JPS62145084A - Imidazo(4,5-b)pyridine derivative - Google Patents

Abstract

NEW MATERIAL:A compound expressed by formula I (R represents H, halogen atom or 1-3C alkyl). EXAMPLE:2-[2-(3,5-Dimethyl-4-methoxy)pyridylmethylthio]-6-bromoimidazo [4,5-b] pyridine. USE:A remedy for gastric and duodenal ulcers. PREPARATION:A 2-mercaptoimidazopyridine derivative expressed by formula II (example; 2-mercaptoimidazo[4,5-b]pyridine, etc.) is condensed with a pyridine derivative expressed by formula III (X represents Cl or Br) (example; 2- chloromethyl-3,5-dimethyl-4-methoxyphridine hydrochloric acid, etc.) in a reaction solvent using a base to obtain a 2-[2-(3,5-dimethyl-4-methoxy) pyridylmethylthio]imidazopyridine derivative, which is oxidized with an oxidizing agent (preferably m-chloroperbenzoic acid) in the presence of the reaction sol vent.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to novel imidazo[4,5-'b]pyridine derivatives. The imidazo[4,5-b]pyridine derivative of the present invention has an action of specifically inhibiting the activity of potassium ion-dependent adenosine triphosphatase [hereinafter abbreviated as (H"10K") ATPase], and It is also expected to be a therapeutic agent for duodenal ulcer.

In recent years, in the pathophysiology of gastric or duodenal ulcers, hydrochloric acid production within the gastric endoplasmic reticulum vesicles has been implicated (H+K >
The behavior of ATPase has attracted attention, and the presence or absence of inhibition of the activity of this enzyme has come to be used as an indicator for anti-ulcer agents [Gastroenterology].
) Vol. 1, p. 420 1943; Vol. 73, p. 921
1977]. 5-Methoxy-2-[2-(4-
Methoxy-3,5-dimethyl)pyridylmethylsulfinyl]benzimidazole (hereinafter abbreviated as omeprazole) is known [JP-A-54-141783:
Briti 1” Medical Journal (Briti
287
Volume 12, 1983. On the other hand, imidazo[4,5-
b] Among pyridine derivatives, compounds containing a pyridine skeleton via a sulfur atom in the 2-position side chain include 2-(2-substituted pyridylmethylthio)imidazo [4,51], which is suggested to have a gastric acid secretion suppressing effect. ]Pyridine compound (
JP-A No. 50-116474), and 2-(2-pyridylmethylthi'A)imidazo[4,5-bl pyridine (hereinafter tentatively named compound A), which exhibits tuberculosis inhibiting action and antibacterial action. British Patent No. 1234058) has been reported.

Problems to be Solved by the Invention However, Japanese Patent Application Laid-open No. 116474M/1983 states that:
2-(2-substituted pyridylmethylthio)imidazo[4,5
-b] There are no specific examples of the pyridine compound described, and its suppressive effect on gastric acid secretion has not been proven through specific experiments. Furthermore, regarding compound A, British Patent No. 12340
Publication No. 58@ makes no mention of its inhibitory activity against (H+K)ATPase. Therefore, the present inventors prepared 2-[2-(3,5-dimethyl-
4-methoxy)pyridylmethylthio]imidazo[4,5
-b] Pyridine (hereinafter tentatively referred to as Compound B) was synthesized and a follow-up experiment was conducted to determine the inhibitory activity against ATP-Arbi (1-10+), and it was found that these two compounds had no such activity. found.

The present inventors used omeprazole as a comparative compound and (H
+K ・) As a result of intensive searches for substances that inhibit ATPase activity, we found that the side chains of compounds A and B, pyridylmethylthio and (3,5-dimethyl-4-methoxy)pyridylmethylthio groups, were replaced by (3,5-dimethyl-4-methoxy)pyridylmethylthio groups. An imidazo[4,5-b]pyridine derivative converted into a dimethyl-4-methoxy)pyridylmethylsulfinyl group has a remarkable (H+K) ATPase activity inhibitory effect that cannot be expected from compounds A and B, and its inhibitory effect The present invention was developed based on the discovery that omeprazole is significantly more effective than omeprazole.

Means for Solving the Problems According to the present invention, the following general formula [I] (wherein R is a hydrogen atom, a halogen atom, or a carbon number of 1 to 3
represents a straight chain or branched alkyl group. ) Imidazo[4,5-b]pyridine derivatives are provided.

The imidazo[4,5-b]pyridine derivative represented by the general formula [I] also includes the tautomer represented by the following general formula [■"1 (wherein, R has the same meaning as above)" be done.

In the general formulas [E] and [■°], the halogen atom represented by R includes a chlorine atom, a bromine atom, or an iodine atom. Similarly, straight chain or branched alkyl groups having 1 to 3 carbon atoms include methyl group, ethyl group,
Examples include n-propyl group and isopropyl group.

Imidazo [4] represented by the general formula [I] and [■°1]
, 5-b] pyridine derivative (hereinafter simply referred to as the compound of the present invention [I
] and abbreviation V) are 2-[2-(3,5-dimethyl-4-methoxy)pyridylmethylthio]imidazo represented by the following general formula [II] (wherein R has the same meaning as above). Pyridine derivative,
It can be produced by oxidation using an oxidizing agent in the presence of a suitable reaction solvent. The reaction rate is 2-[2
-(3,5-dimethyl-4-methoxy)pyridylmethylthio]imidazopyridine derivative [I] The oxidizing agent is used in a molar amount of 1.0 to 1.3 times. Examples of the oxidizing agent that can be used include peroxides such as m-chloroperbenzoic acid, perbenzoic acid, and peracetic acid, and m-chloroperbenzoic acid is preferred because of its high stability. Suitable reaction solvents include, for example, chloroform or TeI.
Examples include halogenated hydrocarbons such as lachloroethane, alcohols such as methanol, ethanol, propatool or butanol, or a mixture of two or more of these.

However, in terms of selectivity and yield in the oxidation reaction, chloroform or a mixture of chloroform and methanol is particularly preferred. Reaction temperature is -70~30°C1
The temperature is preferably in the range of -20 to 10'C, and the reaction time is about 1 minute to 24 hours, preferably about 5 minutes to 1 hour.

The above-mentioned 2-[2-(3,5-dimethyl-4-methoxy)pyridylmethylthi primary imidazopyridine derivative [n]
is a 2-mercaptoimidazopyridine derivative represented by the following general formula [II[] (wherein R has the same meaning as above),
It can be produced by condensing a pyridine derivative represented by the following general formula [IV] (wherein, X represents a jn atom or a bromine atom) using a base in a reaction solvent. The reaction ratio is 2-mercaptoimidazopyridine derivative [1], equimolar amount of pyridine derivative [1v], and 2.0 molar amount of base.
~3.0 times the molar amount.

Examples of bases that can be used include helium hydrogen carbonate, sodium carbonate, potassium carbonate, sodium hydroxide, and potassium hydroxide.

Examples of the reaction solvent include alcohols such as methanol, ethanol, propatool or butanol, aprotic polar solvents such as dimethylformamide or dimethyl sulfoxide, water, or a mixture of two or more thereof. Reaction is 10-200'
C1 Preferably, the temperature is 60 to 80°C, and the reaction time is about 1 minute to 12 hours, preferably about 5 minutes to 4 hours. The 2-mercaptoimidazopyridine derivative [In], which serves as a starting material, can be prepared by a known method, for example, in the Journal of Organic Chemistry (Journal of Organic Chemistry).
fOrganic Chemistry) Volume 24
It can be produced by a method similar to that described in 1959, page 1455.

Actions and Effects of the Invention The inhibitory activity of the compound of the present invention [II against (H+K) ATPase and the suppressive action of gastric acid secretion will be described in detail below.

The experiment was conducted using a representative example of the compound of the present invention [II (hereinafter abbreviated as test compound).

(i) (H++K''> ATPase inhibitory activity The experiment of the (H + K > ATPase inhibitory activity of the present compound [II) was conducted using a solution containing 300 to 500.i of the M element in terms of protein amount. Add the test compound and add this to 35-3
After reacting at 7°C for 5 to 30 minutes, (H
+K > This was performed by measuring the residual activity of ATPase. The test compound was dissolved in methanol or ethanol in advance, and added so that the concentration of the test compound in the reaction system was 1×10 −3 mol.

(H+K) ATPase was obtained from fresh gastric fundic glands of edible pig mass (Og) using the method of Saccoman et al. [The Journal of Biolo
251%, No. 23, p. 7690, 1976]. (H + K > The residual activity of ATPase can be determined by mixing magnesium chloride and potassium chloride with the obtained reaction solution, adding adenosine triphosphate, and heating at 37°C for 5 to 50 minutes.
The enzymatic reaction was carried out for 15 minutes, and then the liberated inorganic phosphoric acid was determined by colorimetric loss using an ammonium molybdate reagent. The initial concentrations of magnesium chloride, potassium chloride, and adenosine triphosphate were 2 mmolar, 20 mmolar, and 2 mmolar, respectively. Colorimetry was performed at a wavelength of 360-400 nm. In addition, (1-1+K)ATP when no test compound was added
The residual activity of Aase was also measured in the same manner as above.
This was used as a control experiment.

The results are shown in Table 1. In the table, the inhibitory effect is 1 in the control experiment.
The difference between the measured value and the first measurement when the test compound was added was determined, and this was expressed as a percentage of the measured value in the control experiment. In addition, the same table shows the <H0K>AT of omeprazole and compounds A and B measured in the same manner as above.
Pase inhibitory activity is also shown for comparison. However, the concentration of compound A is 1×10-molar, and the concentration of compound B is 2.
5X 10-3 molar concentration.

(Leaving space below) Table 1 (Continued) Table 1 (Continued) (ii) Suppressive effect on gastric acid secretion Experiments on the suppressive effect on gastric acid secretion by the compound [I] of the present invention were as follows:
- After an overnight fast, 1 to 100
mg/to! The test was performed by administering 1 of the test compound into the duodenum, and measuring the total acidity of the gastric fluid in each rat after 4 hours had elapsed. The test compound was administered by suspending it in a 0.5% carboxymethylcellulose aqueous solution. Gastric juice was collected by sacrificing each rat and performing laparotomy. The total volume of gastric juice was measured using a 0.1N aqueous sodium hydroxide solution.
It was determined by titrating the gastric juice until the pH value reached 7.0. As a control experiment, the total acidity of gastric fluid in the non-administered group was also measured in the same manner as above. The inhibitory effect on gastric acid secretion was evaluated based on the dose Wi<mFl/Kg- (hereinafter abbreviated as ED5o) required to suppress gastric acid secretion, that is, the total acidity of gastric juice by 50%. The ED5o value was calculated by first taking the difference in total acidity between the non-administration group and each test compound administration group, dividing this by the total acidity of the non-administration group to calculate the inhibition rate, and then plotting based on this inhibition rate. Determined from dose-effect curve. The results are shown in Table 2. In addition, the ED5011fi of omeprazole and Compound B, which were determined in the same manner as described above, are also listed in the same table for comparison.

(As is clear from Tables 1 and 2 in Table 2 below, the compounds of the present invention [
I] has remarkable (H+K) ATPase inhibitory activity and is recognized to strongly suppress gastric acid secretion. Therefore, the compound [I] of the present invention can be expected as a therapeutic agent for gastric or duodenal ulcers.

The present invention will be further explained with reference examples and examples.

Reference example 1 (method for producing compound B) 2-mercaptoimidazo[4,5-b]pyridine 1.5
1y (0.01 mol), 2-chloromethyl-3゜5-
Dimethyl-4-methoxypyridine hydrochloride 2.22ci (
0.01 mol)'' and potassium hydroxide 1.20 L3 (0
,02 mol), water-ethanol (capacity 1:14)
The mixture was mixed and dissolved in a liquid mixture, and heated under reflux for 1 hour. This reaction solution was poured into ice water, extracted with 400r111 of ethyl acetate, dried over anhydrous sodium sulfate, and then dried under reduced pressure. When the obtained residue was recrystallized from a chloroform-methanol mixture, 2-[2-(3,5-dimethyl-4-methoxy)pyridylmethylthio]imidazo[4°5] having a melting point of 165-170°C was obtained. -b] 1q of 2.359 colorless crystals of pyridine (yield 7863%).

1 Boiled ■2 Ethanol 1107 containing 0.80 g (0.02 mol) of sodium hydroxide! , 1.65 g of 2-mercapto-7-methylimidazo[4,5-b]pyridine (0,0
1 mol) and 2-chloromethyl-3,5-dimethyl-4
-Methoxypyridine hydrochloride (2.229 < o, oi mol) was added and heated under reflux for 3 hours. After cooling in the air, insoluble matter in the reaction solution was filtered off, and the filtrate was concentrated under reduced pressure. This residue was dissolved in 400 ml of chloroform, washed with water, and the chloroform layer was dried over anhydrous sodium sulfate and then dried under reduced pressure. When the obtained residue was purified by silica gel column chromatography using chloroform as a developing solvent, 2-[2-(3,5-dimethyl-4-methoxy)pyridyl having a melting point of 174-176°C was obtained. methylthio]-7-methylimidazo[4,5
-b] Colorless crystals of pyridine 2.229 (yield 70.7%)
) was obtained.

2-Mercapto-7-methylimidazo[4,5-bl pyridine (0:01 mol) was converted into the corresponding 2-mercapto[.
The following six compounds were produced in substantially the same manner as described above, except that one imidazopyridine derivative [In] (0.01 mol) was used.

2-[2-(3,5-dimethyl-4-methyl-xy)pyridylmethylthio]-6-methylimidazo[4゜5-b
] Pyridine; melting point 179-180°C02-[2-(3
,5-dimethyl-4-methoxy)pyridylmethylthio]
-5-methylimidazo[4°5-b]pyridine: melting point 1
66-167°C02-[2-(3,5-dimethyl-4
-methoxy)pyridylmethylthio]-7-nitylimidazo[4°5-b]pyridine; melting point 169-170°C.

2- [2-(3,5-dimethyl-4-methoxy)pyridylmethylthio]-6-nitylimidazo[4°5-b]
Pyridine; melting point 172-174°C.

2-[2-(3,5-dimethyl-4-methoxy)pyridylmethylthio]-7-itupropylimidazo[4,5
-b] Pyridine: Melting point 151-153°C02-[2-
(3,5-dimethyl-4-methoxy)pyridylmethyldio]-5-n-propylimidazo[4,5-b]pyridine: Melting point 153-155°C6 Reference Example 3 Potassium hydroxide 1°68s (0, To 10 (7!) methanol containing 0.03 mol), 1.86 cJ (0.
01 mol) and 2-bromomethyl-3,5-dimethyl-
4-Methoxypimo (0.01 mol) was added, and the mixture was heated and centrifuged for 20 minutes. Add this reaction solution to 3007 ml of ice water! injected into 500 ml of chloroform
The extract was extracted with m1, dried over anhydrous potassium carbonate, and then dried under reduced pressure. When the obtained residue was recrystallized from a mixture of ethyl acetate and hexane, 2-[2-(3,5-dimethyl-4-methoxy) having a melting point of 221 to 223°C was obtained.
pyridylmethylthio]-5-chloroimidazo[4,5-
b] Colorless crystals of pyridine 2.129 (yield 63.3%
) was obtained.

Except that 2-mercapto-5-chloroimidazo[4,5-b]pyridine (0,01 mol) was changed to the corresponding 2-mercaptoimidazopyridine-derived aqueous [I[1] (0,01 mol), respectively. were treated in substantially the same manner as described above to produce the following three compounds.

2-[2-(3,5-dimethyl-4-methoxy)pyridylmethylthio]-7-chloroimidazo[4°5-b]
Pyridine; melting point 203-206°C (recrystallized from ethyl acetate-hexane mixture).

2-[2-(3,5-dimethyl-4-methoxy)pyridylmethylthio]-6-promoimidazo[4°5-b]
Pyridine; melting point 220-222°C (recrystallized from ethyl acetate).

2- [2-(3,5-dimethyl-4-methoxy)pyridylmethylthio]-6-iodoimidazo[4°5-b]
Pyridine; melting point 193-196°C (recrystallized from methanol).

Example 1 2-[2-(3,5-dimethyl-4) produced in Reference Example 1
-methoxy)pyridylmethylthio]imidazo[4,5-
b] Pyridine (compound [3) 1.509 (0,005
mol) was dissolved in 107 ml of a chloroform-methanol (volume ratio: 100 molar) mixture, 1.04 g < 0.006 mol) of m-chloroperbenzoate was gradually added at 0 to 5°C, and the solution was dissolved at the same temperature. Stirred for 15 minutes. In this reaction solution,
Ethyl ether was injected at 0 to 5°C until crystals precipitated, and the precipitated crystals were read. When the crystals were washed with an appropriate amount of ethyl ether and recrystallized from a chloroform-ethyl ether mixture, 2-[2-(3,5-dimethyl-4-methoxy)pyridylmethylsulfinyl] was obtained.
Colorless crystals of imidazo[4,5-b]pyridine 1.219
(yield 76.6%) was obtained. Melting point was 158-160'
It was C.

Infrared absorption spectrum (KBr, cm-1): 10
50 (S=O) Elemental analysis value (C15H16N402 S and LT): Theoretical value (%); C, 56,94H, 5,10N, 17.7
1 Actual value (%); C, 57,05H, 5,21N, 1
7.68 Example 2 2-[-2-(3,5-dimethyl-
1.57 g (0,005
mol) in 120M chloroform, and add m-chloroperoxychloride 1. o49 (0,006 mol) from 0 to
The mixture was gradually added at 5°C and stirred at the same temperature for 10 minutes. Add 80 d of 5% sodium carbonate aqueous solution to this reaction solution.
The mixture was poured and mixed at °C, and the chloroform layer was separated.

This chloroform layer was dried over anhydrous sulfur and then dried under reduced pressure. The resulting residue was washed with an appropriate amount of ethyl ether and then recrystallized with methanol.
2-[2-(3゜5-dimethyl-4-methoxy)pyridylmethylsulfinyl]-7-methylimidazo[4,
5-b] Colorless crystals of pyridine 1.079 (yield 64,
8%).

The melting point was 185-190'C.

Infrared absorption spectrum 1-1 (KBr, cm”): 1040
(S=O) Elemental analysis value (as C16H18N402S): Theoretical value (%); C, 58, 16H, 5, 49N, 16.96
Actual value (%); C, 58,08H, 5,52N, 16
．． 882-[2-(3,5-dimethyl-4-methoxy)py1nodylmethyldiokho7-methylimigzo14゜5-b]pyridine (0,005 mol) was added to the corresponding 2-
[2-(3,5-dimethyl-4-methoxy)pyridylmethylthio]imidazopyridine 2>1 [II] (0,0
The following Examples 3 to 8 were processed in almost the same manner as described above, except that the reaction temperature, time, etc. were slightly changed.
The compound was produced.

Example 3 2-[2-(3,5-dimethyl-4-methoxy)pyridylmethylsulfinyl]-6-methylimidazo[4,
5-bl pyridine.

Colorless crystals; yield t369 (yield 82.4%) melting point: 15
8-163°C (recrystallized with methanol) Infrared absorption spectrum (KBr, cm-1): 1040 (S=O
) Elemental analysis value (as C16H18N402S): Theoretical value (%); C, 58, 16H, 5, 49N, 16.96
Actual value (%); C, 58, 24H, 5, 40N, 18
．． 99 Example 4 2-[2-(3,5-dimethyl-4-methoxy)pyridylmethylsulfinyl]-5-methylimidazo[4,
5-b] pyridine.

Muyuri product; yield t, 23 g (yield 74.5%) Melting point:
165-168°C (recrystallized with ethyl acetate) Infrared absorption spectrum (KBr, cm""): 1050 (S=O
) Elemental analysis value (as C16H18N402S): Theoretical value (%); C, 58, 16H, 5, 49N, 18.96
Actual value (%); C, 58, 12H, 5, 41N, 17
．． 06 Example 5 2-[2-(3,5-dimethyl-4-methoxy)pyridylmethylsulfinyl]-7-ethylimidazo[4,
5-b] pyridine.

Two colorless crystals 1.33 q (yield 77.3%) Melting point: 173-177°C (recrystallized with methanol) Infrared absorption spectrum (KBr, cm''>: 1040 (S=
O) Elemental analysis value (as C17H2oN402S): Theoretical value (%); C, 59,28H, 5,85N, 16.27
Actual value (%); C, 59, 35H, 5, 79N, 16
．． 18 Example 6 2-[2-(3,,5-dimethyl-4-methoxy)pyridylmethylsulfinyl-6-ethylimidazo[4
,5-b]pyridine.

Pale yellow glassy substance; yield 1.259 (yield 72.7%)
) Infrared absorption spectrum (KBr, cm”>: 104
0 (S=O) Elemental analysis value (C1□H2゜N4o2s and shite): Theoretical value (%); C, 59,28H, 5,85N, 16.27
Actual measurement fa (%); C, 59,44) -1,5°99N,
16°11 Example 7 2-[2-(3,,5-dimethyl-4-methoxy)pyridylmethylsulfinyl]-7-itsuprobylimidazo[4,5-b]pyridine.

Colorless crystals; yield 1.319 (yield 73.2%) melting point:
162-167°C (recrystallized with methanol) Infrared absorption spectrum (KBr, cm-'): 1040 (S=O
) Elemental analysis value (as C18H22N4o2S) Bitheoretical value (%); C, 60, 31H, 6, 19N, 15.63
Actual value (%); C, 60, 52H, 5, 98N, 15
．． 44 Example 8 2-[2-(3,'5-dimethyl-4-me-1-xy)pyridylmethylsulfinyl]-5-n-propylimidazo[4,5-b]copyridine colorless crystals; Yield 1.179 ( Yield 65.4%) Melting point:
143-148°C (recrystallized with methanol) Infrared absorption spectrum (KBr, cm"): 1050 (S=O) Elemental analysis value (as C18H22N402S): Theoretical value (%); C, 60, 31H, 6, 19N , 15.63
Actual value (%); C, 60, 17H, 6, 31N, 15
．． 73 Example 9 2-[2-(3,5-dimethyl-4) obtained in Reference Example 3
-methoxy)pyridylmethylthiocoke-chloroimidazo[4,5-b 1.679 (0,005 mol) of copyridine was mixed and dissolved in 250 ml of a chloroform-methanol (volume ratio 23:2) mixture, and m - Black perbenzoin M O,869 (0,005 mol) from -15 to
It was gradually added at a temperature of -10°C and stirred at the same temperature for 1 hour. The obtained reaction solution was poured into 100 d of 5% aqueous sodium carbonate solution at 5°C, and extracted with 400 ml of ethyl acetate at the same temperature. This ethyl acetate layer was dried over anhydrous sulfuric acid and thorium, concentrated under reduced pressure, and hexane was injected and mixed into the evaporated residual liquid until solid matter came out completely. When this precipitate was recrystallized from acetonitrile-ethyl ether mixture, 2-[2-(3,5-dimethyl-4
Pale yellow crystals of -methoxy)pyridylmethylsulfinyl]-5-chloroimidazo[4,5-t)]pyridine 1.
07cJ (yield 61.1%) was obtained. Melting point is 186-1
It was 90'C.

Infrared absorption spectrum (KBr, cm"): 1040
(S=O) Elemental analysis value (as C15H15CIIN402S):
Theoretical value [%); C, 51, 35H, 4, 31, N, 1
5.97 Actual value (%); C, 51,51H, 4,50N
, 16.092-[2-(3,5-dimethyl-4-methoxy)pyridylmethylthio]-5-chloroimidazo[
4°5-b Copyridine (0,005 mol) was converted into the corresponding 2-[2-(3,5-dimethyl-4-methoxy)pyridylmethylthio]imidazopyridine derivative [nl(0,0
Compounds of Examples 10 to 12 below were produced in substantially the same manner as described above, except that conditions such as reaction temperature and time were slightly changed.

2-[2-(3,5-dimethyl-4-methoxy)pyridylmethylsulfinyl]-7-chloroimidazo[4,
5-b] Copyridine colorless crystals; yield 1.159 (yield 65.7%) melting point: 1
72-177°C (recrystallized with ethyl acetate-hexane mixture) Infrared absorption spectrum (KBr, cm”): 1040
(S=O) Elemental analysis value (as C15H15CαN402S) Bitheoretical value (%); C, 51,35H, 4,31N, 15.
97 actual value (%); C, 51,28H, 4,23N,
15.94 Example 11 2-[2-(3,5-dimethyl-4-methoxy)pyridylmethylsulfinyl-6-bromoimidazo[4,
5-b] Copyridine colorless powder; yield 1.37 g (yield 69.2%) infrared absorption spectrum (KBr, cm-1>: 1040
(S=O) Elemental analysis value (as C15H15BrN4 o2S):
Theoretical value (%); C, 45, 58H, 3, 83N, 14
．． 18 Actual value (%); C, 45,47H, 3,92N,
14.24 Big dust cloud 2 2-[2-(3,5-dimethyl-4-methoxy)pyridylmethylsulfinyl]-6-iodoimidazo[4,
5-b Copyridine.

Pale yellow crystals; Yield i, iog (yield 49.8%) Melting point: 225 to 227°C (recrystallized from chloroform-ethyl ether mixture) Infrared absorption spectrum (KBr, cm''>: 1050
(S=O)

Claims (1)

[Claims] (1) General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (In the formula, R is a hydrogen atom, a halogen atom, or a carbon number of 1 to 3
represents a straight chain or branched alkyl group. ) An imidazo[4,5-b]pyridine derivative represented by: