AU619049B2 - New 1,4-dihydropyridinederivative, namely (-)-2-{(2- aminoethoxy) ethoxy)-4-(2,3-dichlorophenyl)-3- ethoxycarbonyl-50methoxycarbonyl-6-methyl}-1,4- dihydropyridine, process for preparing it and pharmaceutical compositions containing it - Google Patents

Abstract

(-)2{[2-(2-Aminoethoxy)ethoxy]methyl}-4-(2,3-dichlorophenyl)-3-etho xycarbonyl-5-methoxycarbonyl-6-methyl-1,4-dihydropyridine compound of formula I <IMAGE> and its addition salts with a pharmaceutically acceptable inorganic or organic acid. Medication.

Description

COMMONWEALTH OF AUSTRALIA PATENTS ACT 1952-69 COMPLETE SPECIFICATION

(ORIGINAL)

Class Application Number: Lodged: Form Int. Class 0Complete Specification Lodged: 090 Accepted: 00 Published: 0 0 Re.ated Art: I'larpie of Applicant: cAddress of Applicant: a 0 Actual Inventor: SAfd'ress for Service: ADIR ET CCO4PAGNIE 22 Rue Gamnier, 9200 Neuilly-sur-Seine. France.

JEAN-LOUIS PEGLION, YVES-MICHEL GARGOUIL and JEAN-PAUL VILAINE EDWD. WATERS SONS, 50 QUEEN STREET, MELBOURNE, AUSTRALIA, 3000.

Complete Specification for the invention entitled: NEW 1, 4-DI-YDROPYRIDINE DERIVATIVE, NAMELY 112- (-AMINOETOXY) ETHOXY-4- 3-DICHLlROPHENYL )-3-EHOXYCARBONYL-5-MEEHOXYCA1RBONYL-6-METHYI 1 ,4- DII-1YDROPYRIDINE, PROCESS FOR PREPARING IT AND PHARMACUTICAL~ COMPOSITIONS CONTAINING IT.

The following statement is a full description of this invention, including the best method of performing it known to la- The present invention relates to a new 1,4dihydropyridine derivative, (-)-2-{[2-(2-aminoethoxy)ethoxy]methy:l}-4-(2,3-dichlorophenyl)-3-ethoxycarbonyl- 5-methoxycarbonyl-6-methyl-l,4-dihydropyridine, to a process for preparing it and to pharmaceutical compositions containing it.

Some 1,4-dihydropyridine derivatives possessing advantageous pharmacological properties have been described in Patent EP 259,206. This patent describes and claims, among a large number of compounds, aminoethoxy)ethoxy]methyl}-4-(2,3-dichlorophenyl)-3ethoxycarbonyl-5-methoxycarbonyl-6-methyl-l,4-dihydropyridine. The process for obtaining this compound in its racemic form is exemplified in this patent.

In the light of the very advantageous therapeutic results obtained on this product, research in greater depth was undertaken in order to separate the optical isomers of the compound, and led to the discovery of 2-{[2-(2-aminoethoxy)ethoxy]methyl}-4-(2,3-dichlorophenyl)-3-ethoxycarbonyl-5-methoxycarbonyl-6-methyl-l,4dihydropyridine.

In effect, the different processes of separation of isomers or of stereoselective synthesis described in the literature do not enable the isomers of aminoethoxy)ethoxy]methyl}-4-(2,3-dichlorophenyl)-3ethoxycarbonyl-5-methoxycarbonyl-6-methyl-1,4-dihydropyridine to be obtained. It was hence necessary to invent a new process, which also forms the subject of the present invention.

2 -{[2-(2-Aminoethoxy)ethoxy]methyl}-4-(2,3dichlorophenyl)-3-ethoxycarbonyl-5-methoxycarbonyl-6methyl-1,4-dihydropyridine is a potent inhibitor of the intracellular penetration of calcium.

Theoretically, the active isomer of a compound endowed with pharmacological properties possesses not more than twice the activity of the racemate.

In the present case, pharmacological tests demonstrated that the activity of the compound of the invention is very much greater.

I'In -2- The subject of the present invention is, more 3-dichiorophenyl) 6-methyl-1,4-dihydropyridine, the compound of formula I: C1 0 CI0 3 C-0-C ~-C-0-CH 2

CH

3 (I

H

3 C N H CH 2 -0-C H 2 C H 2 -O0-CH 2 C H 2 N H 2 and its addition salts with ja pharmaceutically acceptable inorganic or organic acid.

Among acids used, fuinaric, tartaric, camphorsulfonic, hydrochloric, citric, methanesulfonic and benzene- 10 sulfonic acids, and the like, may be mentioned.

Th subject of the present invention is also the process for preparing the compound of formula I, wherein 2-[2-(2-chloroethoxy)ethoxy]ethano1 is condensed with potassium phthalimide, in dimethylformamide in :the 148atd stats, to form 2-[2-(2-phthalimidoethoxy)ethoxy]ethanol, the compound of formula II 0 Q N-CH2CH 2

OCH

2

CH

2 0CH 2

CH

2 OH (I which is converted by meansof Jones rea~entAto 2-2(2 phtaliidothoy) thoy) cetc aidthecompound of formula III: 0 1N-CH2CH 2

OCH

2 CH20CH2COOH

I)

-3 which is treated with carbonyldiimidazole and Meldruxn's acid in the presence of pyridine in* methylene chloride/,to obtain the compound of formula IV: o 0

CH

3 0- 01 x/-C-CH 2

OCH

2

CH

2

OCH

2

CH

2

-NQ(J)

CH

3 0 o 0 which is the~ react dwith -2-phenyl-2-methoxyethanol, the compound of formula V:

(R)

CH-CH

2 0H(V

OC-H

3 to obtain the fl-keto ester of formula VI: 0 0 0 OCH 3

(I

N.CH2CH2OCH2CH 2 0CH 2 .C-CH2-CQOCH 2 .CH 0

(R)

0 which s 4 condensed in the presence of ammonium formate in ethanolAwith a benzylidene compound of formula VII: A Ci(VII)

CH

3 00C

-~H

H

3 C0H to obtain (4R,4'R/4S,4'R)-4-(2,3-dichlorophenyi)-5methoxycarbonyi-3- (2-methoxy-2-phenylethoxycarbonyl) -6methyl-2-{(2-(2-phthalimidoethoxy)ethoxy]methyl}-1,4dihydropyridine, the compound of formula VIII: -4

CH

3 00C C

CH

3 N 2

CH

H I CH 2

OCH

2

CH

2

OCH

2

CH

2 N0 and then: (4RI4 4'R)

U

either: this compound is subjected to the action of aqlo~ sodium bicarbonate solution, in solution in acetonitrileA to obtain (4R,4'R/4S,4'R)-2-t{2-lI2-(2-carboxyphenylcarboxainido )ethoxylIethoxylmethyl 3-dichiorophenyl) 5-methoxycarbonyl-3-( 2-methoxy-2-phenylethoxycarbolyl)- 6-methyl-l,4-dihydropyridine, the compound of formula IX: C1 00

CH

3 00C Cl 0 9 OCH 3

CO

CH

3 N CH 2

OCH

2

CH

2 OCH2CH2NH-C- Q H 0 (4R,4 R/4S,4-R) which is treated, after separation by H{PLC, with a o mixture of glyme and sodium ethylate to obtain a mixture 0 0,containing (---f-2(-abryhnlabxmd) ethoxy) ethoxylmethyl 1-4- 3-dichioropheflyl) -3-ethoxyearbonyl1-imethoxyea-rb~rnyl-6--methyl-l 1, 4.dihydropyridine~ the compound of formula X:

T

CI'

I

CH

3 00C CH3 N

COOC

2

H

5 COOH

CH

2 0CH 2

CH

2 0CH 2

CH

2 N H-CQ 0 and its homolog substituted at the 5-position with an ethoxycarbonyl radical, or: the compound of formula VIII is separated by chromatography on a silica column, using a mixture of methylene #tot chloride and ethyl acetate (95:5 V/V) as eluant, to #tot obtain the less polar isomer of 4-(2,3-dichlorophenyl)- 5-methoxycarbonyl-3-( 2-methoxy-2-phenylethoxycarbonyl) j 1 >10 6-methyl-2-{[2-(2-phthalimidoethoxy)ethoxy]methyl}-1,4dihydropyridine h i s then subjected to the action of sodium etaoaente presence of glyme in solution in ethanol to obtain a mixture containing the compound of formula X and its homolog substituted at the with an ethoxycarbonyl radical, which is then subjected to the action of carbonyldiimidazole in solution in a halogenated alkane at room temperature to obtain a mixture containing 2,3-dichlorophenyl) -3-ethoxycarbonyl-5-methoxycarbonyl-6-methyl-2-{ 2-phthalimidoethoxy)ethoxy]methyl}-1 1 4-dihydropyridine, the compound of formula XI:

I

I

I

Ii ~4.

IL

C I

CH

3 00C, CH3

(XI)

2 0CH and its homolog substituted at the 5-position with an ethoxycarbonyl radical, which mixture is then separated I 1 6 toa o a 0d a by HPLC to obtain pure (-)-4-(2,3-dichlorophenyl)-3ethoxycarbonyl-5-methoxycarbonyl-6-methyl-2-{[2-(2phthalimidoethoxy)ethoxy]methyl}-1,4-dihydropyridine, which is then brought to reflux in ethanol in the presence of hydrazine hydrate to give the compound of formula I, which can then be salified with a pharmaceutically compatible organic or inorganic acid.

(R)-2-Phenyl-2-methoxyethanol, the compound of formula V, is obtained by reduction of the optically active corresponding acid. The latter compound is prepared according to the process described in J. Chem.

Soc., 1962, p.

1519 2-(2,3-Dichlorobenzylidene)-3-oxobutanoic acid methyl ester, the compound of formula VII, is obtained by 15 condensation of 2,3-dichlorobenzaldehyde with methyl acetoacetate.

The compound of formula I is a markedly more potent inhibitor of the intracellular penetration of calcium than its corresponding racemate. In effect, surprisingly, the results of pharmacological tests demonstrated that the compound of formula I possesses an activity which is 4 to 30 times as great as the activity of the racemate.

The intracellular calcium concentration plays the part of a messenger for many biological functions: contractions, secretions; this concentration depends greatly on the transmembrane penetration of calcium which, highly concentrated in the extracellular media, travels through calcium-selective channels located in the 30 membrane.

Thus, inhibitors of these channels which limit or abolish calcium penetration can have advantageous therapeutic effects in a number of pathological conditions, such as, for example, vasorelaxation for the treatment of arterial hypertension and pulmonary hypertension and peripheral and coronary vascular diseases (Am. J. Card.

1980, 46, p.1047-1058; Burger's Medicinal Chemistry 4th edition, part III, p.

545 6 John Wiley and Sons Inc. USA, 1981; Life Sciences, 1983, 33, p.2571- 2 581). Induced 6 00 4 4 I' .v-^M UI~I~"~~~P~~~LI~II-rri 7 o 0 o 0 0o 0 0 0 00 0 00 0 beneficial effects are also observed for the treatment of heart failure A reduction of myocardial contraction is also useful in cardiac ischemic situations (Medicine, 1985, 64, p.

6 1- 73 Limitation of the penetration of calcium into cells can also play an important part in preventing the calcium accumulation characteristic of cell aging, and linked to certain vascular degenerative diseases, especially atheroma (Medicinal Research Review, 1985, p.394-425).

Calcium modulation is also of importance for the treatment of epilepsy and of dizziness of central origin.

Limitation of ionized calcium in the smooth fibers of the walls of the digestive tract also permits relief of esophageal spasms, and at pulmonary level that of bronchial spasm (treatment of asthma). This reduction of calcium can also be useful as an adjuvant in the treatment of cancer and of hypercoagulation.

The present description is not, moreover, limiting; basic research stresses the part played by calcium as being of the first importance in numerous physiological and physiopathological phenomena.

Pharmacological trials in rats showed that, in vivo, the activity of the compound of the invention is greater than that of its racemate and that it is endowed with a longer-lasting action, and confirm the importance of its use in therapy.

The invention also encompasses the pharmaceutical compositions containing, as active. principal, the compound of formula I, or one of its addition salts with an inorganic or organic acid, with one or more suitable nontoxic, inert excipients.

The pharmaceutical compositions thereby obtained are advantageously presented in various forms such as, for example, tablets, dragees, hard gelatin capsules, sublingual tablets or other suitable dosage forms.

The pharmaceutical compositions according to the invention can contain, in addition, an active principle having a complementary or synergistic action.

0 00 0 0 o o o e o 00 1 I 8 The dosage can vary widely depending on the patient's age and weight and the nature and severity of the condition, as well as on the administration route, oral or parenteral. Generally speaking, the unit dosage will range between 0.02 and 50 mg and the daily dosage administered orally, usable in human or animal therapy, between 0.02 and 100 mg.

The examples which follow, given without implied Slimitation, illustrate the invention.

The stated melting points are measured according to the micro-Kofler technique.

The proton nuclear magnetic resonance (NMR) spectra were recorded at 200 MHz.

EXAMPLE 1 2-r2-(2-Phthalimidoethoxyethoxy]acetic acid STAGE A 2-[2-(2-Phthalimidoethoxy)ethoxy]ethanol 188 g of 2-[2-(2-chloroethoxy)ethoxy]ethanol and I 146 g of potassium phthalimide in 700 ml of dimethylformamide are brought to 95 0 C for 17 hours.

The mixture is diluted with methylene chloride, washed with saturated sodium chloride solution, dried and evaporated.

It is distilled in a Kugelrohr, b.p..

05 n 180h P b. 05 imnHg 185 0

C.

Yield: Proton nuclear magnetic resonance spectrum (Solvent CDCl 30 4H(m) 7.5 to 8 ppm; 12H(m) 3.4 to 4 ppm; 1H (complex -at exchangeable D O) 2.5 to 3 ppm.

STAGE B 3 g of the alcohol obtained in the preceding stage are dissolved in 150 ml of acetone. Jones reagent is introduced while the temperature is maintained at between 20 and 25'C. The mixture is left to stand for 1 hour at room temperature. It is concentrated, then diluted with methylene chloride and washed with water. It is dried and the solvent is evaporated off to obtain the i 1 -9 expected compound.

Melting point: 88-90*C Yield: Proton nuclear magnetic resonance spectrum (Solvent CDC11 1H (complex exchangeable) 8.8 to 9.5 ppm; 4H(m) 7.6 to 8.1 ppm; 2H(s) 4.1 ppm; 8H(m) 3.6 to 4 ppm.

EXAMPLE 2 (R)-2-Phenyl-2-methoxethanol 72 g of (R)-2-phenyl-2-methoxyacetic acid (prepared according to the method described in J. Chem. Soc., 1962, p.1519), are reduced with 16.5 g of lithium aluminum hydride in 300 ml of tetrahydrofuran.

The mixture is hydrolysed and the inorganic salts

II

are filtered off, and the residual oil is then distilled in a Kugelrohr. B.p. 15 imHa= 105 0 c.

I Yield: 76% Proton nuclear magnetic resonance spectrum (Solvent CDC11): 7.35 ppm; 1H(d) 4.35 ppm; 2H(mn) 3.65 ppm; 3H(s) 3.3 ppm; 1H (d exchangeable) 2.35 ppm.

Optical rotation in 1%_strength solution in ethanol: ii: EXAMPLE 3 2-phenyl- 2 portion t of Exampl (nm) ]24C 589 1220 578 1270 546 1450 436 2490 365 3960 ,8-Dioxa-3-oxo-10-phthalimidodecanoic acid 2-methoxyethyl ester 0 g of carbonyldiimidazole are added in a single o a suspension containing 34.7 g of the compound e 1 in 210 ml of methylene chloride.

10 The mixture is stirred until gaseous evolution has ceased. A mixture consisting of 17.7 g of Meldrum's acid and 9.2 g of pyridine in 70 ml of methylene chloride is then introduced in a rapid dropwise flow. The mixture is stirred overnight under nitrogen.

The mixture is transferred to a separating funnel, washed with N sulfuric acid to acid pH and then once with water and dried, and the solvent is evaporated off.

0 0 0I0 15 000ooo 00 0 a 0 20 00 0 0 0 o0oo 000: 20 25 000 2 0 00 00 0 0 The oil is taken to a water bath with 25 g of the alcohol obtained-in Example 2 until evolution has ceased.

The reaction medium is subjected to chromatography (flash chromatography) on a column containing 1.8 kg of silica, using a mixture of cyclohexane and ethyl acetate (1:1 V/V) as eluant, to obtain the expected compound.

Yield: Proton nuclear magnetic resonance spectrum (Solvent CDC1) 4H(m) 7.6 to 8.1 ppm; 5H(s) 7.35 ppm; 3H(m) 4 to 4.6 ppm; 2H(s) 4.1 ppm; 10H(m) 3.5 to 4 ppm; 3H(s) 3.3 ppm.

Optical rotation in 1% strength solution in ethanol: (nm) ]21C 589 35.10 578 36.50 546 41.4° 436 69.80 365 107.2 000 00 0 MO 0 EXAMPLE 4 3-Dichlorobenzvlidene)-3-oxobutanoic acid methyl ester A mixture containing 8.7 g of 2,3-dichlorobenzaldehyde, 5.8g of methyl acetoacetate, 28 drops of pyridine and 38 drops of hexanoic acid in 280 ml of benzene is brought to reflux with stirring for 4 hours. It is I I I- 11 transferred to a separating funnel and washed with strength sodium bicarbonate solution, then with N hydrochloric acid solution and then with water. The mixture is dried and evaporated. The crystals obtained are washed with isopropyl ether.

Yield: Proton nuclear magnetic resonance spectrum_(Solvent CDCl 1H(2s) 8 and 8.05 ppm; 3H(m) 7.1 to 7.8 ppm; 3H(2s) 3.9 and 3.75 ppm; 3H(2s) 2.45 and 2.2 ppm.

EXAMPLE (4R,4'R/4S,4'R)-4-(2,3-Dichlorohenvl 15 carbonyl-3-(2-methoxy-2-phenylethoxvcarbonvl meh 0s00 0 o 0a 00 00 0 1 an o o 2 G' 0 0 0 6 040 011 Oa 0 0 eo o 25 0 0 o a 0 00 2-f 2-(2-phthalimidoethoxvethoxvlmethylV-1,4-dihvdropyridine A mixture containing 22.2 g of the compound described in Example 4, 38 g of the compound described in Example 3 and 6.3 g of ammonium formate in 200 ml of ethanol is stirred under nitrogen at 40'C for 48 hours.

The residual medium is evaporated and purified on a column containding 4 kg of silica, using a mixture cousisting of methylene chloride and ethyl acetate (9:1 V/V) as eluant.

Protonnuclear_magnetic resonance spectrmn (Solvent CDC1) 0440 00 4 *I I 4. II 2H(m) 7.8 ppm; 2H(m) 7.7 ppm; 7H(m) 7.3 to 7.1 ppm; 1H(t) 7.05 ppm; 1H(s) 5.45 ppm; 2H(m) 4.6 ppm; 11H(m) 3.6 to 4.4 ppm; 3H(2s) 3.6 ppm; 3H(2s) 3.2 and 3.05 ppm; 3H(s) 2.3 ppm; 1H(s) not exchangeable with D 2 0, 7.4 ppm.

Opical rotationin 1%_strength solution in chloroform: A(nm) [a]21C 589 13.3° 578 13.80 546 15.1° such as, for example, vasorelaxation for the treatment of arterial hypertension and pulmonary hypertension and peripheral and coronary vascular diseases.

/2

A

12 EXAMPLE 6 (4R,4'R/4S,4'R)-2-rf2-r2-(2-Carboxyphenvlcarboxainido ethoxylethoxyl.methyl 1-4- methoxycarbonyl 3- 2 -methoxv- 2-phenyvlethoxvcarbonyl) -6 methyl-i, 4-dihydro]Ryridine A mixture containing 16.5 g of the compound of Example 5, 100 ml of 10% strength aqueous sodium bicarbonate solution and 230 ml of acetonitrile is brought to ref lux with stirring for 24 hours. The solvent is evaporated off and the residue is taken up with water, acidified with N hydrochloric acid aad extracted to obtain the expected compound.

Yield: 87%.

15 Proton nuclear magnietic resonance spectrum_(Solvent gDClj): lH(m) 7.9 ppm; 3H(m) 7.5 ppm; 7H(m) 7.4 to 7.15 ppm; lH(t) 7.05 ppm; lH(2s) 5.45 ppm; 2H(m) 4.8 ppm; 2H(m) 4.4 20 to 4.1 ppm; 111(m) 3.9 ppm; 8H(m) 3.8 to 3.5 ppm; 3H(2s) 3.6 ppm; 3H(2s) 3.2 and 3.05 ppm; 3H(s) 2.3 ppm; 111(t) 6.55 ppm; l1i (masked signal, exchanged with D 2 0) 7 .45 ppm; 1H (flat signal) 7 to 5 ppm exchanged with D 2 0.

O5 ptical rotation-in 1%_strength solution-in chloroform: -44 o .0 0.004 0.0 0 00# 0 0 44 .0 .0.0 0*40 .0 4* 00

II

6 4 0 0'0 0 40 04 0 0 ~0 04~ 4 0 .0 0 4~ 0 A (nm) [21'C 589 -14.2 0 578 1l4.8 0 546 -16.3 0 C 4.

0 00 0 00 EXAMPLE 7 Mixture of (-'-2-rU2-f2-(2-carboxvphenvlcarboxamido'ethoxyethoxmethyl1-4-(2,3-dichlorophenl1-3ethoxvcarbonvl-5-methoxvcarbonyl-6-methvl-i. 4-dihvdropyridine and its homolog substituted at the with an ethoxvcarbonvl radical First process The compound of Example 6 is separated into its two isomers by HPLC, using a Lichroprep RP18 50 cm long 12

V

13 13 as column and a mixture of methanol and 0.025M disodium phosphate (55:45 V/V) as eluant, flow rate 10 ml/min.

3 g of the second compound derived from the separation are brought to reflux with 30 ml of glyme and 28.6 ml of a 0.26M solution of sodium ethylate. The mixture is evaporated and the residue is taken up with water, acidified and extracted with ethyl acetate to obtain the expected compounds.

Overall yield: Second process STAGE A The compound of Example 5 is chromatographed on a preparative column containing 4 kg of silica, using a mixture of methylene chloride and ethyl acetate (95:5) as eluant. The first compound derived from the separation, which is the less polar, is isolated.

S° Yield: Proton nuclear magnetic resonance spectrum_(Solvent °0 o 20 CDCI) 2H(m) 7.8 ppm; 2H(m) 7.7 ppm; 7H(m) 7.4 to 7.1 ppm; 1H(t) 7.05 ppm; 1H(s) 5.45 ppm; 2H(m) 4.4 ppm; 11H(m) 4 to 3.7 ppm;3H(s) 3.6 ppm; 3H(s) 3.05 ppm;3H(s) 2.3 ppm; 1H(s) 7.45 ppm (exchangeable with D 2 O with difficulty).

SOptical rotation in 1% strength solution in chloroform: r r Ir t€ tt I t

III(

tS STAGE B X(nm) []21'C 589 9° 578 9.6° 546 10.40 3 g of the compound obtained in the preceding stage are brought to reflux with 30 ml of glyme and 28.6 ml of a 0.26M ethanolic solution of sodium ethanolate. The mixture is evaporated and the residue is taken up with water, acidified and extracted with ethyl acetate to obtain the expected compounds.

!ui~ 14 Yield: EXAMPLE 8 Mixture of (-)-4-(2,3-dichlorophenyl)-3-ethoxvycarbonyl-5-.methoxyvcarbonyl-6-methvl-2- rF2-(2-p~hthalimidoethoxy Iethoxy I met hyl 4-dihvdropyri dine and its homolox substituted at the 5-position with an ethoxvcarbonyl radical 1. 9 g of the mixture obtained in Example 7 are dissolved in 30 ml of methylene chloride and 0.9 g of carbonyldii-midazole is added in a single portion. The mixture is left stirred overnight.

The reaction medium is transferred to a separating funnel and washed with 10% strength sodium bicarbonate and then with N hydrochloric acid and with water.

The mixture is dried and evaporated to obtain the expected compounds.

Yield: EXAMPLE 9 (2,.3-Dichlorophenyl methoxycarbonyl-6-methyl-2-i F2-(2-phthalimidoethoxy,ethoxylmethyll-1 ,4-dihvdrop)Yridine The mixture obtained in Example 8 is separated -by preparative HPLC, using a Lichroprep RP 18 column 50 cm long and a mixture of ethanol, water and TFA (500:500:1) as eluant. The expected compound is isolated first.

Yield: Optical rotation-in 1%_st'rength solution-in DMSO:

II

a a.

C

GO C a 09 p pp

I

15 EXAMPLE (-)-2-{r2-(2-AminoehoxYethoxym)ethlmethyl-4-(23- 6 methyl-l,4-dihydropyridine 1 g of the compound prepared in Example 9 is refluxed with 10 ml of ethanol and 0.25 ml of hydrazine hydrate for 4 hours. The solvent is evaporated off, the residue is taken up with ethyl ether and washed with 5 ml of normal sodium hydroxide and the ether phase is exhaustively extracted with N hydrochloric acid. The aqueous phases are then alkalinized and extracted with ethyl ether to obtain the expected compound.

Yield: Melting point: 69 0 -71 0

C.

15 Proton nuclear magnetic resonance spectrum_(Solvent o* 0 CDC1,) 1 H(m) 7.3 to 7.7 ppm exchangeable with DzO; 3H(m) 7.6 to a 20 6.9 ppm; 1H(s) 5.5 ppm; 2H(s) 4.8 ppm; 2H(q) 4 ppm; 4H(s) 3.7 ppm; 2H(m) 3.4 to 3.7 ppm; 3H(s) 3.6 ppm; 2H(t) 2.9 ppm; 3H(s) 2.3 ppm; 2H(m) exchangeable with D 2 0 1.4 to 1.8 ppm; 3H(t) 1.2 ppm.

Optical rotation in 1% strength solution in chloroform: 0440 Sr S 0I Sd A(nmn) I ]20.5C 589 36.50 578 38.7 546 46.80 436 -113° EXAMPLE 11 r2-(2-Aminoethoxvyethoxy]methyl}-4-(2,3dichloroDhenvl)-3-ethoxvcarbonyl-5-methoxycarbonyl-6methyl-1,4-dihydropyridine fumarate (-)-2-{[2-(2-Aminoethoxy)ethoxy]methyl}-4-(2,3dichlorophenyl)-3-ethoxycarbonyl-5-methoxycarbonyl-6methyl-1,4-dihydropyridine fumarate is obtained after solubilization of 4.2 g of base in 50 ml of a 0.172M 16ethanolic solution of fumaric acid. It is recrystallized in acetonitrile.

Yield: 92% Melting point: 115 -C Proton nuclear magnetic resonance spectrum_(Solvent gDCl,. and qDMSO-d~: 2H(2dd) 7.3 ppm; 1ii(t) 7.1 ppm; 2B3(s) 6.7 ppm; 1H(s) 5.45 ppm; 2H(m) 4.7 ppm; 2H(q) 4 ppm; 6H~ml1 5.7 ppm; 3H(s) 3.6 ppm; 2H(m) 3.1 ppm; 3H~s) 2.3 ppm; 3H(t) 1.3 ppm; 1H(s exchanged D 20) 7.7 ppm; 4H(s exchanged D 1)0) 5.7 ppm.

Optical rotation-in l%-strength solution-in DMSO: X(rn) 589 33 .1 0 578 35 .2 0 9 20 546 43.0 0 436 -134.6 0 EX.AMP~LE 12 dichlorophenyl 3-ethoxycarbonvl-5-methoxvcarbonyl- 6 methyl-i. 4-dihydropyridine -tartrate, 0.2 g of the compound of Example 10 is dissolved in 3.1 ml of a 0.133M4 ethanolic solution of (+)-tartaric acid. After evaporation of the solvent, 0.24 g of the expected salt is obtained.

Meting poti:-in~ 1% stre nqth solution-in DMSO: x (nm) [21. VC 589 -29.9 0 578 -32.50 546 -40.50 436 -133.90 17 EXAMPLE 13 dichiorophenyl -3-ethoxycarbonyl-5--methoxycarbonyl-6methyl-i .4-dihydropyridine (-)-tartrate 0.3 g of the compound of Example 10 is dissolved in 4.6 ml of a 0.133M ethanolic solution of (-)-tartaric acid. The expected salt is isolated after filtration.

Melting point: 161-166 0 C (sublimation) O0 ptical rotation-in 1%_strength solution-in DMSO: 589 32 .90 578 -35 0 1 546 42.8 436 142 o0 0 00 a.

0 00 0 0 0 0 0 20 00000 *0000 0 10 C,0 025 000 00 0 0 00 0~ EXAMPLE 14 (-)-2-f2-(2-Aminoethoxy)ethoxylmethyl dichlorophenyl)-3-ethoxycarbonvl-5-methoxycarbonyl-6methyl-i, 4-dihvdropyridine racemic tartrate 0.45 g of the compound of Example 10 is dissolved in 6.9 ml of a 0.133M ethanolic solution of racemic tartaric acid.

The expected salt is isolated after filtration.

Melting point: 160-170*C Optical rotation-in 1%_strength solution_,in DMSO: 0000 O 0 00 0 0 0 0 00 []21.5*C 589 31.20 578 33-50 546 41.10 436 -135.90 pot..

0069 aa 6 00 00 a o,

C'

.a 0 0 0ile 18 PHARMACOLOGICAL STUDY EXAMPLE Affinity for the dihydropyridine binding site Study of the displacement by ethoxy)ethoxy]methyl}-4-(2,3-dichlorophenyl)-3-ethoxycarbonyl-5-methoxycarbonyl-6-methyl-l,4-dihydropyridine and by its racemate of tritiated PN 200-110 bound specifically to the dihydropyridine site associated with the calcium slow channel enabled it to be demonstrated that the compound of the invention exhibits an affinity for these sites which is 30 times as great as its racemate.

This study was carried out on microsomal membrane preparations prepared from skeletal muscle of rat (Wistar) hind limbs.

15 The rats are killed by decapitation. The skeletal muscles are removed and washed in buffer I (20 mM MOPS/ KOH pH 7.4, 0.3 M sucrose, 1 mM EDTA, 0.1 mM iodoacetamide, 1 iM pepstatin A, 1 mg/l leupeptin and 0.1 pM PMSF). The muscles are then mechanically fragmented, taken up in 4 volumes of buffer I per gramme of tissue and homogenized.

The homogenate is then centrifuged for 10 minutes at 3,200 g, the pellets are removed and the supernatants are then centrifuged for 20 minutes at 15,000 g, and the supernatants are stirred for 15 minutes at 4°C in buffer I containing 0.6M final KC1 and then centrifgued for minutes at 70,000 g.

The pellets are taken up in buffer I and homogenized in a Potter. The homogenates are centrifuged at 30 100,00.0 g for 45 minutes and the pellets thereby obtained correspond to the microsomal fraction used for the studies of binding and displacement.

The activity of the product is assessed by the displacement of 200-110, bound specifically to its receptor associated with the calcium slow channel, by increasing concentrations of the test products. The value obtained (K0.5) for each of the products, which represents the concentration of the product displacing 50% of the 3 H]-PN 200-110, permits calculation of a true dis- 0000 0 0i 0 00 0I 0 0 0404 00 ir i_ 1 I i: I- i i 19 sociation constant IK Kd where is the concentration of free 3 H]-PN 200-110 and Kd the dissociation constant at equilibrium of the 3 H]-PN 200-110 complex, determined by direct binding.

The KI values of the two products are recorded in Table I: TABLE I .444 4 4 44Gw

I

4r 44 1 1'4 4 4 4 4 44 COMPOUND KI EXPRESSED IN nM COMPOUND OF THE INVENTION 0.28 0.15 RACEMATE 8.2 1.7 15 EXAMPLE 16 Study on isolated rabbit mesenteric artery contracted with calcium This test is performed on organs removed from male New Zealand rabbits weighing 2.5 to 3 kg, subjected to a water regimen for 18 hours before sacrifice.

After the animal is rapidly sacrificed, the mesenteric artery is removed and dissected into rings 2 mm long; the endothelium is removed mechanically.

After a stabilization period of 90 minutes, the preparations are subjected to a depolarizing medium (35 mM KC1) without calcium (0.1 mM EGTA) for 15 minutes.

A control series is prepared by adding cumulative doses of calcium to the bath every 6 minutes until a maximum of effect is produced. The preparations are then rinsed for a period of 15 minutes and the product is incubated for one hour before renewal of the calcium series.

A single concentration of the product is tested per organ.

The responses obtained in the presence of product are expressed as a percentage of the maximal value of the control series.

0

Q

peripheral and coronary vascular diseases (Am. J. Card.

1980, 46, p.1047-1058; Burger's Medicinal Chemistry 4th edition, part III, p.5456 John Wiley and Sons Inc. USA, 1981; Life Sciences, 1983, 33, p.

2 571-2581). Induced im mi.n 1,I II 20 The pD'2 value is calculated according to the method of Van Rossum (1963).

The pD'2 values of the compound of the invention and its racemate appear in Table II. These data show the very marked superiority (more than double) of the compound of the invention, compared with its racemate, in preventing a calcium-induced vascular contraction.

TABLE II o I 0 0 0 0000 *O I

I,

@44.

15 COMPOUND pD'2 COMPOUND OF THE INVENTION 7.97 RACEMATE 7.64 EXAMPLE 17 Study in unanesthetized spontaneously hvpertensive rats (SHR) SHR male rats weighing 280 to 350 g and aged from 18 to 24 weeks are anaesthetized with imalgene" (150 mg/kg Two polyethylene catheters are introduced, one into the abdominal aorta for the recording of hemodynamic parameters and the other into the jugular vein for the administration of the products. The catheters are taken through to neck level. The animals are used at least 48 hours after surgical intervention.

The systolic and diastolic abdominal bood pressures are recorded by means of a Statham P23XL transducer on a Gould ES 1000 recorder. The products are administered intravenously in a volume of 0.5 ml/kg. The doses 30 administered of the test compounds are expressed in mg/kg of base. The blood pressure is recorded in continuous fashion up to 6 hours after the treatment.

The changes in systolic blood pressure after treatment are recorded in Table III.

The compound of the invention is distinguished from its racemate by its activity, which is more potent and sustained even better over a period of time, this constituting a considerable advantage in therapy. In effect, for the same dose six hours after treatment, the tort 0 t 00 00 0 00 0 00 A i -21 activity of the compound of the invention is approximately 4 times as great as that of its racemate.

TABLE III f 4 44

A

it' '1

V

Systolic blood pres- DOSE changes (AnHg) COMPOUND (mg/kg) after treatment 1H 30 min 3H 6H COMPOUND OF THE INVENTION 0.1 -16±2 -18±2 -21± RACEMATE 0.1 -11±3 -5±3 PHARMACEUTICAL PREPARATION EXAMPLE 18 Tablets containing a 1 mg dose of ethoxy)ethoxy]methyl}-4-(2,3-dichlorophenyl)-3-ethoxycazrbonyl-5-methoxycarbonyl-6-methyl-1 ,4-dihydropyridine A.D.E.M.M.D.P 1mg Starch 64 mg Cellulose 25 ma Alginic 10 mg 25 per tablet of theoretical weight 100.00 mg.

Claims (3)

1. (-)-2-{[2-(2-Aminoethoxy)ethoxyjmethyl}-4-(2,3- dichiorophenyl) -3-ethoxycarbonyl-5-methoxycarbonyl-6 methyl.-1,4-dihydropyridine, the compound of fo.xmula I: YCI 3 C-0-C -C-0-CH 2 CH 3 (I H3C H CH2-0-CH2CH 2 -0-CH 2 CH 2 NH- 2 0 0 0and its addition salts with a pharmaceutically acceptable Q0 inorganic or organic acid.

02. A process for preparing the compound -ef fermula 0I, C4~v wherein 2-[2-(2-chloroethoxy)ethoxy]ethanol is condensed with potassium phthalimide, in dimethylformamide in-the- 1hceatcd -state, to form 2-[2-(2-phthalimidoethoxy)ethoxy]- ethanol, the compound of formula II o 0 QN-CH2CH20CH2 CH 2 OCH 2 CH 2 OH (II) 0 cce.ioe cc(-q ile,erw(Ure beAAee 2-0,'o 2C which is converted by means of Jone~ reagent~to phthalimidoethoxy)ethoxy] acetic acid, the compound of formula III: 0 Q N-C H 2 C H 2 0CH 2 C H 2 0C H 2 CO 0H which is treated with carbonyldiimida~ole and Meld.;umx's otf-roovi e'Me41~rre- acid in the presence of pyridine in methylene chforige.'to obtain the compound of formula IV: A mixture containing 8.7 g of 2, 3-dichlorotenza.L- dehyde, 5.Bg of methyl acetoacetate, 28 drops of pyridine and 38 drops of hexanoic acid in 280 ml of benzene is brought to ref lux with stirring for 4 hours. It is I 23 CH 3 0 0 C -C H 2 CH 2 CH 2 oCH 2 CH2- CH 3 0 (IV) which is then reacted~with (R)-2-phenyl-2-methoxyethanol, the compound of formula V: (R) CH-CH 2 0H (V OCH 3 0040 4' 44 0 0 4404w o o 1 04 04 04 04 0 0 4 4 44 to obtain the p-keto ester of formula VI: 0 0 1 1 1 (VI) 2 CH 2 OCH 2 CH 2 0C which is condensed in the presence of ammonium formate in c4- 4-o 0 c ethanol~with a benzylidene compound of formula VII: (VII) H 3 C to obtain (4R,4'R/4S,4'R)-4-(2,3-dichlorophenyl)-5- methoxycarbonyl-3- (2-methoxy-2-phenylethoxycarbonyl) -6- methyl-2- (2-plithalimidoethoxy) ethoxy ]methyl 4- dihydropyridine, the compound of formula VIII: 6

24- C1 C CHO 1R. (VIII) 3CH N CH 2 OCH 2 CH 2 0CH 2 CH2N H (4R,4'R/4S,4'R o and then: either: this compound is subjected to the action of aq1eou~ sodium bicarbonate solution, in solution in acetonitrileA to obtain (4R,4'R/4S,4'R)-2-[{2-[j2-(2-carboxyphenyl- carboxamido )ethoxy]ethoxylmethyl] 3-dichiorophenyl) 5-methcoxycarbonyl-3-(2-methoxy-2-phenylethoxycarbonyl) 6-methyl-l,4-dihydropyridine, the compound of formula IX: C1 CH 3 00C C R 10C-0 COO (IX) P OCH 3 CH 3 N CH2OCH 2 CH 2 OCH 2 CH 2 NH-C H 0 0 C, 04Pe (4R, 4' R/4S,4 'R) ,'er7or ry i1/. s -k4rq, which F;trce d in~ thc hctdqtt ith a mixture of glyme and sodium ethylate to obta~in a mixture containing (-)-2-[{2-[2-(2-carboxyphenylcarboxamido)ethoxy]ethoxyY- methyl 1-4- 3-dichiorophenyl) oxycarbonyl-6-methyl-1 4-dihydropyridine, the compound of formula X: (~AL 0 4 h CI 0 CI CH300C COOC 2 H 5 COOH (X) CH 3 N N'CH 2 0CH 2 CH 2 0CH 2 CH 2 NH H O and its homolog substituted at the 5-position with an ethoxycarbonyl radical, or: the compound of formula VIII is separated by chromato- graphy on a silica column, using a mixture of methylene chloride and ethyl acetate (95:5 V/V) as eluant, to obtain the less polar isomer of 4-(2,3-dichlorophenyl)- 5-methoxycarbonyl-3-(2-methoxy-2-phenylethoxycarbonyl)- 6-methyl-2-{[2-(2-phthalimidoethoxy)ethoxy]methyl}-1,4- dihydropyridine, which is then subjected to the action of sodium ethanolate/ir( the presence of glyme in solution in ethanol to obtain a mixture containing the compound of formula X and its homolog substituted at the with an ethoxycarbonyl radical, which is then subjected to the action of carbonyldiimidazole in solution in a halogenated alkane at room temperature to obtain a mixture containing (-)-4-(2,3-dichlorophenyl)-3-ethoxy- carbonyl-5-methoxycarbonyl-6-methyl-2-{[2-(2-phthalimido- o 20 ethoxy)ethoxy]methyl}-1,4-dihydropyridine, the compound 0 0. of formula XI: CI O C1 CH300C COOC2H O CH3 N CH20CH2CH20CtH2CH2N H and its homolog substituted at the 5-position with an j 25a ethoxycarbonyl radical, which mixture is then separated by (reverse phase) HPLC to obtain pure (-)-4-(2,3-dichlorophenyl)-3-ethoxycarbonyl-5-methoxycarbonyl-6- methyl-2-{[2-(2-phthalimodoethoxy)ethoxy]methyl}-1,4-dihydropyridine, which is then brought to reflux in ethanol in the presence of hydrazine hydrate to give the compound of formula I, which can then be salified with a pharmaceutically compatible organic or inorganic acid. 3. A pharmaceutical composition containing, as active principle, the compound as claimed in claim 1, in combination or mixed with a pharmaceutically acceptable, non- toxic, inert vehicle or excipient. 4. The pharmaceutical composition as claimed in claim 3, containing the active principle at a dose of 0.02 to 50 mg. A method of treating a living animal or human body afflicted with diseases requiring calcium modulators which comprises administering to said living body an effective amount of the compound of claim 1. S6. A method of treating a living animal or human body afflicted with atheroma which comprises administering to said living body an effective amount of the compound of claim 1. a a ;II 26 dihydropyridine, which is then brought to flux in ethanol in the presence of hydrazine hydrat to give the compound of formula I, which can then be alified with a pharmaceutically compatible organic o inorganic acid. 3. A pharmaceutical compos ion containing, as to active principle, the compound s claimed in claim 1, in combination or mixed with a armaceutically acceptable, non-toxic, inert vehicle r excipient. The pharmace ical composition as claimed in claim 3, containi the active principle at a dose of *4 OO 15 0.02 to 50 mg. 4 2 The harmaceutical composition as claimed in claims 3 and 4, which is usable in the treatment of 0diseas s requiring calcium modulators. 6. The pharmaceutical composition as claimed in aims 3 and 4, which is usable in the tretment of athtoma o 7. (4R,4'R/4S,4'R)-4-(2,3-Dichlorophenyl)-5-methoxy- carbonyl-3-(2-methoxy-2-phenylethoxycarbonyl)-6-methyl- 2-{[2-(2-phthalimidoethoxy)ethoxymethyl}-,4-dihydro- pyridine, the compound of formula VIII: CI 1" a CH< N (VIII) H (4R4'R/4Sj'R) O ethanl i I "Y_ c g copon o frul hihca te b liie it 27 an intermediate which is useful for the preparation of the compound of formula I as claimed in claim 1. DATED THIS 29th day of September, 1989 ADIR Er COMPAGNIE WATERMARK PATENT TRADEM1ARK ATTORNEYS, 50 QUEEN STREET, MELBOURNE. VICTORIA, 3000. C ~9 C C 4 CC q C 9 44 4 4