JPH047749B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention provides novel dimethyl-5,6-dihydroimidazo[2,1-b]thiazole-2-carboxanilide derivatives, more specifically, an excellent immunomodulating compound. The following general formula with the effect () (wherein, R is a phenyl group, [Formula] (R ₃ is a chlorine atom, bromine atom, iodine atom, lower alkyl group, lower alkoxy group, or nitro group) or [Formula] (R ₄ is a halogen atom, Lower alkoxy group or trifluoromethyl group,
R ₅ represents a halogen atom, hydroxyl group, lower alkoxy group or trifluoromethyl group), and R ₁
and R ₂ are the same or different and represent a hydrogen atom or a lower alkyl group. The _present invention relates to dimethyl-5,6-dihydroimidazo[2,1-b]thiazole-2-carboxyanilide derivatives and salts thereof, represented by: [Prior Art] Conventionally, many compounds having an imidazothiazole skeleton have been synthesized, for example, the following formula: It has been reported that the imidazo[2,1-b]thiazole derivative (levamisole) represented by
issue). Also, the expression (In the formula, R ₉ is a C ₁ to _{C 3} alkylsulfonyl or [Formula] group, R ₁₃ and R ₁₄ independently represent hydrogen, monofluorophenyl, trifluoromethylphenyl, or trimethylphenyl, but at the same time not hydrogen, or R ₁₃ and R ₁₄ together with the nitrogen atom to which they are attached form cis-dimethylpyrrolidine; R ₁₀ is C ₁ -C ₃ alkyl or phenyl; R ₁₁ and R ₁₂ are independently represents hydrogen or a _C1 - _C4 alkyl group) [U.S. Pat. No. 4,224,334, Journal of Medicinal Chemistry (J.Med.
Chem.) 24 , 604-609 (1981)] and formula (wherein R ₁₅ represents a substituted or unsubstituted phenyl group or naphthalyl group)
-b] Thiazole derivative (JP-A-57-169490)
has been reported to have anti-inflammatory effects. [Means for Solving the Problems] Under these circumstances, the present inventors synthesized various imidazo[2,1-b]thiazole derivatives and investigated their physiological activities. It has been discovered that novel dimethyl-5,6-dihydroimidazo[2,1-b]thiazole-2-carboxyanilide and its salts represented by the above formula () have excellent immunomodulatory effects, and the present invention has been completed. did. That is, the present invention provides dimethyl-5,6-dihydroimidazo[2,1-
b] Thiazole-2-carboxyanilide derivatives and salts thereof. In the present invention, preferred examples of the group represented by R in formula () include the following. [Formula] [Formula] [Formula] [Formula] [Formula] [Formula] [Formula] [Formula] [Formula] [Formula] [Formula] [Formula] [Formula] [Formula] [Formula] Also, the group -CH ₃ is 5 of imidazothiazole skeleton
or substituted at the 6-position, preferably a 3,6-dimethyl-5,6-dihydroimidazo[2,1-b]thiazole-2-carboxyanilide derivative substituted at the 6-position with a -CH ₃ group. Examples of the salts of the compound () of the present invention include pharmaceutically acceptable salts such as hydrochloride, sulfate, carbonate,
Inorganic or organic acid salts such as nitrates, hydrobromides, phosphates, sulfonates, acetates, oxalates, tartrates, citrates, malates, glutamates, aspartates, etc. Can be mentioned. Further, the compound of formula () and its salt of the present invention may have water of crystallization, and any of these hydrates are included within the scope of the present invention. The compound () of the present invention is produced, for example, by reacting an amide represented by the formula () with an imidazolidine-2-thione represented by the formula (), according to the following reaction formula. (In the formula, R, R ₁ and R ₂ have the above-mentioned meanings.) This reaction is preferably carried out in a suitable inert solvent, such as benzene, toluene,
xylene, acetone, methyl ethyl ketone, dimethyl formamide, dimethyl acetamide, dimethyl sulfoxide, acetonitrile, ether,
Tetrahydrofuran, dioxane, chloroform, water, etc. are used. The reaction temperature is -5°C to 100°C, preferably 20°C to
80, and the compound of the present invention can be obtained in high yield and purity by reaction for 1 to 6 hours. In order to obtain the free compound of the general formula () from the hydrochloride thus obtained, a base, such as an inorganic base such as sodium hydroxide, potassium hydroxide, potassium carbonate, sodium carbonate, sodium bicarbonate, ammonia, etc. , pyridine, triethylamine, or other organic base. Also, to lead to other salts, the corresponding acids such as sulfuric acid, carbonic acid, nitric acid, hydrobromic acid, phosphoric acid, sulfonic acid, acetic acid, oxalic acid, tartaric acid, citric acid, malic acid, glutamic acid, aspartic acid The above-mentioned hydrochloride or free compound may be treated with eg. The compound of formula () used as a raw material in this method can be obtained by, for example, reacting diketene () with anilines () to form a compound of formula () according to the following reaction formula, which is then converted into sulfuryl chloride. [Chemical Abstracts]
Abstracts) 19 , 43 (1925); 74 , 42102t (1970)
]
Alternatively, it can be produced by chlorination with chlorosuccinimide or the like. (In the formula, R has the above-mentioned meaning) In addition, another raw material compound () is, for example, Organic Synthesis (Org.Synth.),
It is produced by the following method according to the method described in Coll., page 3394. [Effect] Next, the pharmacological effects of the compound of the present invention () and its salt will be explained. Test Example 1 Effect on in vitro plaque-forming cell response using mouse splenocytes: 1 x 10 ⁷ BALB/C mouse splenocytes were injected with sheep red blood cells (1 x 10 ⁶ ) and test compound (0.2 or 1 μg/
RPMI−1640 containing 10% fetal bovine serum (ml)
Cultured in a CO ₂ incubator (37°C) for 5 days in medium [Mischell, R.
I) et al.; Journal of Exposure Medicine (J.Exp.Med.) 126:423 (1967)
], the number of plaque-forming cells that appear is determined by the Jerne and Nordin method.
method [Science 140:405 (1963)]
It was measured with The results are shown in Table 1. [Table] For levamisole to show enhancing activity, 20 μg/ml is required.
In this test requiring different concentrations, the compounds of the present invention showed clear activity at concentrations as low as 0.2 to 1 μg/ml. On the other hand, no obvious activity was observed in Comparative Compounds 1 and 2. Test Example 2 Effect on in vitro lymphocyte blastogenesis using mouse splenocytes or thymocytes: BALB/C mouse splenocytes (1 x 10 ⁵ cells) or thymocytes (2 x 10 ⁵ cells) Mitogen (ConA: 2.5 μg/ml or LPS: 10 μg/ml) and test compound (1 μg/ml) were incubated in RPMI-1640 medium (0.2 ml) containing 5% fetal bovine serum in a CO ₂ incubator (37°C). ) and cultured for 48 hours. then
0.5 μCi of ³ H-thymidine was added and cultured for an additional 18 hours, and the radioactivity of ³ H-thymidine incorporated into the cells was measured. The results are shown in Table 2. [Table] The compound of the present invention clearly increased the incorporation of ³ H-thymidine. Test Example 3 Effect on lymphocyte rejuvenation response when test compound was orally administered: Six BALB/C mice were used per group. The test compound was orally administered at 0.25 mg/Kg once a day for 5 days.
On the 6th day, the spleen was removed and splenocytes (2 x 10 ⁵ cells) were collected.
mitogen (ConA: 2.5μg/ml or
LPS (10 μg/ml) was cultured, and the lymphocyte priming reaction was examined. The culture conditions and the measurement of lymphocyte blastogenesis were conducted according to the method of Test Example 2. Table 3 shows the results.
Shown below. In this study, levamisole required administration of 2.5 mg/Kg/day to show its effect, but the compound of the present invention had a promoting effect equal to or greater than that of levamisole when administered at 1/10th the dose of 0.25 mg/Kg/day. showed that. [Table] Test example 4 Effect on delayed allergic reactions: 2 sheep red blood cells were subcutaneously placed on the backs of 1 group of 8 ddY mice.
⁸ ×10 cells were injected for sensitization. Four days after sensitization, 5 × 10 ⁷ sheep red blood cells were injected subcutaneously into the footpad of one side of the hind foot, and physiological saline was injected into the footpad of the opposite side, and the thickness of both footpads was measured with a micrometer 24 hours later to determine edema. The rate was calculated. The test compound was administered once a day starting 2 hours after sensitization.
Orally administered for 1 day. The results are shown in Table 4. The compound of the present invention significantly suppressed delayed allergic reactions when administered orally at 0.1 mg/Kg/day. [Table] Test Example 5 Effect on adjuvant arthritis: Sprague-Dawley
Adjuvant arthritis was induced by injecting 0.6 mg/0.1 ml of killed Mycobacterium tuberculosis suspended in liquid paraffin as an adjuvant into the splenic skin of one hind paw of eight male rats in one group. The compound of the present invention was orally administered once a day from 21 days after the adjuvant injection, and the spleen volume of the hind paw on the non-adjuvant-injected side was measured on the 7th and 10th day to determine the edema rate. The results are shown in Table 5. [Table] It was shown that the treatment effect was significantly lowered.
Test Example 6 Side effects and blood concentration: 300 mg/Kg of the test compound was orally administered to 4 Wistar rats once a day for 4 days, and changes in general symptoms were observed, as well as body weight and liver weight. The effects on serum cholesterol levels were investigated. Serum cholesterol was measured using a Baker cholesterol measuring kit with a Centrifikem autoanalyzer. Compound 1 was used as the compound of the present invention, Comparative Compounds 3 and 4 below were used as comparative compounds, and levamisole was used in some tests. In addition, blood concentrations of the test compounds were compared after one administration and after four days of administration. High performance liquid chromatography was used to measure blood concentration. Comparative compound 3 Comparative compound 4 (1) Effects on general symptoms No changes were observed in general symptoms in the Compound 1 and Comparative Compound 3 administration groups, but in the Comparative Compound 4 administration group, lacrimation, bleeding from the eyes, sedation, imbalance, and tremors occurred. A battle was seen. Half of the patients in the levamisole group died. (2) Effect on body weight Table 6 shows the body weight before and after continuous administration of the test compound. Compound 1 had no effect on body weight, but comparative compound 3 significantly reduced body weight. Levamisole significantly reduced body weight even when administered at 100 mg/Kg/day. [Table] (3) Effect on liver weight Table 7 shows the results obtained. Compound 1 had no significant effect on liver weight, whereas comparative compound 3 significantly increased liver weight. [Table] (4) Serum cholesterol The test results are shown in Table 8. Compound 1 had no significant effect on serum cholesterol, but
Comparative compounds 3 and 4 and levamisole significantly increased cholesterol levels. [Table] (5) Changes in blood concentration due to continuous administration Blood concentrations measured by sacrificing blood samples from animals at the 1st hour and 2nd hour, respectively, after a single administration and once a day for 4 days are shown. 9. The blood concentration of Compound 1 was close to the blood concentration after a single administration even after 4 days of administration, but the blood concentrations of Comparative Compounds 3 and 4 were significantly reduced by continuous administration. . [Table] [Effect] As is clear from the above test results, the compound of the present invention () has an excellent immunomodulatory effect, and therefore can be used as a prophylactic and therapeutic drug for immune diseases, such as rheumatoid arthritis, systemic lupus erythematosus, and collagen. It can be used for the treatment and prevention of chronic nephritis, autoimmune diseases such as autoimmune hemolytic anemia, immediate and delayed allergic diseases, malignant tumors, severe infections, and the like. The compounds of the present invention can be administered orally or parenterally (eg, intramuscularly, subcutaneously, intravenously, anally, or cutaneously) as such or in various dosage unit forms. The dosage forms include solid preparations such as tablets, sugar-coated tablets, film tablets, hard or soft capsules, troches, pills, granules, and powders; semi-solid preparations such as suppositories, patches, and ointments; and injections. , syrups, inhalants, emulsions, suspensions, and other liquid preparations. Although the compound of the present invention can be used alone as the above-mentioned preparation, it may also be combined with other medicinal ingredients such as non-steroidal analgesics, anti-inflammatory agents, etc. [Example] Next, reference examples and examples will be given and explained. Reference Example 1 2.5 g (0.02 M) of m-chloroaniline and a catalytic amount of pyridine were dissolved in toluene, and diketene was dissolved.
1.9g (0.022M) was slowly added dropwise at 50°C, and after the addition was completed, the mixture was heated under reflux for 3 hours. Ligroin was added under ice-cooling, and the precipitated crystals were collected, washed successively with ligroin and hexane, and dried under reduced pressure to obtain 3'-chloroacetoacetanilide. Example 1 (i) 2.1 g (0.01 M) of 3'-chloroacetoacetanilide obtained from Reference Example 1 was dissolved in diethyl ether, and 1.5 g (0.011 M) of sulfuryl chloride was dissolved.
was added dropwise at -5°C and stirred at -10 to -5°C for 30 minutes. The mixture was poured into ice water, neutralized with sodium hydrogen carbonate, extracted with toluene, and the organic layer was dried and concentrated. The residue was dissolved in methyl ethyl ketone and 4,4-dimethylimidazolidine-
1.3 g (0.01 M) of 2-thione was added, and the mixture was heated under reflux for 3 hours. The precipitated crystals were collected, recrystallized from inpropanol, and dried under reduced pressure at 120°C for 3 hours. Suspended in methyl ethyl ketone,
Heated under reflux for 20 hours, cooled, collected, washed with acetone, and dried under reduced pressure to obtain 3'-chloro-3,6,6
-Trimethyl-5,6-dihydroimidazo[2,1-b]thiazole-2-carboxyanilide hydrochloride (compound 1) 2.6 g (yield 72.2%)
I got it. PMR data ppmδ (DMSO−d ₆ ) 1.53
(6H, s, 6.6 (CH ₃ ) ₂ ), 2.53 (3H, s, 3-C
_H3 ) _, 4.27 (2H,s,5- CH2- ), 7.03-8.00
(4H, m, Aromatic protone), 10.80 (1H,
s, -NH- ). (ii) Obtained 3-chloro-3,6,6-trimethyl-5,6-dihydroimidazo[2,1-b]
Thiazole-2-carboxanilide hydrochloride
1.8g (0.005M) was dissolved in water, and a 20% aqueous potassium carbonate solution was added dropwise while stirring at room temperature. The resulting precipitate was collected and purified by washing with a large amount of water. This material was dried under reduced pressure and 3′-chloro-
3,6,6-trimethyl-5,6-dihydroimidazo[2,1-b]thiazole-2-carboxyanilide (melting point 172-173°C, milky white powder)
1.3g of was obtained. Example 2 (i) 2.1 g (0.01 M) of 4'-chloroacetoacetanilide obtained in the same manner as in Reference Example 1 was dissolved in diethyl ether, and 1.5 g of sulfuryl chloride was dissolved.
g (0.011M) was added dropwise at -5℃, -10 to -5
Stirred at ℃ for 30 minutes. The mixture was poured into ice water, neutralized with sodium bicarbonate, and extracted with toluene. The organic layer was dried and concentrated, the residue was dissolved in methyl ethyl ketone, 1.3 g (0.01 M) of 4,4-dimethyl-imidazolidine-2-thione was added, and the mixture was heated under reflux for 3 hours. The precipitated crystals were collected, washed with acetone, and dried under reduced pressure to give 4′-
Chloro-3,6,6-trimethyl-5,6-dihydroimidazo[2,1-b]thiazole-2
-Carboxanilide hydrochloride (compound 2) 3.4
g (yield 94.4%) was obtained. Melting point 264-268℃. (ii) Obtained 4'-chloro-3,6,6-trimethyl-5,6-dihydroimidazo[2,1-b]
Thiazole-2-carboxanilide hydrochloride
1.8g (0.005M) was dissolved in water, and a 10% aqueous solution of caustic soda was added dropwise while stirring at room temperature. The resulting precipitate was collected and purified by washing with a large amount of water. This material was dried under reduced pressure and 4′-chloro-
3,6,6-trimethyl-5,6-dihydroimidazo[2,1-b]thiazole-2-carboxyanilide (melting point 235-236°C, white powder)
Obtained 1.0g. Example 3 2'-chloro-4'-trifluoromethylacetoacetanilide obtained in the same manner as Reference Example 1
2.8 g (0.01 M) and 1.4 g (0.01 M) of N-chlorosuccinimide were suspended in carbon tetrachloride, a catalytic amount of benzoyl peroxide was added, and the mixture was heated under reflux for 1 hour. The reaction solution was washed with water, dried, and concentrated, and the residue was dissolved in methyl ethyl ketone, and 1.3 g (0.01 M) of 4,4-dimethylimidazolidine-2-thione was added.
was added and heated under reflux for 3 hours. The precipitated crystals were collected, recrystallized from inpropyl ether-ethanol, and dried under reduced pressure at 120°C for 3 hours to obtain 2'-
Chloro-4'-trifluoromethyl-3,6,6-
Trimethyl-5,6-dihydroimidazo[2,1
-b] Thiazole-2-carboxyanilide hydrochloride (compound 3) 2.5 g (yield 61.9%) was obtained. (Melting point 148-150℃) Example 4 4.3 g (0.01 M) of 3',4'-diiodoacetoacetanilide and 1.4 g (0.01 M) of N-chlorosuccinimide obtained in the same manner as in Reference Example 1 were suspended in carbon tetrachloride, and the catalytic amount of benzoyl peroxide was added thereto, and the mixture was heated under reflux for 1 hour. The reaction solution was washed with water, dried and concentrated, the residue was dissolved in methyl ethyl ketone, 1.2 g (0.01 M) of 4-methylimidazolidine-2-thione was added, and the mixture was heated under reflux for 3 hours. Collect the precipitated crystals, wash with acetone,
Dry under reduced pressure to obtain 3',4'-diiodo-3,6-dimethyl-5,6-dihydroimidazo[2,1-b]
4.8 g (yield: 85.7%) of thiazole-2-carboxyanilide hydrochloride (compound 4) was obtained. (melting point 278
~280℃) Example 5 2.5 g (0.01 M) of 3',4'-dichloroacetoacetanilide and 1.4 g (0.01 M) of N-chlorosuccinimide obtained in the same manner as in Reference Example 1 were suspended in carbon tetrachloride, and a catalytic amount of Benzoyl peroxide was added and the mixture was heated under reflux for 1 hour. The reaction solution was washed with water, dried, and concentrated, and the residue was dissolved in methyl ethyl ketone.
1.3 g (0.01 M) of 2-thione was added, and the mixture was heated under reflux for 3 hours. The precipitated crystals were collected, recrystallized from isopropyl ether-ethanol, and dried under reduced pressure.
Dry at 120℃ for 3 hours to obtain 3',4'-dichloro-3,
2.5 g (yield 64.1%) of 5,6-trimethyl-5,6-dihydroimidazo[2,1-b]thiazole-2-carboxyanilide hydrochloride (compound 5) was obtained. Melting point 240-245℃ Examples 6-38 Same as the above reference examples and Examples 1-5 [Table] [Table]

Claims (1)

[Claims] First-order general formula () (wherein, R is a phenyl group, [Formula] (R ₃ is a chlorine atom, bromine atom, iodine atom, lower alkyl group, lower alkoxy group, or nitro group) or [Formula] (R ₄ is a halogen atom, Lower alkoxy group or trifluoromethyl group,
R ₅ represents a halogen atom, hydroxyl group, lower alkoxy group or trifluoromethyl group), and R ₁
and R ₂ are the same or different and represent a hydrogen atom or a lower alkyl group. A dimethyl-5,6-dihydroimidazo[2,1-b]thiazole-2-carboxanilide derivative or a salt thereof, represented by (the group _CH3 means being substituted at the 5- or 6-position).