[0001] The present invention relates to compound of formula I, 4-(diarylmethyl)-1-piperazinyl
derivatives with alkenyl moiety substituted at the 1-position of the piperazine unit.

wherein X, Y, X' & Y' are selected from hydrogen, halogen, linear, branched or cyclo
alkyl, alkyloxy and haloalkyl group; R
1 and R
2, are both hydrogen, R
3 and R
4 are selected from hydrogen linear, branched or cyclo alkyl groups and aryl, and optionally
R
3 and R
4 together with the carbons to which they are attached form an aryl ring with a proviso
that when R
3 & R
4 together do not form part of said aryl ring they may exist in either E or Z configuration;
R
5 is (CH
2)
n-O-CH
2-CO-Z wherein n is 1 to 6; Z is selected from OH, OR, NRR', N(OR)R', wherein R & R'
are selected from hydrogen, linear, branched or cyclo alkyl groups or C2 to C6 alkenyl
or alkynyl groups; and m is selected from 1 to 6;
and pharmaceutically acceptable salts thereof.
[0002] The R
5 group in formula I represents an alkyloxy acetic acid and its derivatives, such as
an ester, an amide, a hydroxamic acid or a hydrazide. These compounds include their
non-toxic pharmaceutically acceptable acid addition salts and those derived from alkali
metals, alkaline earth metals or amines including hydroxyalkyl and polyhydroxyalkyamines.
[0003] The compound of the present invention is an antihistaminic compound useful in the
treatment of histamine mediated diseases.
PRIOR ART
[0004] United States patent number
4525358 (Indian reference not available) discloses an antihistaminic compound cetirizine

which is used as an antiallergic, antihistaminic, bronchodilator or antispasmodic
agent. It is useful in patients suffering from indications requiring the above mentioned
effects. However, it is devoid of an olefinic side chain on the piperazine ring.
[0005] PCT publication WO 01/79188 discloses novel compounds of formula

which are more hydrophobic in nature than cetirizine as Y is substituted or unsubstituted
carbocyclic, a heterocyclic, a polycyclic hydrocarbonyl, a heteropolycyclic, a carbocyclic
arenyl, a heteropolycyclic arenyl or theophylline group.
[0006] PCT publication WO 00/58295 discloses new compounds of formula

for treating asthma, allergy and inflammatory disorders, wherein W or a substituent
on the phenyl ring is a hydroxylamine.
[0007] European patent number 598123 discloses piperazine derivatives of formula

which are different from compound of formula I as they do not contain an olefinic
side chain on the piperazine ring.
[0008] FR 2 082 168 discloses compounds of the formula

Where A is a bond or a saturated or unsaturated divalent C1-C6 hydrocarbon, B is a
divalent C1 to C5 saturated hydrocarbon group and R represents any of a broad range
of substituents of the aryl ring.
[0009] We have now found novel antihistaminic compounds.
OBJECTS OF THE INVENTION:
[0010] The object of the present invention is to provide antihistaminic compound of formula
I and pharmaceutically acceptable salts thereof.
SUMMARY OF INVENTION:
[0011] A compound of formula I

wherein X, Y, X' & Y' are selected from hydrogen, halogen, linear, branched or cyclo
alkyl, alkyloxy and haloalkyl group; R
1 and R
2, are both hydrogen, R
3 and R
4 are selected from hydrogen linear, branched or cyclo alkyl groups and aryl, and optionally
R
3 and R
4 together with the carbons to which they are attached form an aryl ring with a proviso
that when R
3 & R
4 together do not form part of said aryl ring they may exist in either E or Z configuration;
R
5 is (CH
2)
n-O-CH
2-CO-Z wherein n is 1 to 6; Z is selected from OH, OR, NRR', N(OR)R', wherein R & R'
are selected from hydrogen, linear, branched or cyclo alkyl groups or C2 to C6 alkenyl
or alkynyl groups; and m is selected from 1 to 6;
and pharmaceutically acceptable salts thereof.
DETAILED DESCRIPTION OF THE INVENTION:
[0012] Accordingly, the present invention provides compound of formula I

wherein X, Y, X' & Y' are selected from hydrogen, halogen, linear, branched or cyclo
alkyl, alkyloxy and haloalkyl group; R
1 and R
2, are both hydrogen, R
3 and R
4 are selected from hydrogen linear, branched or cyclo alkyl groups and aryl, and optionally
R
3 and R
4 together with the carbons to which they are attached form an aryl ring with a proviso
that when R
3 & R
4 together do not form part of said aryl ring they may exist in either E or Z configuration;
R
5 is (CH
2)
n-O-CH
2-CO-Z wherein n is 1 to 6; Z is selected from OH, OR, NRR', N(OR)R', wherein R & R'
are selected from hydrogen, linear, branched or cyclo alkyl groups or C2 to C6, alkenyl
or alkynyl groups; and m is selected from 1 to 6;
and pharmaceutically acceptable salts thereof.
[0013] The compound of the present invention wherein R
3 and R
4 together with the carbons to which they are attached form a monocyclic saturated
or aryl or substituted aryl or heteroaryl or substituted heteroaryl ring containing
one or more hetero atoms selected from N, S and O with a ring size ranging from 3
to 6 is referred to herein as compound of formula II

[0014] The preferred compound of formula II is wherein the ring is a benzene ring

[0015] The compound of the present invention wherein R
3 and R
4 are in E configuration, is referred to herein as compound of formula III,

[0016] Preferably, compound of formula I wherein
X, Y, X' & Y' are selected from hydrogen, chloro and fluoro;
R
1 and R
2, are hydrogen;
R
3 and R
4 are hydrogen existing in the
E or
Z configuration or optionally R
3 and R
4 together with the carbons to which they are attached form a benzene ring; and
R
5 is CH
2-O-CH
2-CO-Z wherein Z is selected from OH and OR wherein R may be selected from methyl,
ethyl and isopropyl;
;and m is 1.
[0017] Compounds of the present invention may be prepared using different routes. For instance,
as illustrated in Schemes 1 to 4.
[0018] In process as illustrated in Scheme 1

compound of formula IV,

wherein X,Y,X', Y', R
1 and R
2 are as described above, is N-alkylated with compound of formula V wherein L is a
leaving group selected from halo, or an alkyl or arylsulfonate group for e.g. methanesulfonate
or p-toluenesulfonate and the like, to give compound of formula VI,

which is then reacted with X
1CH
2COZ wherein X
1 is halo group such as chloro to yield compound of formula I.
[0019] The starting material, compound of formula IV, may be prepared by known prior art
such as
Baltzly, R. et al, J. Org. Chem., 14, 775, 1949;
Yung, D.K et al J. Pharm. Sci., 67(7), 1978.
[0020] In process as illustrated in Scheme 2,

compound of formula I wherein R
3 and R
4 together form ring selected from cyclic, aryl or substituted aryl, heterocyclic aryl
groups or substituted heterocyclic aryl groups containing one or more hetero atoms
(viz., N, S, O) with a ring size ranging from 3 to 6, referred to herein as compound
of formula II may be prepared by a process similar to that described above wherein
compound of formula IV is N-alkylated with compound of formula VII wherein L is a
leaving group selected from halo, or an alkyl or arylsulfonate group for e.g. methanesulfonate
or p-toluenesulfonate and the like, to give compound of formula VIII,

which is then reacted with X
1CH
2COZ wherein X
1 is halo group such as chloro to yield compound of formula I.
[0021] In process as illustrated in Scheme 3,

compound of formula I wherein R
3 and R
4 are hydrogen and in E or Z configuration, may be prepared by N-alkylating compound
of formula IV with compound of formula IX,

wherein P maybe H or any protecting group such as acetate to give compound of formula
X, which is reduced to give compound of formula XI. Compound of formula XI is then
reacted, after removing the protecting group wherever required, with X
1CH
2COZ wherein X
1 is halo group such as chloro to yield compound of formula I.

[0022] In process as illustrated in Scheme 4,

compound of formula I wherein R
3 and R
4 are in E configuration may be prepared by N-alkylating compound of formula IV with
compound of formula XII to give compound of formula XIII which is then reduced to
yield compound of formula XIV.

[0023] Compound of formula XIV is treated with X
1CH
2COZ wherein X
1 is halo group such as chloro to yield compound of formula I.

[0024] Another aspect of the present invention relates to formulation of compound of formula
I in suitable form, which can be administered to the patient.
[0025] Compounds of the present invention can be provided as a pharmaceutical composition
for use in the treatment of histamine mediated diseases. The composition comprises
compound of formula I and pharmaceutically acceptable ingredients.
[0026] Such compositions may be prepared by admixing compound of formula I and pharmaceutically
acceptable ingredients. Usually the compositions are adapted for oral administration.
However, they may be adapted for other modes of administration, for example parenteral
administration, sublingual, transdermal or opthalmic administration.
[0027] The compositions may be in the form of tablets, capsules, powders, granules, nasal
spray, aerosols, lozenges, ointments, creams, transdermal patches, reconstitutable
powders, or liquid preparations, such as oral or sterile solutions or suspensions.
[0028] In order to obtain consistency of administration it is preferred that a composition
of the invention is in the form of a unit dose.
[0029] Unit dose presentation forms for oral administration may be tablets and capsules
and may contain conventional excipients such as binding agents, for example syrup,
acacia, gelatin, sorbitol, tragacanth, or polyvinylpyrrolidone; fillers, for example
lactose, sugar, maize-starch, calcium phosphate, sorbitol or glycine; tabletting lubricants,
for example magnesium stearate; disintegrants, for example starch, polyvinylpyrrolidone,
sodium starch glycollate or microcrystalline cellulose; or pharmaceutically acceptable
wetting agents such as sodium lauryl sulphate.
[0030] The compositions are preferably in a unit dosage form in an amount appropriate for
the relevant daily dosage.
[0031] The solid oral compositions may be prepared by conventional methods of blending,
filling or tabletting known to those skilled in this art. Repeated blending operations
may be used to distribute the active agent throughout those compositions employing
large quantities of fillers. Such operations are of course conventional in the art.
The tablets may be coated according to methods well known in normal pharmaceutical
practice.
[0032] Oral liquid preparations may be in the form of, for example, emulsions, syrups, or
elixirs, or may be presented as a dry product for reconstitution with water or other
suitable vehicle before use. Such liquid preparations may contain conventional additives
such as suspending agents, for example sorbitol, syrup, methyl cellulose, gelatin,
hydroxyethylcellulose, carboxymethylcellulose, aluminum stearate gel, hydrogenated
edible fats; emulsifying agents, for example lecithin, sorbitan monooleate, or acacia;
non-aqueous vehicles (which may include edible oils), for example almond oil, fractionated
coconut oil, oily esters such as esters of glycerine, propylene glycol, or ethyl alcohol;
preservatives, for example methyl or propyl p-hydroxybenzoate or sorbic acid; and
if desired conventional flavoring or coloring agents.
[0033] For parenteral administration, fluid unit dosage forms are prepared utilizing the
compound and a sterile vehicle, and, depending on the concentration used, can be either
suspended or dissolved in the vehicle. In preparing solutions the compound can be
dissolved in water for injection and filter sterilized before filling into a suitable
vial or ampoule and sealing. Advantageously, adjuvants such as a local anaesthetic,
a preservative and buffering agent can be dissolved in the vehicle. To enhance the
stability, the composition can be frozen after filling into the vial and the water
removed under vacuum.
[0034] For ophthalmic administration, sterile solution or suspension can be prepared. Ophthalmic
solution can be prepared by dissolving the compound in water for injection along with
suitable preservative, chelating agent, osmogen, viscosity enhancing agent, antioxidant
and buffering agent. Solution is aseptically filtered and filled into suitable vials
or bottles of suitable material. Similarly suspension can be prepared by aseptically
dispersing the sterile compound in a sterile aqueous vehicle containing suitable preservative,
chelating agent, osmogen, suspending agent, antioxidant and buffering agent. Preservative-free
unit doses can also be prepared in similar way for solution as well as suspension
and aseptically filled into unit dose containers.
[0035] Compositions may contain from 0.1 % to 99.0% by weight, preferably from 10-60% by
weight, of the active material, depending upon the method of administration.
[0036] Composition may, if desired, be in the form of a pack accompanied by written or printed
instructions for use.
[0037] The compound of formula I on being formulated is useful for various histamine mediated
diseases. IC
50 was determined for the compounds prepared by the present invention.
EXAMPLES
Example 1
4-{4-[Bis-(4-fluorophenyl)methyl]piperazin-1-yl}-(Z)-but-2-en-1-ol, (VIa, X=X'=4-F;
Y=Y'=R1=R2=R3=R4=H; m=n=1):
[0038] A solution containing 1-[bis-(4-fluorophenyl)methyl]piperazine (140g, 0.485mol),
toluene (700ml), 4-chloro-2-butene-1-ol (67.25g, 0.631mol), and diisopropylethylamine
(125.8g, 0.971mol) is stirred at 47-49° C for 5hrs. Water (350ml) is added to the
reaction mixture, the organic layer separated and the aqueous layer extracted with
dichloromethane (2x200ml). The combined organic layer is washed with water (200ml),
and concentrated to obtain crude product which is purified by flash column chromatography
on silica gel using dichloromethane-methanol (9.6:0.4) as mobile phase to obtain pure
product.
[0039] 1H-NMR (CDCl
3, δppm): 2.15-2.80 (m, 8H), 3.01 (d, J=4.90Hz, 2H), 4.13 (d, J=3.96Hz, 2H), 4.20 (s,
1H), 5.55-5.75 (m, 1H), 5.75-6.00 (m, 1H), 6.96 (t, J=8.14Hz, 4H), 7.20-7.40 (m, 4H).
Example 2
(R,S)-4-{4-[(4-chlorophenyl)phenylmethyl]piperazin-1-yl}-(Z)-but-2-en-1-ol, [VIb(R,S),
X=Cl; X'=Y=Y'=R1=R2=R3=R4=H; m=n=1]:
[0040] (R,S)-1-[(4-chlorophenyl)phenylmethyl]piperazine 8.0g is converted to
(R,S)-4-{4-[(4-chlorophenyl)phenylmethyl]piperazin-1-yl}-(Z)-but-2-en-1-ol in a manner
similar to example 1. Crude product is obtained as a syrupy mass, which is purified
by flash column chromatography on silica gel using toluene-methanol (9:1) as mobile
phase to obtain pure product.
[0041] 1H-NMR (CDCl
3, δppm): 2.10-2.90 (m, 8H), 3.01 (d, J=5.75Hz, 2H), 4.13 (d, J=-5.25Hz, 2H), 4.19
(s, 1H), 5.50-5.75 (m, 1H), 5.75-6.00 (m, 1H), 7.00-7.40 (m, 9H).
Example 3
4-{4-Benzhydrylpiperazin-1-yl}-(Z)but-2-en-1-ol, (VIc, X=X'=Y=Y'=H; R1=R2=R3=R4=H;
m=n=1):
[0042] A solution containing 1-benzhydrylpiperazine (3g, 0.0119mol), toluene (20ml), 4-chloro-2-butene-1-ol
(1.65g, 0.0155mol), diisopropylethylamine (3.81g, 0.0295mol), and DMF (3ml) is stirred
at 55-60° C for 5hrs. The reaction mass is quenched with water (20ml), organic layer
separated and the aqueous layer extracted with dichloromethane (2x20ml). The organic
extract is washed with water (10ml), and concentrated to obtain crude product, which
is purified by flash column chromatography on silica gel using dichloromethane-methanol
(9.3:0.7) as mobile phase to obtain pure product.
[0043] 1H-NMR (CDCl
3, δppm): 2.10-2.80 (m, 8H), 3.01 (d, J=5.52Hz, 2H), 4.13 (dd, J
1=5.19Hz, J
2=0.68Hz, 2H), 4.21 (s, 1H), 5.50-5.75 (m, 1H), 5.75-6.00 (m, 1H), 7.00-7.50 (m, 10H).
Example 4
4-{4-[Bis-(2,4-difluorophenyl)methyl]piperazin-1-yl}-(Z)-but-2-en-1-ol, (VId, X=X'=Y=Y'=F;
R1=R2=R3=R4=H; m=n=1):
[0044] 1-[Bis-(2,4-difluorophenyl)methyl]piperazine (20.0g, 0.0617mol) is converted to 4-{4-[bis-(2,4-difluorophenyl)methyl]piperazin-1-yl}-(Z)-but-2-en-1-ol
in a manner similar to example 1. Crude product is obtained as a syrupy mass, which
is purified by flash column chromatography on silica gel using toluene-methanol (9:1)
as mobile phase to obtain pure product.
[0045] 1H-NMR (CDCl
3, δppm): 2.20-2.85 (m, 8H), 3.02 (dd, J
1=6.00Hz, J
2=0.74Hz, 2H), 4.14 (dd, J
1=5.31Hz, J
2=0.98Hz, 2H), 4.94 (s, 1H), 5.50-5.75 (m, 1H), 5.75-6.00 (m, 1H), 6.55-7.00 (m, 4H),
7.30-7.60 (m, 2H).
Example 5
4-{4-[Bis-(4-chlorophenyl)methyl]piperazin-1-yl}-(Z)-but-2-en-1-ol, (VIe, X=X'=Cl;
Y=Y'=R1=R2=R3=R4=H; m=n=1):
[0046] 1-[Bis-(4-chlorophenyl)methyl] piperazine (5.044g) is converted to 4-{4-[bis-(4-chlorophenyl)methyl]piperazin-1-yl}-(Z)-but-2-en-1-ol
in a manner similar to example 1. The crude product obtained is purified by flash
column chromatography on silica gel using toluene-methanol (9:1) as mobile phase to
obtain pure product.
[0047] 1H-NMR (CDCl
3, δppm): 2.10-2.80 (m, 8H), 3.01 (d, J=5.87Hz, 2H), 4.13 (dd, J
1=5.26Hz, J
2=0.88, 2H), 4.18 (s, 1H), 5.50-5.75 (m, 1H), 5.75-6.00 (m, 1H), 7.00-7.40 (m, 8H).
Example 6
{2-{4-[Bis-(4-fluorophenyl)methyl]piperazin-1-yl-methyl}phenyl}methanol (VIIIa, X=X'=F;
Y=Y'=R1=R2=H; m=n=1, A=benzene ring):
[0048] 1-[Bis-(4-chlorophenyl)methyl] piperazine (5.0g, 0.0173mol) is converted to {2-{4-[bis-(4-fluorophenyl)methyl]piperazin-1-ylmethyl}phenyl}methanol
using 2-(chloromethyl)benzyl alcohol, in a manner similar to example 1. The crude
product obtained as brownish yellow syrup is purified by flash column chromatography
on silica gel using toluene-methanol (9.2:0.8) as mobile phase to obtain pure product.
[0049] 1H-NMR (CDCl
3, δppm): 2.00-2.80 (m, 8H), 3.6 (s, 2H), 4.18 (s, 1H), 4.57 (s, 2H), 6.70-7.03 (m,
4H), 7.05-7.40 (m, 8H).
Example 7
{2-{4-[(4-chlorophenyl)phenylmethyl]piperazin-1-ylmethyl}phenyl}methanol, (VIIIb,
X=Cl; X'=Y=Y'=R1=R2=H; m=n=1, A=benzene ring):
[0050] 1-[Bis-(4-chlorophenyl)methyl] piperazine (4.0g, 0.0140mol) is converted to {2-{4-[(4-chlorophenyl)phenylmethyl]piperazin-1-ylmethyl}phenyl}methanol
in a manner similar to example 1. The crude product obtained is purified by flash
column chromatography on silica gel using toluene-methanol (9.2:0.8) as mobile phase
to obtain pure product as a white foamy solid.
[0051] 1H-NMR (CDCl
3, δppm): 2.00-2.80 (m, 8H), 3.60 (s, 2H), 4.16 (s, 1H), 4.56 (s, 2H), 6.86 (br, exchangeable
by D
2O), 6.95-7.40 (m, 13H).
Example 8
4-{4-[Bis-(4-fluorophenyl)methyl]piperazin-1-yl}but-2-yn-1-ol (Xa, X=X'=4-F; Y=Y'-R1=R2=H;
m=1):
Method A: Using 4-chloro-2-butyne-1-ol
[0052] To a solution containing 1-[bis-(4-fluorophenyl)methyl]piperazine (300g, 1.040mol),
tetrahydrofuran (1800ml) and diisopropylethylamine (242.1g, 1.873mol) is added dropwise
4-chloro-2-butyne-1-ol (130.5g, 1.248mol) during 1hr at 10-15° C. After stirring at
10-15° C for 1.5hr the temperature is gradually raised to 25-30° C and stirred for
further 7hr. Thereafter, a solution of citric acid (437.3g, 2.08mol) in water (500ml)
is added and the mixture is concentrated under reduced pressure at below 60° C to
remove most of the solvent. The resulting aqueous mass is washed with toluene (2x400ml),
basified to pH=9-10 and the product extracted into dichloromethane (2x400ml). The
dichloromethane layer is washed with water (300ml) and degassed to obtain crude product,
which is purified by flash column chromatography on silica gel using toluene-methanol
(9:1) as mobile phase.,
[0053] 1H-NMR (CDCl
3, δppm): 1.84 (br, 1H, D
2O exchangeable), 2.20-2.80 (m, 8H), 3.31 (t, J=1.84Hz, 2H), 4.21 (s, 1H), 4.29 (t,
J=1.80Hz, 2H), 6.80-7.05 (m, 4H), 7.10-7.50 (m, 4H).
Method B: Using 2-butyne-1,4-diol
[0054] A solution of methanesulfonyl chloride (48.69g, 0.425mol) and tetrahydrofuran (100ml)
is added dropwise to a stirred solution of 2-butyne-1,4-diol (100g, 1.162mol) and
diisopropylethylamine (62.45g, 0.483mol) in tetrahydrofuran (400ml) during 2hr at
0-5°C. After 1hr stirring at 0-5°C for 1hr the temperature is raised to 25-30°C and
stirred for further 1hr. The reaction mixture is then cooled to 10-15°C, and to it
is added diisopropylethylamine (99.34g, 0.769mol), followed by 1-[bis-(4-fluorophenyl)methyl]piperazine
(110.81g, 0.384mol) in portions during 30min. The reaction mass is stirred at 10-15°
C for 1hr and then at 25-30° C for furthers 8hrs. Toluene (500ml) is added to it and
the contents washed with water (2x400ml). Thereafter, a solution of citric acid (161.52g,
0.769mol) in water (500ml) is added and the mixture is concentrated under reduced
pressure at below 60° C to remove most of the solvent. The resulting aqueous mass
is washed with hexane (2x250ml), basified to pH=9-10 and the product extracted into
ethyl acetate (2x300ml). The ethyl acetate layer is washed with water (200ml) and
degassed to obtain crude product which is purified by flash column chromatography
on silica gel using toluene-methanol (9.3:0.7) as mobile phase to obtain pure product.
Example 9
(R,S)-4-{4-[(4-Chlorophenyl)phenylmethyl]piperazin-1-yl}but-2-yn-1-ol (by method A in Example
8), (Xb, X=Cl; X'=Y=Y'=R1=R2=H; m=1):
[0055] A solution containing
(R,S)-1-[(4-chlorophenyl)phenylmethyl]piperazine (10g, 0.0349mol), toluene (50ml), 4-chloro-2-butyne-1-ol
(4.74g, 0.0453mol), and diisopropylethylamine (9.02g, 0.0698mol) is stirred at 45-50°
C for 6hrs. The reaction mixture is quenched with water (20ml). The organic layer
is separated and the aqueous layer extracted with dichloromethane (2x30ml). The organic
layers is washed with water (20ml) and concentrated to obtain crude product as a syrupy
mass, which is purified by flash column chromatography on silica gel using dichloromethane-methanol
(9.6:0.4) as mobile phase to obtain pure product.
[0056] 1H-NMR (CDCl
3, δppm): 1.88 (br, 1H), 2.20-2.75 (m, 8H), 3.31 (t, J=1.72Hz, 2H), 4.20 (s, 1H), 4.29
(t, J=1.63Hz, 2H), 7.05-7.50 (m, 9H).
Example 10
(R,S)-4-{4-[(4-fluorophenyl)phenylmethyl]piperazin-1-yl}but-2-yn-1-ol (by method B in Example
8), (Xc, X=F; X'=Y=Y'=R1=R2=H; m=1):
[0057] A solution of methanesulfonyl chloride (1.86g, 16.27mmol) and tetrahydrofuran (5ml)
is added dropwise to a stirred solution of 2-butyne-1,4-diol (3.82g, 44.3mmol) and
diisopropylethylamine (6.30g, 48.8mmol) in tetrahydrofuran (20ml) during 30min at
0-5°C. After 1hr stirring the temperature is raised to 25-30°C and stirred for further
1hr. The resulting mixture containing mesylate of 2-butyne-1,4-diol is added dropwise
to a stirred solution of (R,S)-1-[(4-fluorophenyl)phenylmethyl]piperazine (4.0g, 14.79mol)
in tetrahydrofuran (25ml) during 1hr at 5-10°C. The reaction mass is stirred at 5-10°C
for 1hr and then at 25-30° C for further 5hrs. Thereafter, citric acid (3.2g, 0.01523mol)
is added and the mixture is concentrated under reduced pressure at below 60° C to
remove most of the solvent. Water (50ml) is charged to the residual mass and the resulting
aqueous layer washed with hexane (2x30ml), basified to pH=9-10 and the product extracted
into dichloromethane (3x30ml). The dichloromethane layer is washed with water (25ml)
and degassed to obtain crude product as a sticky solid, which is purified by flash
column chromatography on silica gel using dichloromethane-methanol (9.2:0.8) as mobile
phase to obtain pure product as a thick syrupy mass.
[0058] 1H-NMR (CDCl
3, δppm): 1.87 (b), 2.25-2.70 (m, 8H), 3.30 (t, J=1.83Hz, 2H), 4.21 (s, 1H), 4.29 (t,
J=1.78Hz, 2H), 6.85-7.02 (m, 2H), 7.13-7.42 (m, 7H).
Example 11
4-{4-[Bis-(4-fluorophenyl)methyl]piperazin-1-yl}-(E)-but-2-en-1-ol, (XIVa, X=X'=4-F;
Y=Y'=R1=R2=R3=R4=H; m=n=1):
[0059] To a stirred solution of methyl 4-{4-[bis-(4-fluorophenyl)methyl]piperazin-1-yl}-(E)-but-2-enoate
(380 g, 0.984mol) in tetrahydrofuran (1900ml) at -10 to 0° C is added dropwise DIBALH
(560 g, 3.938mol, as 20% solution in toluene) during about 2-3 hrs. After completion
of addition, the reaction mass is stirred for further 1.0 hrs at 0 to 10° C and then
quenched by sequential addition of ethyl acetate (400ml) and water (800ml). After
vigorous stirring for 2 hrs the mass is filtered. The organic layer is separated from
the filtrate, washed with water (1500ml) and concentrated to get crude product.
The crude product is taken in toluene (2000ml), extracted into 10% acetic acid (2000ml),
the aqueous extract basified to pH 9 -10 with 20% aqueous sodium hydroxide and the
product extracted into dichloromethane (3x1500ml). The dichloromethane layer is washed
with water (800ml), and concentrated to get a syrupy mass which is purified by flash
column chromatography on silica gel using toluene-methanol (9:1) as mobile phase.
[0060] 1H-NMR (CDCl
3, δppm): 1.70 (br, D
2O exchangeable), 2.20-2.70 (m, 8H), 3.00 (d, J=5.38Hz, 2H), 4.12 (d, J=4.40Hz, 2H),
4.21 (s, 1H), 5.65-5.90 (m, 2H), 6.85-7.05 (m, 4H), 7.28-7.40 (m, 4H).
Example 12
4-{4-[Bis-(4-fluorophenyl)methyl]piperazin-1-yl}-(E)-but-2-en-1-ol (XIa, X=X'=4-F;
Y=Y'=R1=R2=H; m=1):
[0061] To a stirred solution of 4-{4-[bis-(4-fluorophenyl)methyl]piperazin-1-yl}but-2-yn-1-ol
(135g, 0.379mol) in tetrahydrofuran (4300ml) at 5-10° C is added lithium aluminum
hydride (43.1 g, 1.136mol) in portions during 3-4 hrs. The reaction mixture is stirred
for further 5-6 hrs. and then quenched by addition of ethyl acetate (135ml), followed
by water (100 ml) at 5-10° C. The resulting mixture is filtered, the organic layer
separated from the filtrate, and concentrated to get crude product, which is purified
by flash column chromatography on silica gel using toluene-methanol (9:1) as mobile
phase to obtain pure product.
[0062] 1H-NMR (CDCl
3, δppm): 1.77 (br, D
2O exchangeable), 2.20-2.70 (m, 8H), 3.00 (d, J=4.91Hz, 2H), 4.11 (d, J=3.71Hz, 2H),
4.21 (s, 1H), 5.55-5.90 (m, 2H), 6.80-7.05 (m, 4H), 7.10-7.50 (m, 4H).
Example 13
(R,S)-4-{4-[(4-chlorophenyl)phenylmethyl]piperazin-1-yl}-(E)-but-2-en-1-ol, (XIb, X=Cl;
X'=Y=Y'=R1=R2=H; m=1):
[0063] (R,S)-4-{4-[(4-chlorophenyl)phenylmethyl]piperazin-1-yl}but-2-yn-1-ol (3.5g) is converted
to
(R,S)-4-{4-[(4-chlorophenyl)phenylmethyl]piperazin-1-yl}-(E)-but-2-en-1-ol in a manner
similar to example 12. Crude product is obtained as a syrupy mass, which is purified
by flash column chromatography on silica gel using toluene-methanol (9:1) as mobile
phase to obtain pure product.
[0064] 1H-NMR (CDCl
3, δppm): 2.20-2.65 (m, 8H), 3.00 (d, J=4.83Hz, 2H), 4.11 (d, J=3.52Hz, 2H), 4.20 (s,
1H), 5.60-5.90 (m, 2H), 7.00-7.50 (m, 9H).
Example 12
(R,S)-4-{4-[(4-fluorophenyl)phenylmethyl]piperazin-1-yl}-(E)-but-2-en-1-ol (XIc, X=F; X'=Y=Y'=R1=R2=H;
m=1):
[0065] (R,S)-4-{4-[(4-fluorophenyl)phenylmethyl]piperazin-1-yl}but-2-yn-1-ol (2.13g, 0.0063mol)
is converted to
(R,S)-4-{4-[(4-fluorophenyl)phenylmethyl]piperazin-1-yl}-(E)-but-2-en-1-ol in a manner
similar to example 14. Crude product obtained is obtained as a syrupy mass which is
purified by flash column chromatography on silica gel using dichloromethane-methanol
(9.3:0.7) as mobile phase to obtain pure product.
[0066] 1H-NMR (CDCl
3, δppm): 1.71 (br, exchangeable by D
2O), 2.10-2.70 (m, 8H), 3.00 (d, J=5.23Hz, 2H), 4.11 (d, J=4.20Hz, 2H), 4.22 (s, 2H),
5.65-5.90 (m, 2H), 6.85-7.02 (m, 2H), 7.10-7.45 (m, 7H).
Example 15
Methyl 4-{4-[Bis-(4-fluorophenyl)methyl]piperazin-1-yl}-(E)-but-2-enoate, (XIIIa,
X=X'=4-F; R=CH3; Y=Y'=R1=R2=R3=R4=H; m=n=1):
[0067] A solution of methyl-4-bromocrotonate (46.56g, 0.260mol) in toluene (50ml) is added
dropwise to a mixture containing 1-[bis-(4-fluorophenyl)methyl]piperazine (50g, 0.173mol),
diisopropylethylamine (49.30g, 0.381mol) in toluene (250ml) at 25-30° C during 30
minutes. After stirring for 8hrs, the reaction mass is washed successively with water
(2x150ml), 0.2N hydrochloric acid (3x 150ml), and water (150ml). To the organic layer
at 5-10° C is added 3N hydrochloric acid (200ml), stirred and the aqueous layer containing
product is separated. It is then washed with toluene (200ml), basified to pH = 9-10
with 20% sodium hydroxide solution and the product extracted into ethyl acetate (2x150ml).
The organic layer is washed once with water (100ml), concentrated and degassed. The
residue is triturated with hexane (150ml) and the solid filtered. The product is further
purified by recrystallization from cyclohexane.
[0068] 1H-NMR (CDCl
3, δppm): 1.63 (br, 1H, D
2O exchangeable), 2.20-2.65 (m, 8H), 3.13 (d, J=5.00Hz, 2H), 3.72 (s, 3H), 4.22 (s,
1H), 5.88-6.03 (m, 1H), 6.80-7.05 (m, 5H), 7.20-7.40 (m, 4H).
Example 16
Methyl 4-{4-[(4-chlorophenyl)phenylmethyl]piperazin-1-yl}-(E)-but-2-enoate, (XIIIb,
X=Cl; X'=Y=Y'=R1=R2=R3=R4=H; m=n=1):
[0069] A solution containing
(R,S)-1-[(4-chlorophenyl)phenylmethyl]piperazine (5g, 0.0174mol), DMF (30ml), methyl-4-bromocrotonate
(4.7g, 0.0263mol), and diisopropylethylamine (6.75g, 0.0522mol) is stirred at 27-30°
C for 6hrs. The reaction is quenched with water (40ml) and the product extracted into
dichloromethane (3x30ml). The organic layer is washed with water (2x30ml) and concentrated
to obtain crude product which is purified by flash column chromatography on silica
gel using ethyl acetate-hexane (6.5:3.5) as mobile phase to obtain pure product.
[0070] 1H-NMR (CDCl
3, δppm): 2.20-2.65 (m, 8H), 3.14 (dd, J
1=6.20Hz, J
2=1.39Hz, 2H), 3.72 (s, 3H), 4.20 (s, 1H), 5.85-6.05 (m,1H), 6.8-7.05 (m, 1H), 7.05-7.50
(m, 9H).
Example 17
{4-{4-[Bis-(4-fluorophenyl)methyl]-piperazin-1-yl}-(Z)-but-2-enyloxy}acetic acid dihydrochloride,
(Ia):
[0071] To a stirred solution of 4-{4-[bis-(4-fluorophenyl)methyl]piperazin-1-yl}-(Z)-but-2-en-1-ol
(97.0g, 0.271mol) and potassium tert-butoxide (54.7g, 0.487mol) in anhydrous tert-butanol
(776ml), preheated at 60-65° C for 1 hr., under nitrogen atmosphere, is added dry
sodium chloroacetate (63g, 0.541mol). The reaction mass is then refluxed for further
5hrs. The mixture is then concentrated under reduced pressure at below 60° C until
tert-butanol is completely removed. The residue is taken up in water (800ml) and washed
with ethyl acetate (2x500ml). The aqueous solution is then acidified to pH 5-6, extracted
into dichloromethane (3x500ml), washed dichloromethane layer with water (300ml), and
concentrated to get crude product, whuch is purified by flash column chromatography
on silica gel using toluene-methanol (4:1) as mobile phase to obtain pure product.
[0072] 1H-NMR (CDCl
3, δppm): 2.40-2.80 (m, 4H), 2.80-3.20 (m, 4H), 3.65 (d, J=7.51Hz, 2H), 3.96 (s, 2H),
4.19 (d, J=4.51Hz, 2H), 4.32 (s, 1H), 5.00-5.30 (m, 1H), 5.30-6.10 (m, 1H), 6.80-7.05
(m, 4H), 7.00-7.50 (m, 4H)
[0073] A suspension of {4-[4-[bis-(4-fluorophenyl)methyl]piperizin-1-yl]-(Z)-but-2-enyloxy}acetic
acid (83.8g, 0.201mol) and water (335ml) is acidified under stirring to pH 1-2 with
6N hydrochloric acid at 25-30°C. The solution is filtered, concentrated under reduced
pressure at below 50° C (until volume of solution is around 170ml), and lyophilized
to obtain the dihydrochloride salt.
Example 18
(R,S)-{4-[4-[(4-Chlorophenyl)phenylmethyl]piperazin-1-yl]-(Z)-but-2-enyloxy}acetic acid
dihydrochloride, [Ib (R,S)]:
[0074] (R,S)-4-{4-[(4-chlorophenyl)phenylmethyl]piperazin-1-yl}-(Z)-but-2-en-1-ol (100.0g, 0.28mol)
is converted to
(R,S)-{4-[4-[(4-chlorophenyl)phenylmethyl]piperazin-1-yl]-(Z)-but-2-enyloxy} acetic acid
in a manner similar to example 19. Crude product is obtained is as a foamy solid which
is purified by flash column chromatography on silica gel using toluene-methanol (4:1)
as mobile phase to obtain pure product.
[0075] 1H-NMR (CDCl
3, δppm): 2.40-2.75 (m, 4H), 2.75-3.20 (m, 4H), 3.62 (d, J=7.43Hz, 2H), 3.95 (s, 2H),
4.17 (d, J= 4.9Hz, 2H), 4.28 (s, 1H), 5.50-5.80 (m, 1H), 5.80-6.1 (m, 1H), 6.95-7.40
(m, 9H), 8.98 (br, exchangeable with D
2O)
[0076] It was converted to dihydrochloride salt as per example 17.
Example 19
[4-(4-Benzhydrylpiperazin-1-yl)-(Z)-but-2-enyloxy]acetic acid dihydrochloride, (Ic):
[0077] 4-(4-Benzhydrylpiperazin-1-yl)-(Z)-but-2-en-1-ol (2.1g, 0.0065mol) is converted to
[4-(4-benzhydrylpiperazin-1-yl)-(Z)-but-2-enyloxy]acetic acid in a manner similar
to example 17. The crude product obtained as a foamy solid is purified by flash column
chromatography on silica gel using toluene-methanol (8.5:1.5) as mobile phase to obtain
pure product.
[0078] 1H-NMR (CDCl
3, δppm): 2.40-2.85 (m, 4H), 2.85-3.20 (m, 4H), 3.68 (d, J=7.53Hz, 2H), 3.96 (s, 2H),
4.18 (d, J= 4.60Hz, 2H), 4.33 (s, 1H), 5.50-5.80 (m, 1H), 5.90-6.10 (m, 1H), 7.00-7.50
(m, 10H)
[0079] It is converted to dihydrochloride salt as per example 19.
Example 20
{4-{4-[Bis-(2,4-difluorophenyl)methyl]-piperazin-1-yl}-(Z)-but-2-enyloxy}acetic acid
dihydrochloride, (Id):
[0080] 4-{4-[Bis-(2,4-difluorophenyl)methyl]piperazin-1-yl}-(Z)-but-2-en-1-ol (6.2g, 0.0157mol)
is converted {4-{4-[bis-(2,4-difluorophenyl)methyl]-piperazin-1-yl}-(Z)-but-2-enyloxy}acetic
acid in a manner similar to example 17. Crude product is obtained is as a foamy solid
which is purified by flash column chromatography on silica gel using toluene-methanol
(4:1) as mobile phase to obtain pure product.
[0081] 1H-NMR (CDCl
3, δppm): 2.20-2.75 (m, 4H), 2.75-3.20 (m, 4H), 3.57 (d, J=6.07Hz, 2H), 3.96 (s, 2H),
4.17 (d, J=3.90Hz, 2H), 4.99 (s, 1H), 5.50-6.10 (m, 2H), 6.45-7.0 (m, 4H), 7.20-7.65
(m, 2H), 9.87 (br)
[0082] The product is taken up in ethyl acetate (12ml), acidified with a solution of anhydrous
HCl in ethyl acetate to pH 1.0 to 2.0, concentrated and degassed to get the dihydrochloride
salt.
Example 21
{4-[4-[Bis-(4-chlorophenyl)methyl]-piperazin-1-yl]-(Z)-but-2-enyloxy}acetic acid dihydrochloride,
(Ie):
[0083] 4-{4-[Bis-(4-chlorophenyl)methyl]piperazin-l-y}-(Z)-but-2-en-1-ol (2.26g, mol) is
converted to {4-[4-[bis-(4-chlorophenyl)methyl]-piperazin-1-yl]-(Z)-but-2-enyloxy}acetic
acid in a manner similar to example 17. Crude product obtained is purified by flash
column chromatography on silica gel using toluene-methanol (4:1) as mobile phase to
obtain pure product.
[0084] 1H-NMR (CDCl
3, δppm): 2.50-2.80 (m, 4H), 2.80-3.20 (m, 4H), 3.60 (d, J=7.38Hz, 2H), 3.94 (s, 2H),
4.20 (d, J=4.08Hz, 2H), 4.31 (s, 1H), 5.23 (br, exchangeable with D
2O), 5.50-5.80 (m, 1H), 5.80-6.10 (m, 1H), 7.10-7.40 (m, 8H).
The product was converted to dihydrochloride salt as in example 17.
Example 22
{4-{4-[Bis-(4-fluorophenyl)methyl]-piperazin-1-yl}-(Z)-but-2-enyloxy}acetic acid methyl
ester dihydrochloride, (If):
[0085] To a stirred solution of {4-{4-[bis-(4-fluorophenyl)methyl]-piperazin-1-yl}-(Z)-but-2-enyloxy}acetic
acid (35g, 0.084mol) in methanol (560ml), is added a solution of anhydrous HCl in
ethyl acetate till pH is 1-2. The solution is refluxed for 2hrs, cooled to 25-30°
C and stirred for 4hrs. The crystallized solid is filtered, washed with ethyl acetate
(2x5ml), and dried in oven at 60-65° C to get the product.
[0086] 1H-NMR (D
2O, δppm): 3.20-3.60 (m, 8H), 3.64 (s, 3H), 3.94 (d, J=7.66Hz, 2H), 4.00-4.20 (m, 4H),
5.31 (s, 1H), 5.50-5.78 (m, 1H), 5.90-6.20 (m, 1H), 6.85-7.15 (m, 4H), 7.30-7.60 (m,
4H).
Example 23
{4-{4-[Bis-(4-fluorophenyl)methyl]-piperazin-1-yl}-(Z)-but-2-enyloxy}acetic acid ethyl
ester dihydrochloride, (Ig):
[0087] To a stirred solution of {4-{4-[bis-(4-fluorophenyl)methyl]-piperazin-1-yl}-(Z)-but-2-enyloxy}acetic
acid (1.0g, 0.0024mol) in ethanol (20ml), is added a solution of anhydrous ethanolic
HCl till pH is 1-2. The solution is refluxed for around 2hrs, cooled to 25-30°C and
stirred for 4hrs. The crystallized solid is filtered, washed with ethanol (2x5ml),
and dried in oven at 60-65° C to get the product.
[0088] 1H-NMR (CDCl
3+DMSO-d
6, δppm): 1.28 (t, J=7.10Hz, 3H), 2.70-4.30 (m, 17H), 5.70-6.20 (m, 2H), 7.10 (t, J=8.62Hz,
4H), 7.40-7.80 (m, 4H).
Example 24
{4-{4-[Bis-(4-fluorophenyl)methyl]-piperazin-1-yl}-(Z)-but-2-enyloxy}acetic acid isopropyl
ester dihydrochloride, (Ih):
[0089] To a stirred solution of {4-{4-[bis-(4-fluorophenyl)methyl]piperazin-1-yl}-(Z)-but-2-enyloxy}acetic
acid (1.0g, 0.0024mol) in isopropyl alcohol (20ml), is added a solution of anhydrous
HCl in isopropyl alcohol till pH of solution is 1-2. The solution is refluxed for
around 2hrs, cooled to 25-30°C and stirred for 4hrs. The crystallized solid is filtered,
washed with isopropyl alcohol (2x5ml), and dried in oven at 60-65°C to get product
0.968g (75.85% yield).
[0090] 1H-NMR (CDCl
3+DMSO-d
6, δppm): 1.23 (d, J=6.25Hz, 6H), 2.60-3.70 (m, 8H), 3.70-4.40 (m, 7H), 4.80-5.20 (m,
1H), 5.60-5.90 (m, 1H), 5.90-6.10 (m, 1H), 7.16 (t, J=8.56Hz, 4H), 7.40-7.90 (m, 4H).
Example 25
(R,S)-{4-[4-[(4-chlorophenyl)phenylmethyl]piperazin-1-yl]-(Z)-but-2-enyloxy}acetic
acid isopropyl ester dihydrochloride, (Ii):
[0091] The preparation was carried out using (R,S)-{4-[4-[(4-chlorophenyl)phenylmethyl]piperazin-1-yl]-(Z)-but-2-enyloxy}acetic
acid in a manner similar to example 24.
[0092] 1H-NMR (CDCl
3+DMSO-d
6, δppm): 1.26 (d, J=6.26Hz, 6H), 2.80-3.70 (m, 8H), 3.80-4.15 (m, 3H), 4.21 (d, J=5.57Hz,
4H), 4.90-5.15 (m, 1H), 5.70-5.95 (m, 1H), 5.95-6.15 (m, 1H), 7.10-7.90 (m, 9H).
Example 26
(R,S)-{4-[4-[(4-chlorophenyl)phenylmethyl]piperazin-1-yl]-(Z)-but-2-enyloxy}acetic
acid methyl ester dihydrochloride, (Ij):
[0093] To a stirred solution of (R,S)-{4-[4-[(4-chlorophenyl)phenylmethyl]piperazin-1-yl]-(Z)-but-2-enyloxy}acetic
acid (1g, 0.0024mol) in methanol (20ml), is added a solution of anhydrous HCl in ethyl
acetate till pH of the solution is 1-2. The solution is refluxed for 2hrs, cooled
to 25-30°C, added anhydrous diethyl ether till slight haziness and stirred for 4hrs.
The crystallized solid is filtered, washed with diethyl ether (2x5ml), and dried in
oven at 60-65°C to get product.
[0094] 1H-NMR (CDCl
3+DMSO-d
6, δppm): 3.10-3.90 (m, 8H), 3.73 (s, 3H), 3.90-4.30 (m, 7H), 5.70-6.00 (m, 1H), 6.00-6.20
(m, 1H), 7.10-7.50 (m, 5H), 7.50-8.00 (m, 4H).
Example 27
(R,S)-{4-[4-[(4-chlorophenyl)phenylmethyl]piperazin-1-yl]-(Z)-but-2-enyloxy}acetic
acid ethyl ester dihydrochloride, (Ik):
[0095] The preparation was carried out using (R,S)-{4-[4-[(4-chlorophenyl)phenylmethyl]piperazin-1-yl]-(Z)-but-2-enyloxy}
acetic acid in a manner similar to example 25, to obtain the product.
[0096] 1H-NMR (CDCl
3+DMSO-d
6, δppm): 1.27 (t, J=7.12Hz, 3H), 3.10-3.90 (m, 8H), 3.90-4.30 (m, 9H), 5.75-5.95 (m,
1H), 5.95-6.15 (m, 1H), 7.10-7.50 (m, 5H), 7.50-8.00 (m, 4H).
Example 28
{2-{4-[bis-(4-fluorophenyl)methyl]piperazin-1-ylmethyl}benzyloxy}acetic acid dihydrochloride,
(IIa):
[0097] {2-{4-[Bis-(4-fluorophenyl)methyl]piperazin-1-ylmethyl}phenyl}methanol (5.0g, 0.0122mol)
is converted to {2-{4-[Bis-(4-fluorophenyl)methyl]piperazin-1-ylmethyl}benzyloxy}acetic
acid in a manner similar to example 17. Crude product obtained is purified by flash
column chromatography on silica gel using toluene-methanol (8.5:1.5) as mobile phase
to obtain pure product as a white foamy solid.
[0098] 1H-NMR (CDCl
3, δppm): 2.40-2.75 (m, 4H), 2.75-3.20 (m, 4H), 4.06 (s, 2H), 4.10 (s, 2H), 4.28 (s,
1H), 4.58 (s, 2H), 6.70-7.10 (m, 4H), 7.10-7.50 (m, 8H).
[0099] The product is taken up in ethyl acetate (12ml), acidified with a solution of anhydrous
HCl in ethyl acetate to pH 1.0 to 2.0, concentrated and degassed to get dihydrochloride
salt as a white solid.
Example 29
(R,S) {2-{4-[(4-chlorophenyl)phenylmethyl]piperazin-1-ylmethyl}benzyloxy} acetic acid
dihydrochloride, (IIb):
[0100] {2-{4-[(4-chlorophenyl)phenylmethyl]piperazin-1-ylmethyl}phenyl}methanol (4.0g, 9.83mmol)
is converted to {2-{4-[(4-chlorophenyl)phenylmethyl]piperazin-1-ylmethyl}benzyloxy}acetic
acid in a manner similar to example 17. Crude product obtained as an off-white foamy
solid is purified by flash column chromatography on silica gel using toluene-methanol
(8.5:1.5) as mobile phase to obtain pure product as a white foamy solid.
[0101] 1H-NMR (CDCl
3, δppm): 2.40-2.80 (m, 4H), 2.80-3.20 (m, 4H), 4.06 (s, 2H), 4.14 (s, 2H), 4.28 (s,
1H), 4.58 (s, 2H), 7.00-7.50 (m, 13H).
[0102] The product is converted to dihydrochloride salt using a solution of anhydrous HCl
in ethyl acetate as in example 28.
Example 30
{4-[4-[Bis-(4-fluorophenyl)methyl]piperizin-1-yl]-(E)-but-2-enyloxy}acetic acid dihydrochloride,
(IIIa):
[0103] To a stirred solution of 4-{4-[bis-(4-fluorophenyl)methyl]piperazin-1-yl}-(E)-but-2-en-1-ol
(247.0g, 0.689mol) and potassium tert-butoxide (139.2g, 1.240mol) in anhydrous tert-butanol
(2000ml), preheated at 60-65° C for 1 hr. under nitrogen atmosphere, is added dry
sodium chloroacetate (160.5g, 1.378mol). The reaction mass is then refluxed for further
5hrs. The mixture is then concentrated under reduced pressure at below 60° C until
tert-butanol is completely removed. The residue is taken up in water (1500ml) and
washed with ethyl acetate (2 x 1500ml). The aqueous solution is then acidified to
pH 5-6, extracted into dichloromethane (2 x 750ml), washed dichloromethane layer with
water (300ml), and concentrated to get crude product as a foamy solid. The crude product
is purified by flash column chromatography on silica gel using toluene-methanol (4:1)
as mobile phase. The product was converted to its dihydrochloride salt as in example
17.
[0104] 1H-NMR (D
2O, δppm): 3.20-3.70 (m, 8H), 3.82 (d, J=6.79Hz, 2H), 3.93-4.05 (m, 4H), 5.35 (s, 1H),
5.65-5.80 (m, 1H), 5.97-6.12 (m, 1H), 6.80-7.00 (m, 4H), 7.36-7.50 (m, 4H).
Example 31
(R,S)-{4-[4-[(4-Chlorophenyl)phenylmethyl]piperizin-1-yl]-(E)-but-2-enyloxy}acetic
acid dihydrochloride, (IIIb):
[0105] (R,S)-4-{4-[(4-Chlorophenyl)phenylmethyl]piperazin-1-yl}-(E)-but-2-en-1-ol (1.9g,
0.0053mol) is converted to (R,S)-{4-[4-[(4-Chlorophenyl)phenylmethyl]piperizin-1-yl]-(E)-but-2-enyloxy}
acetic acid as in example 30. Crude product is obtained as a foamy solid which is
purified by flash column chromatography on silica gel using toluene-methanol (8:2)
as mobile phase to obtain pure product.
[0106] 1H-NMR (CDCl
3, δppm): 2.40-2.75 (m, 4H), 2.75-3.20 (m, 4H), 3.30-3.50 (m, 2H), 3.93 (s, 2H), 4.00-4.15
(m, 2H), 4.26 (s, 1H), 5.70-6.00 (m, 2H), 6.82 (br), 7.00-7.50 (m, 9H)
[0107] It was converted to dihydrochloride salt as per example 17.
Example 32
(R,S)-{4-[4-[(4-fluorophenyl)phenylmethyl]piperazin-1-yl]-(E)-but-2-enyloxy} acetic
acid dihydrochloride, (IIIc):
[0108] (R,S)-4-{4-[(4-Fluorophenyl)phenylmethyl]piperazin-1-yl}-(E)-but-2-en-1-ol (0.7g,
2.06mmol) is converted to (R,S)-{4-[4-[(4-fluorophenyl)phenylmethyl]piperizin-1-yl]-(E)-but-2-enyloxy}acetic
acid as per example 30. The crude product obtained (0.77g) is purified by flash column
chromatography on silica gel using toluene-methanol (3:2) as mobile phase to obtain
pure product.
[0109] 1H-NMR (CDCl
3, δppm): 2.40-3.20 (m, 8H), 3.20-3.50 (m, 2H), 3.92 (s, 2H), 4.00-4.15 (m, 2H), 4.26
(s, 1H), 5.65-5.95 (m, 2H), 6.80-7.03 (m, 2H), 7.07-7.50 (m, 7H), 10.70 (br, exchangeable).
[0110] It is converted to its dihydrochloride salt as in example 17.
IC50 determination using isolated guinea pig ileum functional assay
[0111] Terminal segment of ileum of junction of Dunken Hartley guinea pig, of about 10 cm
from the ileo-caecal, separated from mesenteric attachments was immediately removed
and placed in Tyrode solution of composition, NaCl 137.0mM, KCl 2.7 mM, CaCl
2 1.8 mM, MgCl
2 1.05 mM, NaHCO
3 11.9 mM, NaH
2PO
4 0.42 mM and glucose 5.6 mM, maintained at 35° C.
The lumen of the ileum was gently cleaned with Tyrode so as to remove any particle
without affecting the mucosal layer of the tissue. Pieces of 1.5-2 .0 cm length were
cut and placed in the organ bath of 20ml capacity, attaching one end to the tissue
holder and other to the transducer by a fine cotton thread. The system was previously
calibrated before start of each experiment. Tissue was kept under a resting tension
of 0.5-0.75g. The bath solution was continuously bubbled with 95 % O
2 and 5% CO
2 and maintained at 35° C temperature. After an initial 30 min of equilibration time
the baseline was recorded and non-cumulative responses with sub maximal dose of histamine
(7.2 X 10
-7M) were initially recorded until the responses were reproducible. The contractions
to this typical dose of histamine in absence (only vehicle) and presence of at least
3 different concentrations of the test compounds were recorded after 15min constant
incubation time. The percentage inhibitions caused by different concentrations of
test compounds were plotted against the log of molar concentrations of the test compounds
for the determination of IC
50.
TABLE-1
| The compound of formula I is tested for its activity in its hydrochloride salt form |
| Comp d. |
X |
Y |
X' |
Y' |
R1 |
R2 |
R3 |
R4 |
m |
n |
Z |
IC50 (mean) ± SEM
(moles) |
| Ia |
4-F |
H |
4-F |
H |
H |
H |
H |
H |
1 |
1 |
OH |
2.17 x 10-6 ± 4.23 x 10-7 |
| Ib |
4-Cl |
H |
H |
H |
H |
H |
H |
H |
1 |
1 |
OH |
2.13 X 10-7 ± 5.37 X 10-8 |
| Ic |
H |
H |
H |
H |
H |
H |
H |
H |
1 |
1 |
OH |
1.30 x 10-6 ± 4.17 x 10-7 |
| Id |
2-F |
4-F |
2-F |
4-F |
H |
H |
H |
H |
1 |
1 |
OH |
2.26 x 10-6 ± 5.37 x 10-7 |
| Ie |
4-Cl |
H |
4-Cl |
H |
H |
H |
H |
H |
1 |
1 |
OH |
3.27 X 10-7 ± 3.59 X 10-7 |
| If |
4-F |
H |
4-F |
H |
H |
H |
H |
H |
1 |
1 |
OCH3 |
4.00 x 10-7 ± 2.91 x 10-7 |
| Ig |
4-F |
H |
4-F |
H |
H |
H |
H |
H |
1 |
1 |
OC2H5 |
4.09 x 10-7 ± 3.39 x 10-8 |
| Ih |
4-F |
H |
4-F |
H |
H |
H |
H |
H |
1 |
1 |
OisoPr |
4.66 x 10-7 ± 1.20 x 10-8 |
| Ii |
4-Cl |
H |
H |
H |
H |
H |
H |
H |
1 |
1 |
OisoPr |
2.37 x 10-7 ± 3.54 x 10-9 |
| Ij |
4-Cl |
H |
H |
H |
H |
H |
H |
H |
1 |
1 |
OCH3 |
4.66 x 10-7 ± 3.54 x 10-8 |
| Ik |
4-Cl |
H |
H |
H |
H |
H |
H |
H |
1 |
1 |
OC2H5 |
7.35 x 10-7 ± 1.85 x 10-7 |
| IIa |
4-F |
H |
4-F |
H |
H |
H |
Part of benzene ring |
1 |
1 |
OH |
1.19 X 10-6 ± 7.01 X 10-7 |
| IIb |
4-Cl |
H |
H |
H |
H |
H |
Part of benzene ring |
1 |
1 |
OH |
5.64 X 10-7 ± 1.91 X 10-8 |
| IIIa |
4-F |
H |
4-F |
H |
H |
H |
H |
H |
1 |
1 |
OH |
4.72 x 10-6 ± 5.90 x 10-6 |
| IIIb |
4-Cl |
H |
H |
H |
H |
H |
H |
H |
1 |
1 |
OH |
3.93 x 10-7 ± 1.84 x 10-7 |
| IIIc |
4-F |
H |
H |
H |
H |
H |
H |
H |
1 |
1 |
OH |
8.77 x 10-7 + 5.13 x 10-7 |
| Cetiri zine |
|
|
|
|
|
|
|
|
|
|
|
3.16 x 10-6 ± 4.09 x 10-6 |