JPH07118247A - Thiazoleacetic acid derivative - Google Patents

Abstract

PURPOSE:To obtain a novel thiazoleacetic acid derivative consisting of a N- benzyl-thiobenzamide-thiazoleacetic acid derivative, having phosphodiesterase- inhibiting activity, exhibiting smooth muscle relaxing action and anti- inflammatory action, etc., and useful as an anti-inflammatory agent, a bronchodilator, etc. CONSTITUTION:A new thiazolacetic acid derivative expressed by formula I (X<1> to X<4> are halogens) has phosphodiesterase-inhibiting activity, and exhibits blood vessel smooth muscle-relaxing action, air duct smooth muscle-relaxing action, platelet aggregation-suppressing action, anti-inflammatory action, etc. This is useful as an anti-inflammatory agent and a bronchodilator {e.g. 2-[N-(3,4- dichlorobenzyl)-3,4-dichlorothiobenzamide]-4-thiazolacetic acid}. This compound is obtained by successively reacting an 2-aminothiazol-4-yl-acetic acid ester of formula II (Et is ethy) with a dihalogenobenzyl compound of formula III (R<2> is Cl, Br, etc.) and a dihalogenobenzoyl compound of formula IV (R<1> is Cl, Br or OH) and then, hydrolyzing the resultant ester.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a thiazoleacetic acid derivative having phosphodiesterase inhibitory activity.

[0002]

2. Description of the Related Art Conventionally, it has been known that a drug which increases intracellular cAMP concentration regulates cell function,
One of the drugs that increase cAMP is an inhibitor against phosphodiesterase (PDE) which is a cAMP degrading enzyme. At least five isozymes are known for PDE, and various effects can be expected by inhibiting each isozyme. Each isozyme is classified as follows using the substances that affect the distribution and in vitro PDE activity as indicators. PDEI is distributed in cardiac muscle, brain, liver and the like, and is characterized by its enhanced activity in the presence of Ca ²⁺ and calmodulin.
Is characterized by an enhanced activity in the presence of cGMP. PDE III is distributed in myocardium, blood vessels, platelets, etc.
It is characterized in that the activity is inhibited in the presence of cGMP.
PDE IV is distributed in the brain, trachea, kidney, and white blood cells (neutrophils, mast cells, macrophages, eosinophils, etc.), and cAMP
It is characterized by reacting specifically with. PDE V is characterized in that it is distributed in vascular smooth muscle, platelets, etc. and reacts specifically with cGMP. The effects of PDE inhibitors are expected to be vascular smooth muscle relaxing action, airway smooth muscle relaxing action, platelet aggregation inhibiting action, anti-inflammatory action and the like. As described above, PDEs having an inhibitory effect on all isozymes have various inhibitory effects depending on each isozyme.
Xanthine derivatives are known as inhibitors. One of them, theophylline, is widely used as an anti-inflammatory agent, bronchodilator, and platelet aggregation inhibitor, but its effect is weak and side effects have been reported. In addition, as the most effective PDE inhibitor among xanthine derivatives, IBM
X (3-isobutyl-1-methyl-xanthine) is known (Ch
ristian S., Biochemical Pharmacology. vol. 42, No.
1, p153-162, 1991; referred to below).

[0003]

Therefore, the present inventors have
As a result of earnest research on a compound having a stronger PDE inhibitory activity, a thiazole acetic acid derivative having a chemical structure completely different from that of the xanthine derivative was found. That is, an object of the present invention is to provide a novel drug having a PDE inhibitory activity, particularly a thiazole acetic acid derivative useful for anti-inflammatory action and bronchodilator action.

[0004]

The present invention has the following general formula (I):

[Chemical 2] ( ^Wherein X ^1-4 represents the same or different halogen atoms) and a thiazoleacetic acid derivative or a salt thereof. The compound (I) of the present invention will be described in detail below. X ^1-4
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a chlorine atom is preferable. In the compound (I) of the present invention, tautomers, various hydrates, various solvates, crystal polymorphisms, etc. may exist in some cases, but the compounds of the present invention include isolated compounds of these compounds and All compounds of the mixture are included. Further, the compound of the present invention can form a salt, and the present invention also includes pharmaceutically acceptable salts of compound (I) and its isomer. Such salts include lithium, sodium,
Salts with alkali metals such as potassium, salts with alkaline earth metals such as magnesium and calcium, aluminum salts,
Examples thereof include ammonium salts and salts with organic bases such as trimethylamine and triethylamine. These salts can be derived by a conventional method.

The method for producing the compound of the present invention will be described in detail below.

[Chemical 3]

(Wherein X ^1-4 is as described above, R ¹ is a chlorine atom or a bromine atom, or a hydroxyl group, R ² is a chlorine atom, a bromine atom or an iodine atom, a methanesulfonyloxy group, or paratoluene. A sulfonyloxy group and the like are meant.) In order to produce the compound (I) of the present invention, first, ethyl 2-
Aminothiazol-4-ylacetate (II) is used as a raw material, and this is reacted with a dihalogenobenzoyl compound (III) and a dihalogenobenzyl compound (V) to synthesize a thiazoleamide compound (VI) and thioamidation thereof. .

A method for synthesizing a thiazole amide compound (VI), which is an intermediate in the process of producing the compound (I) of the present invention, can be carried out by using ethyl 2-aminothiazol-4-yl acetate (II) and a dihalogenobenzoyl compound (II). III) and by reacting in the presence of a base under ice cooling or heating
(IV) and then the obtained (IV) is reacted with the dihalogenobenzyl compound (V) in the presence of a base at room temperature or under heating to obtain (VI) (method a), or Raw material ethyl 2-aminothiazole-
(VII) was obtained by reacting 4-ylacetate (II) with dihalogenobenzyl compound (V) in the presence of a base at room temperature to heating, and then obtaining (VII) with dihalogenobenzoyl compound (V). There are two methods, ie, a method of obtaining (VI) by reacting with III) in the presence of a base under ice cooling or under heating (process b).

The thiazole amide compound (VI) obtained by these methods is heated to reflux in a solvent such as toluene, benzene, or pyridine using Lawesson's reagent or phosphorus pentasulfide to convert the amide moiety into a thioamide. The compound (I) of the present invention can be obtained by converting it to (VIII) and subjecting this to hydrolysis in a conventional manner. a
Dihalogenobenzoyl compound in the production method and the production method b
When the substituent represented by R ¹ in the formula (III) is a chlorine atom or a bromine atom, triethylamine or pyridine is used as a base, chloroform, dichloromethane,
The reaction can be carried out using benzene, toluene, tetrahydrofuran or the like as a solvent. On the other hand, when R ¹ is a hydroxyl group, the reaction can be carried out using a conventional DCC method, an active ester method, or a mixed acid anhydride method.

The dihalogenobenzyl compound (V) is a base such as sodium hydride, potassium hydride, sodium ethoxide, sodium amide, n-butyllithium, potassium hexamethyldisilazide, sodium hydroxide, potassium hydroxide or carbonic acid. The nucleophilic substitution reaction can be carried out in an organic solvent inert to this reaction such as tetrahydrofuran, dimethylformamide, dimethylsulfoxide, ethanol, acetonitrile, methylethylketone or toluene using potassium or the like.

[0010]

INDUSTRIAL APPLICABILITY The compound (I) of the present invention exhibits vascular smooth muscle relaxing action, airway smooth muscle relaxing action, platelet aggregation inhibiting action, anti-inflammatory action and the like by inhibiting PDE activity. It is useful as a dilator. Experimental method PDE activity measurement method This method was carried out according to the method of the above cited document. 5 mM
Tritium-labeled cAMP or cGMP (1 μM) is added to 40 mM Tris-hydrochloric acid buffer solution (pH 8.0) containing magnesium chloride and 4 mM 2-mercaptoethanol to prepare buffer solution A and buffer solution G, respectively. Rat ventricle or human monocyte U9 was added to 200 μl of buffer A or buffer G.
20 μl of each isozyme of PDE separated from 37 was added, and 2.2 μl of the test compound was added thereto, and 1
Let react for 0 minutes. The reaction is stopped by immersing it in warm water of 90 ° C. for 45 seconds, and leaving it in ice for 1 minute. Then, 50 μl of 5′-nucleotidase is added and reacted at 30 ° C. for 10 minutes.
Add 1 ml of methanol to this to stop the reaction, and
Pass through a Dowex 1-x8 column. Further, this column was washed twice with 0.5 ml of methanol, and 6 ml of a liquid scintillator was added to the combined filtrate, and the radioactivity was measured. The PDE activity was measured by the radioenzyme assay method as described above. Each isozyme of PDE, I, II, III, IV type from rat ventricle,
Type IV from human monocyte U937, Q-sepharose fas
It was isolated by the method using a t frow column and used. All the drugs were used after being dissolved in dimethyl sulfoxide.

Method for preparing PDE from tissues and cultured cells 1) Preparation from rat ventricle Ventricle was excised from 4 SD rats (male, 8 weeks old) and, after cutting into small pieces, 10 mM Tris-HCl buffer (2 mM magnesium chloride, 1 mM) Dithiothreitol, 0.23 TIU / ml
Add 10 ml of aprotinin) and homogenize using a polytron. 26000 this tissue fluid
Centrifuge at rpm for 15 minutes, collect the supernatant and 0.45 mM
Filter with the filter. 2) Preparation from Cultured Cells To 5 × 10 ⁸ U937 cells cultured in RPMI 1640 medium, 10 mM Tris-HCl buffer (2 m) was added.
M magnesium chloride, 1 mM dithiothreitol, 0.
23 TIU / ml with aprotinin added) 10 ml
Add the cells and disrupt the cells using an ultrasonic disruptor. This tissue fluid is centrifuged at 32000 rpm for 60 minutes, the supernatant is taken and filtered with a 0.45 mM filter. 3) Separation using Q-sepharose The Q-sepharose column was equilibrated with 10 mM Tris-HCl buffer (pH 7.4) containing 2 mM magnesium chloride, and the tissue and cell lysate obtained in 1) and 2). Pass through. After washing with 50 mM sodium acetate, a 50 mM to 1000 mM sodium acetate concentration gradient is applied for elution. After that, it is washed with 1000 mM of sodium acetate and fractionated at regular intervals. Q-sepharose f
From the tissue and cell lysate obtained in 1) and 2) by the sodium acetate gradient method using ast frow column, PDE
Isozymes are separated and used in the assay.

Activity of Target Compound The inhibitory activity of the compound (I) of the present invention determined by the above method is shown below.

[Table 1] From the above results, it was found that the compound (I) of the present invention is a very potent non-selective PDE inhibitor.

The pharmaceutical preparation of the present invention containing one or more kinds of the compound represented by the general formula (I) or a salt thereof as an active ingredient is a carrier, an excipient and other additives which are usually used for the preparation. Using tablets, pills, capsules, granules,
It may be in any form of oral administration such as powder, or parenteral administration such as injection, inhalation, suppository and transdermal administration. The dose is appropriately determined in consideration of the symptoms, weight, age, sex, etc. of the patient to whom it is applied.

EXAMPLES The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0014]

[Chemical 4] (I) To 60 ml of a chloroform solution of 5.58 g of ethyl 2-aminothiazol-4-yl acetate, 3.64 ml of triethylamine was added, and the mixture was stirred under ice cooling. To this solution was added dropwise 10 ml of a chloroform solution of 7.54 g of 3,4-dichlorobenzoyl chloride, the mixture was stirred at room temperature for 10 minutes, and then heated under reflux for 5 hours. After cooling, the reaction solution was washed with saturated aqueous sodium hydrogen carbonate solution, 10% hydrochloric acid and saturated saline, and then dried over anhydrous magnesium sulfate. The solvent was distilled off under reduced pressure, and the obtained crystals were washed with a mixed solvent of n-hexane and ether to give ethyl 2- (3,4-
7.77 g of dichlorobenzamido) thiazol-4-yl acetate was obtained.

(Ii) Sodium hydride 0.44 g (60
% Of mineral oil) in N, N-dimethylformamide suspension, 3.59 g of ethyl 2- (3,4-dichlorobenzamido) thiazol-4-yl acetate obtained above was added little by little. After all the additions were completed, the mixture was stirred at 50 ° C for 30 minutes and cooled again. 3,4-dichlorobenzyl chloride 2.15 g N, N-dimethylformamide solution 30 m
1 was added dropwise, and after the addition, the mixture was stirred at 80 ° C. for 2 hours. The solution was evaporated under reduced pressure, water was added to the residue, and the mixture was extracted with dichloromethane. The organic layer was dried over anhydrous magnesium sulfate, and the solvent was distilled off. The residue was subjected to silica gel column chromatography, and a mixed solvent of n-hexane-ethyl acetate (2:
1) The crystals obtained from the eluate were washed with a mixed solvent of n-hexane and ether and washed with ethyl 2- [N- (3,4
3.06 g of -dichlorobenzyl) -3,4-dichlorobenzamido] thiazol-4-yl acetate were obtained.

(Iii) 1.22 g of Lawesson's reagent and 20 ml of toluene were added to 2.07 g of ethyl 2- [N- (3,4-dichlorobenzyl) -3,4-dichlorobenzamido] thiazol-4-ylacetate. Heated to reflux for hours. The solvent was distilled off under reduced pressure, and the residue was subjected to silica gel column chromatography. The crystals obtained from the n-hexane-chloroform (1: 1) eluate were washed with ether to give ethyl 2- [N- (3,4-dichlorobenzyl) -3,4-dichlorothiobenzamido] thiazol-4-yl. 1.6 g of acetate was obtained.

(Iv) Ethyl 2- [N- (3,4-dichlorobenzyl) -3,4-dichlorothiobenzamide]
To 1.5 g of thiazol-4-yl acetate was added 10 ml of 1N sodium hydroxide and 30 ml of methanol,
The mixture was stirred at 70 ° C for 1 hour. Methanol was distilled off, water was added to the residue, and the mixture was neutralized with 1N hydrochloric acid. The precipitated crystals are washed with isopranol to give 2- [N- (3,4-dichlorobenzyl) -3,4-dichlorothiobenzamide] -4.
-1.15 g of thiazole acetic acid was obtained. Melting point 200 to 203 ° C. (decomposition) Nuclear magnetic resonance spectrum (DMSO-d ₆ , TMS internal standard)

Δ: 4.00 (2H, s), 5.72 (2
H, s), 7.08 (1H, dd, J = 8Hz, 2H
z), 7.28 (1H, s), 7.54 (1H, d, J
= 2 Hz), 7.58 (1H, d, J = 8 Hz), 7.
60 (1H, d, J = 8Hz), 8.12 (1H, d
d, J = 8 Hz, 2 Hz), 8.18 (1H, s)

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display area A61K 31/425 AED // C12N 9/99

Claims (1)

[Claims] 1. A compound represented by the general formula (I): ( ^Wherein X ^1-4 represents the same or different halogen atoms) and a thiazoleacetic acid derivative or a salt thereof