from the group consisting of hydrogen, carboxy, and C1 3 alkoxycarbonyl;
or mono-substituted aryl C0 3 alkyl, wherein the aryl group is selected
from the group consisting of phenyl, pyridyl, and imidazolyl and wherein
the substituent is selected from the group consisting of hydrogen, C1 4
alkyl, trifluoromethyl, hydroxy, halo, Cl 4 alkyloxy, amino, Cl 4
alkylamino, carboxy, and carboxyC1 4 alkyl.
Novel compounds of the present invention include but are not limited
to the following compounds:
2-(4-hydroxyphenyl)-1,4,5-triphenyl-imidazole trifluoroacetic acid salt;
9 21 79086
1 -benzyl-2-(4-hydroxyphenyl)-4 ,S-di-(4-methoxyphenyl)-imidazole
tri~uoroacetic acid salt;
2-(4-carboxyphenyl)-4,5 -di-[4-(dimethylaMino)-phenyl]- 1 (H)-imidazole;
4,5-di-[4-(dimethylamino)-phenyl] -2-[4-(methoxycarbonyl)-phenyl]- 1 (H)-
5 imidazole;
2-(4-carboxyphenyl)-4,5-di-[4-(dimethylamino)-phenyl]- 1 -(n-hexyl)-
imidazole;
4,5-di-[4-(dimethylamino)-phenyl] -1 -(n-hexyl)-2-[4-(methoxycarbonyl)-
phenyl]-imidazole;
1 0 2-[4-(trans-2-carboxyethenyl)-phenyl]-4,5-di-[4-(dimethylamino)-phenyl]-
1(H)-imidazole;
4,5-di-[4-(dimethylamino)-phenyl] -2- l 4-[trans-(2-methoxycarbonyl)-
ethenyl]-phenyl } -1 (H)-imidazole;
4,S-di-[4-(dimethylamino)-phenyl]-2-(4-hydroxyphenyl)-l(H)-imidazole;
1 5 4,5-di-[4-(dimethylamino)-phenyl]-2-(4-hydroxyphenyl)-1-(2-phenylethyl)-
imidazole;
2-(4-carboxyphenyl)-4,5-di-[4-(dimethylamino)-phenyl]- 1 -(2-phenylethyl)-
imidazole;
2-[4-(trans-2-carboxyethenyl)-phenyl] -4,5-di-[4-(dimethylamino)-phenyl]-
20 1-(2-phenylethyl)-imidazole;
4,5-di-(4-methoxyphenyl)-2- (4-[trans-(2-methoxycarbonyl)-ethenyl]-
phenyl ) -1-[S-(methoxycarbonyl)-n-pentyl)-imidazole;
2-(~rans-4-stilbenyl)- 1 -[3-(imidazol- 1 -yl)-n-propyl]-4,5-di-(4-
methoxyphenyl)-imidazole;
25 4,5-di-[4-(dimethylamino)-phenyl]-2- ( 4-[trans-(2-methoxycarbonyl)-
ethenyl] -phenyl ) -1-[5 -(methoxycarbonyl)-n-pentyl-] -imidazole;
4,5-di-(4-methoxyphenyl)-2-(4-[3-(dimethylamino)-propyloxy]-phenyl)-1-
(n-hexyl)-imidazole;
4,5-di-(4-methoxyphenyl)-2- ( 4- [3-(dimethylamino)-propyloxy] -phenyl } -1-
30 [3-(imidazol- 1 -yl)-n-propyl] -imidazole.
As used herein "alkyl" is intended to include both branched- and
straight-chain saturated aliphatic hydrocarbon groups having the specified
35 number of carbon atoms, e.g., methyl (Me), ethyl (Et), propyl, butyl,
-lO- 2 1 79086
pentyl, hexyl, heptyl, octyl, nonyl, decyl, iso-propyl (i-Pr), iso-butyl (i-
Bu), tert-butyl (t-Bu), sec-butyl (s-Bu), iso-pentyl, and the like, as well as
saturated alicyclic hydrocarbon groups having the specified number of
carbon atoms, e.g., cyclopentyl, cyclohexyl, and the like. "Alkyloxy" (or
5 "alkoxy") represents an alkyl group having the indicated number of carbon
atoms attached through the oxygen bridge, e.g., methoxy, ethoxy,
propyloxy, and the like. "Alkenyl" is intended to include hydrocarbon
groups of either a straight or branched configuration with one or more
carbon-carbon double bonds which may occur in any stable pOillt along the
10 chain, such as ethenyl, propenyl or allyl, butenyl, pentenyl, 1,5-octadienyl,and the like. The carbon-carbon double bonds may have either the cis- or
trans-configuration.
The term "halo" means fluoro, chloro, bromo, or iodo.
The term "prodrug" refers to a compound that is made more active
15 in vivo.
Pharmaceutically acceptable salts of the compounds of formula 1,
where a basic or acidic group is present in the structure, are also included
within the scope of this invention. When an acidic substituent is present,
such as -COOH and P(O)(OH)2, there can be formed the ammonium,
20 calcium, magnesium, sodium, potassium salt, and the like, for use as the
dosage form. Salts derived from pharmaceutically acceptable organic non-
toxic bases include salts of primary, secondary, and tertiary amines,
substituted amines including naturally occurring substituted amines, cyclic
amines, and basic ion-exchange resins, such as arginine, betaine, caffeine,
25 choline, diethylamine, 2-diethylaminoethanol, 2-dimethylaminoethanol,
ethanolamine, ethylenediamine, N-ethylmorpholine, N-ethylpiperidine,
glucamine, glucosamine, histidine, hydrabamine, isopropylamine, lysine,
methylglucamine, morpholine, piperazine, piperidine, polyamine resins,
procaine, purines, theobromine, triethylamine, trimethylamine,
30 tripropylamine, tromethamine, and the like. When a basic group is
present, such as amino or a basic heteroaryl radical, such as pyridyl, an
acidic salt, such as hydrochloride, hydrobromide, acetate, maleate,
pamoate, methanesulfonate, p-toluenesulfonate, and the like, can be used as
the dosage form.
-11- 21 79086
Also, in the case of the -COOH or -P(O)(OH)2 being present,
pharmaceutically acceptable esters can be employed, e.g., methyl, tert-
butyl, pivaloyloxymethyl, and the like, and those esters known in the art
for modifying solubility or hydrolysis characteristics for use as sustained
5 release or prodrug formulations.
In addition, some of the compounds of the instant invention may
form solvates with water or common organic solvents. Such solvates are
encompassed within the scope of the invention.
The term "therapeutically effective amount" shall mean that amount
10 of drug or pharmaceutical agent that will elicit the biological or medical
response of a tissue, system, animal, or human that is being sought by a
researcher, veterinarian, medical doctor or other clinician.
The compounds of the present invention are conveniently prepared
using either solid-phase or solution phase synthetic methods. These two
15 methods are described generally below and depicted in the following
reaction Schemes. Where appropriate, the synthetic methods utilize readily
available starting materials, reagents, and conventional synthetic
procedures. In these reactions, it is also possible to make use of variants
which are themselves known to those of ordinary skill in this art, but are
20 not mentioned in greater detail.
The solid-phase methods, which are depicted in Schemes 1 and 4,
employ either an aldehyde linker or a FMOC-amino acid linker on solid
supports.
The solid-phase method using an aldehyde linker (Scheme 1)
25 involves synthesis of the substituted imidazoles of the present invention by
reaction of an arylaldehyde linked to a solid support of general formula 3
with a 1,2-diarylethanedione of general formula 1 in the presence of an
amine (R4NH2) of general formula 2 and ammonium acetate and
subsequent cleavage of the desired substituted imidazole from the solid
30 support with trifluoroacetic acid to afford compounds of general formula
4. The solid supports of ~,eneral formula 3 comprise either a
carboxyaldehyde resin or an alkoxyaldehyde resin.
-12- 2 1 79086
SCHEME l
R2 R3
0~0
R4_NH2 NH~OAC /=\ CF3CO~
f , ACOH. 100~C 4 h R4 N~ ~NH
2 20%TFA/CH2C~ ~
I
N
K N
E K
R R
TH
¦WANG ¦ 4
The synthesis of the carboxyaldehyde resin of general formula 3 is
shown in Scheme 2 and employs methodologies described by Lu et al., J.
Org. Chem. 46: 3433,1981. A typical procedure involves reacting 6 mmol
(1 equiv) of Wang resin (S.S. Wang, J. Amer. Chem. Soc. 95: 1328, 1973)
10 in 130 mL of dry solvent (the resin should be swollen in the appropriate
solvent for a minimum of 2 hours prior to coupling; the choice of solvent
is dictated by the solubility of the carboxyaldehyde linker). The solvent
can be dichloromethane, tetrahydrofuran, or N,N-dimethylformamide
(DMF). To this mixture is added 18 mmol of the appropriate
15 carboxyaldehyde (3 equiv), 18 mmol (3 equiv.) of
dicyclohexylcarbodiimide (DCC) or diisopropylcarbodiimide (DIC) and 6
mmol (1 equiv.) of 4-dimethylaminopyridine. The mixture is magnetically
stirred for 48 hours at ambient temperatures. The supernatant is then
filtered off and the resin thoroughly washed wi~h DMF (500 mL),
20 methanol (500 mL), dichloromethane ~500 mL), and methanol (500 mL).
The polymer is dried in vacuo (0.1 mmHg) for 24 hours. Coupling yields
are determined by cleaving 100 mg of the resin with a solution of 20%
-13- 2 1 790û6
trifluoroacetic acid in dichloromethane for 20 minutes at ambient
temperatures. In case of low coupling yields (<70%), the procedure can be
repeated.
SCHEME 2
~~/ -- ¦ WANG ¦ OH
WANG Resin
o
HOJ~ ~
¦ WANG ¦ OH CHO ¦ WANG I OJ~IspAcE
r)cc DMAP, 23~C, 48 h R~
CHO
The carboxyaldehyde may also be coupled to Tentagel PHB resin (E.
10 Bayer, Angew. Chem. Int. Ed. Engl. 30: 113-129, 1991) as the solid
support in place of Wang resin. A typical procedure involves reacting
0.24 mmol (1 equiv) of Tentagel PHB resin in 13 mL of dry solvent (the
resin should be swollen in the appropriate solvent for a minimum of 2
hours prior to coupling; the choice of solvent is dictated by the solubility of
15 the carboxyaldehyde linker). The solvent can be dichloromethane,
tetrahydrofuran, or N,N-dimethylformamide. To this mixture is added 1.2
mmol (5 equiv) of the appropriate carboxyaldehyde, 1.2 mrnol (5 equiv) of
diisopropylcarbodiimide, and 0.24 mmol of 4-dimethylaminopyridine.
The mixture is stirred magnetically for 24 hours at ambient temperatures.
20 The supernatant is then filtered off and the resin thoroughly washed with
DMF (lO0 mL), methanol (100 mL), dichloromethane (100 mL), and
methanol (100 mL). The polymer is dried in vacuo (0.1 mmHg) for 24
hours. Coupling yields are determined by cleaving 100 mg of the resin
with a solution of 20% trifluoroacetic acid in dichloromethane for 20
25 minutes at ambient temperatures.
-14- 217qO~6
-
Examples of carboxyaldehyde linkers used in the generation of resins
and coupling yields are as follows:
CO2H CO2H
CO2H CO2H ~ ~o
~CHO ~ ~CHO
CHO CHO
Coupling
Yields:
Wang Resin 87% 70% 80% 95%
Tentagel PHB 95%
The synthesis of the alkoxyaldehyde resin of general formula 3 is
shown in Scheme 3 and employs methodologies described by Richter and
15 Gadek, Tetrahedron Lett. 35: 4705 (1994). A typical procedure involves
reacting l mmol (1 equiv.) of Wang resin in 4-ethylmorpholine (5 mL)
with 3 mmol (3 equiv.) of the appropriate alkoxyaldehyde in the presence
of 3 mmol (3 equiv.) of triphenylphosphine. The flask is cooled to 0~C and
3 mmol (3 equiv.) of di-isopropyl azodicarboxylate (DIAD) is added
20 dropwise to the mixture. The reaction is placed in a sonicator bath for l
hour at 23~C. Following sonication, the MiXtUre is magnetically stirred for
16 hours at ambient temperatures. The supematant is then filtered off and
the resin thoroughly washed with acetic acid (50 mL), methanol (50 mL),
dichloromethane (50 mL), and methanol (50 mL). The polymer is then
25 dried in vacuo (O.lmmHg) for 24 hours. Coupling yields are determined
by cleaving 100 mg of the resin with a solution of 20% trifluoroacetic acid
in dichloromethane for 20 minutes at ambient temperatures. In case of low
coupling yields (<70%), the procedure can be repeated.
-1S- 21 790~6
SCHEME 3
HO
'E3~
¦ WANG ¦--OH CHO ¦ WANG I--O--~PACERI~
DIAD, Ph3P, 4-elhyl-
... ~,,I,l.olu,~, 23~C, 16 h CHO
Examples of alkoxyaldehyde linkers used in the generation of resins
and coupling yields are as follows:
OH OCH3
~, ~OH
CHO CHO
Coupling Yields 40% 40%
with Wang Resin
The solid-phase method using a FMOC-amino acid linker (Scheme 4)
involves synthesis of the substituted imidazoles by reaction of the 1,2-
ethanediones of general formula 1 with the aldehydes of general formula 2
and the amine-linked resin of general formula 3 in the presence of
15 ammonium acetate followed by treatment with 20% trifluoroacetic acid in
dichloromethane to afford the substituted imidazole compounds of general
formula 4.
-16- 2 1 7~086
. ~ .
SCHEME 4
R2 R3
~ ~ O R3 CF3CO2-
R4 CHO NH4OAc
2 NH2 I.AcOH, 100~C, IS h R2~\N R,
2. 20% TFA/CH~CI~ ~_
N
K N
E K
R E
T T
OH
¦WANG ¦ 4
The synthesis of the FMOC-amino acid linker of general formula 3
is shown in Scheme 5 and employs methodologies described by G.B. Fields
and R.L. Noble, Int. J. Peptide Res. 35: 161 (1990) and references cited
10 therein. A typical procedure involves reacting 3 mmo] (1 equiv) of Wang
resin in dry dichloromethane (92 mL) (the resin should be swollen in
dichloromethane for a minimum of 2 hours prior to coupling) with 9
mmol (3 equiv) of the Fmoc-amino acid in the presence of 9 mmol (3
equiv) of DCC or DIC and 3 mmol (1 equiv) of 4-dimethylaminopyridine.
15 The mixture is stirred magnetically for 48 hours at ambient temperatures.
The supernatant is then filteled off and the resin thoroughly washed with
DMF (500 mL), methanol (500 mL), water (500 mL), methanol (500 mL),
dichloromethane (500 mL), and methanol (500 mL). The polymer is dried
in vacuo (0.1 mmHg) for 24 hours. Coupling yields are determined by
20 cleaving 100 mg of the resin with a solution of 20% trifluoroacetic acid in
dichloromethane for 20 minutes at ambient temperatures. In case of low
coupling yields (<70%), the procedure can be repeated.
-17- 2 1 7qO86
-
SCHEME 5
HOJ~ o
¦ WANG ¦--OH NHFmoc ¦ WANG I OJ~;pACERI~
DIC, DMAP, 23~C, 48 h NHFmoc
An example of an Fmoc-amino acid linker and coupling yield is as
follows:
~ ~ "~NHFmo~
Coupling Yield O
Wang resin 40% ~}
Fmoc: o
The solution-phase methods for preparing the imidazoles of the
present invention are shown in Schemes 6 and 7. The synthesis of the
(lH)-imidazole derivatives is shown in Scheme 6 and involves reaction of
the 1,2-ethanediones of general formula 1 with aldehydes of general
15 formula 2 in the presence of ammonium acetate in acetic acid at 100~C to
afford (lH)-imidazoles of general formula 3.
-18- 2 1 7qO~6
.~
SCHEME 6
R2~ R3
R2 R3 CHO NH~OAc, AcOH, /=\
,~ ~ + ¦ 100 C,4h HN~N
2 R,
The synthesis of the N-substituted imidazole derivatives in solution
phase is shown in Scheme 7 and involves reaction of the 1,2-ethanediones
of general formula 1 with aldehydes of general formula 2 and primary
10 amines of general formula 4 in the presence of ammonium acetate in acetic
acid at 100~C to afford N-substituted imidazoles of general formula 3.
SCHEME 7
R2~ R3
~ O R2 ~R3
AcOH, rellux, 2 h
R4-NH2 + NH40AC ~ RN~,,~N
4 CH0
R
R, 3
The compounds described herein are capable of sensitizing multi-
drug resistant tumor cells to antitumor chemotherapeutic agents, such as
doxorubicin and vinblastine. They also have the ability to potentiate the
sensitivity of tumor cells susceptible to these chemotherapeutic agents.
This invention also relates to a method of sensitizing multidrug-
" -19- 2 1 790~6
resistant tumor cells to antitumor chemotherapeutic agents. It also relates
to a method of increasing the sensitivity of drug-susceptible tumor cells to
antitumor chemotherapeutic agents. In addition, this invention relates to a
method of preventing the emergence of MDR tumor cells during a course
5 of treatment with antitumor chemotherapeutic agents. Finally, this
invention relates to a method of reducing the effective dosage of an
antitumor chemotherapeutic agent during a course of treatment. It has
been found that compounds of Formula l have the ability to increase the
sensitivity of MDR mammalian cells in culture.
Cytotoxic drugs are commonly used as antitumor chemotherapeutic
agents. These agents are also called antiproliferative agents. The desired
effect of cytotoxic drugs is selective cell death with destruction of the
malignant neoplastic cells and relative sparing of normal cells.
Cytotoxic drugs have also proved valuable in the treatment of other
15 neoplastic disorders including connective or autoimmune diseases,
metabolic disorders, dermatological diseases, and DNA virus infections.
Proper use of cytotoxic drugs requires a thorough familiarity with
the natural history and pathophysiology of the disease before selecting the
cytotoxic agent, determining a dose, and undertaking therapy. Each patient
20 must be carefully evaluated, with attention directed toward factors which
may potentiate toxicity, such as overt or occult infections, bleeding
dyscrasias, poor nutritional status, and severe metabolic disturbances. In
addition, the functional condition of certain major organs, such as liver,
kidneys, and bone marrow, is extremely important. Therefore, ~he
25 selection of the appropriate cytotoxic agent and devising an effective
therapeutic regimen is influenced by the presentation of the patient.
Cytotoxic drugs as antitumor chemotherapeutic agents can be
subdivided into several broad categories, including, (l) alkylating agents,
such as mechlorethamine, cyclophosphamide, melphalan, uracil mustard,
30 chlorambucil, busulfan, carmustine, lomustine, semustine, streptozoticin,
and decrabazine; (2) antimetabolites, such as methotrexate, fluorouracil,
fluorodeoxyuridine, cytarabine, azarabine, idoxuridine, mercaptopurine,
azathioprine, thioguanine, and adenine arabinoside; (3) natural product
derivatives, such as vinblastine, vincristine, dactinomycin, daunorubicin,
35 doxorubicin, mithramycin, bleomycin, etoposide, teniposide, and
-20- 2 1 79086
.
mitomycin-C; and (4) miscellaneous agents, such as hydroxyurea,
procarbezine, mititane, and cis-platinum.
Important antitumor chemotherapeutic agents (with the usual
effective dosage) to which clinical multidrug-resistance has been observed
5 include vinblastine (0.l mg per kilogram per week), vincristine (0.0l mg
per kilogram per week), etoposide (35 to 50 mg per square meter per day),
dactinomycin (0.lS mg per kilogram per day), doxorubicin (500 to 600 mg
per square meter~, daunorubicin (65 to 75 mg per square meter per week),
and mithramycin (0.025 mg per kilogram per day). MDR has been shown
10 to occur in vitro as well as in the clinic.
Multidrug-resistant cell lines are easily obtainable for in vitro
determination of drug sensitization by compounds of the present invention.
In vitro potentiation of antineoplastic cytotoxicity by the imidazole
derivatives of the present invention was measured in both CEM/VLBl000
15 and SK/VLBl000 cell lines. The multidrug resistant cell lines were
obtained from Dr. Victor Ling, Ontario Cancer Institute, Toronto, Canada.
The CEM/VLB l000 cell line was maintained as a suspension in minimum
essential medium supplemented with 10% of fetal bovine serum in a
humidied atmosphere of 95% air and 5% CO2 while the SK/VLB l000 cell
20 line was maintained as adherent cells using the identical medium conditions
as the CEM cells. The CEM/VLB l000 cells were seeded at a density of 5
x 104 cells/well in a 96 well microtiter plate while the SK/VLB l000 cell
line was seeded at a density of 2,500 cells/well after trypsinization.
Vinblastine (5 ,ug/mL, for the CEM cells) or Taxol (3 ,ug/mL, for the SK
25 cells) and compound (0.0l to 50 ,uM) were added directly to the wells.
After an incubation of 48 hours in presence of drug, alamar blue (B. Page
et al., Int. J. Oncol. 3: 473-476, l993) was added (20 ,uL to the 200 ~L cell
suspension) for a period of 24 hours after which the fluorescence
(excitation = 530 nM, emission = 590 nM) was read for each well using a
30 "CytoFluor" microtiter fluorometer plate reader. This assay measures the
minimal concentration of compound necessary to enhance the cytotoxicity
(ECso) of vinblastine in the MDR cell line. The compounds of the present
invention had ECso values in the range of 0.3 to 10 ,uM.
Enhancement of 3H-vinblastine accumulation was also measured in
35 the cell line. Corning Easy-Wash 96 well plates were pretreated with PBS
-21- 2 l 7qO~6
and 1% BSA for 60 minutes and then dried. CEM/VLB 1000 cells were
seeded at 2 x 105, 40 ,uL volume. Plates were incubated at 37~C for 30-60
minutes prior to use. The reference reversing agent, verapamil, or the
compound of the present invention was added to the well followed by
5 addition of media containing 3H-vinblastine (filnal concentration = 550
nM). Plates were allowed to incubate for 3 hours at 37~C. Cells were
harvested onto pretreated Wallace filte~nats B (pretreated overnight with
0.1% polyethyleneimine) using a TomTek harvester-96. After filtering,
~e filtermats were allowed to dry completely. Meltix B scintillant was
10 then added to the filterrnats. The filters were then placed in a 90~C oven
for approximately 3-5 minutes and then removed. Scintillant was allowed
to solidify on the filterrnats. ~iltermats were then placed in sample bags
and read on a Wallace BetaPlate scintillation counter. The effect of
compounds of the present invention in the cytotoxicity potentiation assays
15 and vinblastine (VLB) accumulation assay is given in the Table below:
Cytotoxicity Potentiation L3HlVLB Accumulation
(~M) 1 (~M)2
20Example CEM/VLB 1000 SK/VLB l 000 CEM/VLB 1000
Cells Cells Cells
NT3 NT 20
2 NT NT 2
3 10 NT NT
4 0.3 1.0 5.0
3.0 10 12
6 5.0 NT NT
7 10 NT NT
8 0.3 0.3 5.0
9 10 10 20
2.0 20 10
11 10 NT NT
12 10 NT NT
13 0.6 20 NT
-22- 2 1 790~6
14 0.4 I NT
0.6 5 NT
16 2.0 10 NT
17 20 20 NT
1 Values presented are the midpoint (ECso) of the minimum and maximum
cytotoxicity induced by S ,ug/mL vinblastine and the specific compound of
the present invention.
2 Values presented are the midpoint (ECso) of the minimum and maximum
10 increase in accumulation of 3H-vinblastine caused by the specific compound
of the present invention.
3 NT = Not tested.
The modulation of multidrug-resistance demonstrated by the
15 imidazole derivatives described herein provides a method of treatment of
multidrug-resistant tumors. The multidrug-resistance modulatory
properties of the compounds described herein also provides a method for
the prevention of the emergence of multi-drug resistant tumors during the
course of cancer treatment. These same compounds additionally provide a
20 method for reducing the required dosage of an antitumor chemotherapeutic
agent.
All of the methods of this invention involve (1) the administration of
a compound of Formula 1 prior to, together with, or subsequent to the
adrnini.~tration of an antitumor chemotherapeutic agent; and (2) ihe
25 administration of a combination of a compound of Formula 1 and an
antitumor chemotherapeutic agent.
Thus, the compounds of Formula 1 are useful in the treatment of
multidrug-resistant tumor cells or tumor cells in general, either separately
or in combination with an antitumor chemotherapeutic agent. These
30 compounds may be administered orally, topically or parenterally in dosage
unit formulations containing conventional non-toxic pharmaceutically
acceptable carriers, adjuvants, and vehicles. The term parenteral as used
herein includes subcutaneous injections, intravenous, intramuscular,
intrasternal injection or infusion techniques.
-23- 21 790~
.
The present invention also has the objective of providing suitable
topical, oral, and parenteral pharmaceutical formulations for use in the
novel methods of treatment of the present invention. The compounds of the
present invention may be administered orally as tablets, aqueous or oily
5 suspensions, lozenges, troches, powders, granules, emulsions, capsules,
syrups or elixirs. The composition for oral use may contain one or more
agents selected from the group of sweetening agents, flavouring agents,
colouring agents and preserving agents in order to produce
pharmaceutically elegant and palatable preparations. The tablets contain the
10 acting ingredient in admixture with non-toxic pharmaceutically acceptable
excipients which are suitable for the manufacture of tablets. These
excipients may be, for example, (1) inert diluents, such as calcium
carbonate, lactose, calcium phosphate or sodium phosphate; (2) granulating
and disintegrating agents, such as corn starch or alginic acid; (3) binding
15 agents, such as starch, gelatin or acacia; and (4) lubricating agents, such as
magnesium stearate, stearic acid or talc. These tablets may be uncoated or
coated by known techniques to delay disintegration and absorption in the
gastrointestinal tract and thereby provide a sustained action over a longer
period. For example, a time delay material such as glyceryl monostearate
20 or glyceryl distearate may be employed. Coating may also be performed
using techniques described in tl-e U.S. Patent Nos. 4,256,108; 4,160,452;
and 4,265,874 to form osmotic therapeutic tablets for control release.
Formulations for oral use may be in the foml of hard gelatin
capsules wherein the active ingredient is mixed with an inert solid diluent,
25 for example, calcium carbonate, calcium phosphate or kaolin. They may
also be in the form of soft gelatin capsules wherein the active ingredient is
mixed with water or an oil medium, such as peanut oil, liquid paraffin or
olive oil.
Aqueous suspensions normally contain the active materials in
30 admixture with excipients suitable for the manufacture of aqueous
suspension. Such expicients may be (1) suspending agent such as sodium
carboxymethyl cellulose, methyl cellulose, hydroxypropylmethylcellulose,
sodium alginate, polyvinylpyrrolidone, gum tragacanth and gum acacia;
(2) dispersing or wetting agents which may be (a) naturally occurring
35 phosphatide such as lecithin; (b) a condensation product of an alkylene
-24- 2 1 7~0~6
-
oxide with a fatty acid, for example, polyoxyethylene stearate; (c) a
condensation product of ethylene oxide with a long chain aliphatic alcohol,
for example, heptadecaethylenoxycetanol; (d) a condensation product of
ethylene oxide with a partial ester derived from a fatty acid and hexitol
5 such as polyoxyethylene sorbitol monooleate, or (e) a condensation product
of ethylene oxide with a partial ester derived from fatty acids and hexitol
anhydrides, for example polyoxyethylene sorbitan monooleate.
The pharrnaceutical compositions may be in the form of a sterile
injectable aqueous or oleagenous suspension. This suspension may be
10 formulated according to known methods using those suitable dispersing or
wetting agents and suspending agents which have been mentioned above.
The sterile injectable preparation may also a sterile injectable solution or
suspension in a non-toxic parenterally-acceptable diluent or solvent, for
example, as a solution in 1,3-butanediol. Among the acceptable vehicles
15 and solvents that may be employed are water, Ringer's solution, and
isotonic sodium chloride solution. In addition, sterile, fixed oils are
conventionally employed as a solvent or suspending medium. For this
purpose, any bland fixed oil may be employed including synthetic mono-
or diglycerides. In adition, fatty acids such as oleic acid find use in the
20 preparation of injectables.
A compound of Formula 1 may also be administered in the form of
suppositories for rectal administration of the drug. These compositions can
be prepared by mixing the dru~ with a suitable non-irritating excipient
which is solid at ordinary temperature but liquid at the rectal temperature
25 and will therefore melt in the rectum to release the drug. Such materials
are cocoa butter and polyethylene glycols.
The compounds of the present invention may also be administered in
the form of liposome delivery systems, such as small unilamellar vesicles,
large unilamellar vesicles, and multilamellar vesicles. Liposomes can be
30 formed froam a variety of phospholipids, such as cholesterol, stearylamine,
or phosphatidylcholines.
For topical use, creams, ointments, jellies, solutions or suspensions,
etc., containing the compounds of Formula 1 are employed.
Dosage levels of the compounds of the present invention are of the
35 order of about 0.5 mg to about 100 mg per kilogram body weight, with a
-25- 2 1 790~6
preferred dosage range between about 20 mg to about 50 mg per kilogram
body weight per day(from about 25 mg to about 5 gms per patient per
day). The amount of active ingredient that may be combined with the
carrier materials to produce a single dosage will vary depending upon the
5 host treated and the particular mode of administration. For example, a
formulation intended for oral administration to humans may contain 5 mg
to 1 g of an active compound with an appropriate and convenient amount
of carrier material which may vary from about 5 to about 95 percent of
the total composition. Dosage unit forms will generally contain between
10 from about 5 mg to about 500 mg of active ingredient.
It will be understood, however, that the speci~lc dose level for any
particular patient will depend upon a variety of factors including the
activity of the specific compound employed, the age, body weight, general
health, sex, diet, time of administration, route of administration, rate of
15 excretion, drug combination and the severity of the particular disease
undergoing therapy.
The following Examples are intended to illustrate the preparation of
compounds of Formula 1, and as such are not intended to limit the
invention as set forth in the claims appended thereto. Furthermore, the
20 compounds described in the following examples are not to be construed as
forming the only genus that is considerd as the invention, and any
combination of the compounds or their moieties may itself form a genus.
The structure and purity of all final products were assured by at least one
of the following methods: thin-layer chromatography (TLC), mass
25 spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, or
combustion analysis. NMR data is in the form of delta (d) values for major
diagnostic protons, given in parts per million (ppm) relative to
tetramethylsilane (TMS) as internal standard, determined at 400 MHz in
deuteriochloroform (CDC13); conventional abbreviations used for signal
30 shape are: s, singlet; d, doublet; t, triplet; m, multiplet; br., broad; etc.The following abbreviations have also been used: v (volume), w (weight),
L (liter), mL (milliliter), g (gram), mg (milligram), mol (moles), mmol
(millimoles), equiv (equivalents).
The Examples were prepared using either Method A or Method B.
-26- 21 790~36
Method A involves synthesis on a solid support either with
aldehyde linkers as shown in Scheme 1 above or FMOC-amino acid linkers
as shown in Scheme 4 above.
In a typical Method A procedure using an aldehyde linker, to 0.1
5 mmol (1 equiv.) of the carboxyaldehyde resin or alkoxyaldehyde resin was
added 1 mmol (1 equiv.) of 1,2-diarylethanedione, 1 mmol (10 equiv.) of
the amine (R4NH2), 0.14 mmol (1.4 equiv.) of ammonium acetate, and 1.6
mL of acetic acid. The mixture was magnetically stirred for 12 to 15
hours at 100~C. The resin was filtered and washed with dichloromethane
10 (40 mL), N,N-dimethylformamide (20 mL), methanol (20 mL),
dichloromethane (40 mL), and methanol (40 ML). The product was cleaved
from the resin with a solution of 20% trifluoroacetic acid in
dichloromethane for 20 minutes at ambient temperatures. The substituted
imidazoles were purified using reverse-phase HPLC Rainin Dynamax C18
1~ columns and mixtures of water and acetonitrile containing 0.1%
tri~luoroacetic acid as the mobile phase.
In a typical Method A procedure using a FMOC-amino acid linker,
0.1 mmol (1 equiv.) of the FMOC-amino acid resin was deprotected using
20% piperidine in DMF (10 mL) at ambient temperatures for 20 minutes.
20 The resin was washed with DMF (10 mL), dichloromethane (2 x 20 mL),
methanol (2 x 20 mL), and acetic acid (2 x 20 mL). To the deprotected
resin was added 1 mmol (10 equiv.) of the 1,2-diarylethanedione, 1 mmol
(10 equiv.) of ammonium acetate and 1.6 mL of acetic acid. The mixture
was magnetically stirred for 12 to 15 hours at 100~C. The resin was
25 filtered and washed with dichloromethane (40 mL), DMF (20 mL),
methanol (20 mL), dichloromethane (40 mL), and methanol (40 mL). The
product was cleaved from the resin with a solution of 20% trifluoroacetic
acid in dichloromethane for 20 minutes at ambient temperatures. The
substituted imidazoles were purified using reverse-phase HPLC Rainin
30 Dynamax C18 columns and mixtures of water and acetonitrile containing
0.1% tri~luoroacetic acid as the mobile phase.
Method B involves synthesis of the substituted (lH)-imidazoles in
solution phase as shown in Scheme 6 above. In a typical Method B
procedure, 1 mmol (1 equiv.) of the 1,2-ethanedione, 1 mmol (l equiv.)
35 of the aldehyde, and 20 mmol (20 equiv.) of ammonium acetate in glacial
21 79086
acetic acid (9 mL) were heated to reflux for 4 hours. The extent of the
reaction was monitored by thin layer chromatography and nuclear
magnetic resonance (NMR) spectroscopy. Once all starting material had
disappeared, the solution was cooled to 23~C and added dropwise to a
5 vigorously stirred mixture of diethyl ether (200 mL) and saturated aqueous
sodium hydrogencarbonate (200 mL). Ethyl acetate (200 mL) was added,
and the organic layer was separated. The organic layer was washed with
saturated aqueous sodium hydrogencarbonate (200 mL) and saturated brine
solution (200 mL). The aqueous layers were combined and washed with
10 ethyl acetate (200 mL). The combined organic layers were dried over
sodium sulfate, filtered, and solvent removed in vacuo. The derived
imidazoles were puri~led using reverse-phase HPLC Rainin Dynamax C18
columns and mixtures of water and acetonitrile containing 0.1%
trifluoroacetic acid as the mobile phase.
Method C involves synthesis of the N-substituted imidazoles in
solution phase as shown in Scheme 7 above. In a typical Method C
procedure, 2 mmol (1 equiv.) of the 1,2-ethanedione, 2 mmol (1 equiv.)
of the aldehyde, 10 mmol (5 equiv) of the primary amine, and 3 mmol (1.5
equiv.) of ammonium acetate in glacial acetic acid (5 mL) were heated to
20 reflux for 2 hours. The extent of the reaction was monitored by thin layer
chromatography and nuclear magnetic resonance (NMR) spectroscopy.
Once all starting material had disappeared, the solution was cooled to 23~C
and added dropwise to a vigorously stirred mixture of diethyl ether (200
mL) and saturated aqueous sodium hydrogencarbonate (200 mL) or 3.0 N
25 sodium hydroxide (200 mL). Ethyl acetate (200 mL) was added, and the
organic layer was separated. The organic layer was washed with saturated
aqueous sodium hydrogencarbonate (200 mL) or 3.0 N sodium hydroxide
(200 mL) and saturated brine solution (200 mL). The aqueous layers were
combined and washed with ethyl acetate (200 mL). The combined organic
30 layers were dried over sodium sulfate, filtered, and solvent removed in
vacuo. The derived N-substituted imidazoles were purified by
recrystallization, flash chromatography on Merck F60 silica gel, or
reverse-phase HPLC on Rainin Dynamax C18 columns and mixtures of
water and acetonitrile containing 0.1% trifluoroacetic acid as the mobile
35 phase.
-28- ~ 1 ~9~86
EXAMPLE l
~ N~,NH CF3Coi
[~
OH
Prepared by method A. lH-NMR: ~ (6.6, d, 2H), (7.06, d, 4H), (7.15, d,
2H), (7.2-7.4, m, llH).
EXAMPLE 2
OCH3
CH30 ~
,=~ N~NH CF3COi
OH
Prepared by method A. lH-NMR: o (3.7, s, 3H), (3.8, s, 3H), (5.14, s,
2H), (6.7-6.9, m, 9H), (7.09, d, 2H), (7.21, d, 2H), (7.3, d, 2H), (7.4, d,
1 5 2H).
EXAMPLE 3
-29- 2 1 790~36
_
NMe2
Me2N
N~N
CO2H
Prepared by method A. 1H-NMR: ~ (2.9, s, 12H), (6.7, d, 4H), (7.25, d,
5 4H), (7.95, dd, 4H).
EXAMPLE 4
Me2N ~ NMe2
N~N
CO2Me
Prepared by method A, followed by reaction with trimethylsilyl-
diazomethane in 4:1 methanol-benzene. IH-NMR: ~ (2.9, s, 12H), (4.9, s,
3H), (6.7, d, 4H), (7.4, d, 4H), (7.9, d, 2H), (8.05, d, 2H).
EXAMPLE S
2 1 79~6
NMe2
Me2N
CH3(CH2)5 \~
CO2H
Prepared by method A. 1H-NMR: ~ (0.6, t, 3H), ), (0.9-1.0, m, 6H), (1.3,
m, 2H), (2.8, s, 6H), (3.0, s, 6H), (3.78, dd, 2H), (6.58, d, 2H), (6.72, dd,
5 4H), (7.19, d, 2H), (7.21, d, 2H), (7.4, d, 2H).
EXAMPLE 6
Me2N NMe2
CH3(CH2)5 \~
CO2Me
Prepared by method A, followed by reaction with trimethylsilyl-
diazomethane in 4:1 methanol-benzene. 1H-NMR: ~ (0.6, t, 3H), (0.9-1.0,
m, 6H), (1.3, m, 2H), (2.8, s, 6H), (3.0, s, 6H), (3.8, dd, 2H), (3.9, s, 3H),
(6.58, d, 2H), (6.78, d, 2H), (7.24, d, 2H), (7.42, d, 2H), (7.78, d, 2H),
15 (8.05, d, 2H).
-31- 2 ~ 790~36
-
EXAMPLE 7
NMe
Me2N ~ 2
H N~N
CH=CHCO2H
5 Prepared by method A. lH-NMR: ~ (2.9, s, 12H), (6.3, d, lH), (6.62, d,
4H), (7.4, broad d, 4H), (7.43, d, 2H), (7.6, d, lH), (7.9, d, 2H).
EXAMPLE 8
- NMe2
Me2N ~\ /
H~N~,~N
1 0 CH=CHCO2Me
Prepared by method B, followed by reaction with
trimethylsilyldiazomethane in 4:1 methanol-benzene. IH-NMR: ~ (2.9, s,
12H), (3.78, s, 3H), (6.35, d, lH), (6.6, d, 4H), (7.38, broad d, 4H), (7.4,
15 d, 2H), (7.6, d, lH), (7.8, d, 2H).
-32- 2 1 790~6
EXAMPLE 9
NMe2
,7
H~N~.~N
OH
5 Prepared by method A. lH-NMR: ~ (2.9, s, 12H), (6.75, d, 2H), (6.9, d,
4H), (7.3, d, 4H), (7.65, d, 2H).
EXAMPLE 10
NMe2
Me2N ~ ~ ~ ,J
N N
OH
Prepared by method A. lH-NMR: ~ (2.5, t, 2H), (2.9, s, 6H), (3.0, s, 6H),
(4.2, d, 2H), (6.58, d, 2H), (6.72, dd, 2H), (6.9, m, 4H), (7.1, m, SH),
(7.19, d, 2H), (7.25, d, 2H).
1~ .
EXAMPLE I 1
-33- 21 79Q~6
Me2N~NMe2
N~N
CO2H
Prepared by method A. lH-NMR: ~ (2.5, t, 2H), (2.9, s, 6H), (3.0, s, 6H),
5 (4.2, d, 2H), (6.58, d, 2H), (6.72, dd, 2H), (6.9, d, 2H), (7.1, m, 3H),
(7.19, d, 2H), (7.35, dd, 4H), (8.05, d, 2H).
EXAMPLE 12
Me2N~ NMe2
N~N
1 0 CH=CHCO2H
Prepared by method A. lH-NMR: ~ (2.5, t, 2H), (2.9, s, 6H), (3.0, s, 6H),
(4.2, d, 2H), (6.4, d, lH), (6.5, d, 2H), (6.7, d, 2H), (6.9-7.6, m, 14H).
EXAMPLE 13
-34-
2 1 790û6
-
MeO OMe
MeO J~ ,, N~N
CH=CHCO2Me
Prepared by method A, followed by reaction with
trimethylsilyldiazomethane in 4:1 methanol-benzene. lH-NMR: ~ (0.9, m,
5 2H), (1.3, m, 4H), (2.05, t, 2H), (3.55, s, 3H), (3.7, s, 3H), (3.8, s, 3H),
(3.85, s, 3H), (3.85, t, 2H), (6.45, d, lH), (6.7, d, 2H), (6.95, d, 2H), (7.25,d, 2H), (7.4, d, 2H), (7.6, d, 2H), (7.7, d, 2H), (7.7, d, IH).
EXAMPLE 14
N~N ~ N~N
~3
-35- 2~ 790~6
' .
Prepared by method C. IH-NMR: ~ (1.8, m, 2H), (3.6, t, 2H), (3.7, s, 3H),
(3.84, s, 3H), (3.9, t, 2H), (6.42, s, lH), (6.72, d, 2H), (6.89, s, lH), (6.98,d, 2H), (7.14, m, 2H), (7.24, m, 3H), (7.35, t, 2H), (7.44, d, 2H), (7.52, d,
2H), (7.58, s, 3H).
EXAMPLE 15
Me2N~ ~NMe2
O ~
MeO~~ N~N
CH=CHCO2Me
10 Prepared by method A, followed by reaction with
trimethylsilyldiazomethane in 4:1 methanol-benzene. lH-NMR: ~ (0.9, m,
2H), (1.3, m, 4H), (2.8, s, 6H), (3.0, s, 6H), (3.58, s, 3H), (3.8, s, 3H),
(3.85, t, 2H), (6.45, d, lH), (6.58, d, 2H), (6.75, d, 2H), (7.2, d, 2H), (7.4,
d, 2H), (7.6, d, 2H), (7.7, d, 2H), (7.7, d, IH).
EXAMPLE 16
-36- 2 1 790~6
OMe
~ N~N
[~3
~O~
~N~
Prepared by method C. lH-NMR: ~ (0.7, t, 3H), (0.9, m, 4H), (1.1, m,
2H), (1.3, m, 2H), (1.9, m, 2H), (2.2, s, 6H), (2.45, t, 2H), (3.7, s, 3H),
5 (3.75, t, 2H), (3.84, s, 3H), (4.05, t, 2H), (6.72, d, 2H), (6.98, d, 4H),
(7.22, d, 2H), (7.4, d, 2H), (7.52, d, 2H).
EXAMPLE 17
37- 2 t 790~6
_
OMe
MeO ~
~N ~ N~N
~0
~N\
Prepared by method C. lH-NMR: ~ (1.7, m, 2H), (1.92, m, 2H), (2.2, s,
6H), (2.4, t, 2H), (3.5, t, 2H), (3.66, s, 3H), (3.78, t, 2H), (3.82, s, 3H),
5 (4.05, t, 2H), (6.42, s, lH), (6.72, d, 2H), (6.85, s, lH), (6.91, m, 4H),
(7.04, s, lH), (7.2, d, 2H), (7.41, d, 2H),
