JPH0557990B2 - - Google Patents

Description

[Detailed description of the invention]

[Field of Industrial Application] The present invention relates to a novel pyrimido[1,2-a]benzimidazole derivative having excellent physiological activities such as anticancer activity, immunomodulatory activity, and antiallergic activity, and a method for producing the same. be. [Prior Art] It has been known that pyrimidopyridine, which is a [2+4] adduct, is produced when 2-allylideneaminopyridine and haloketene are reacted [for example, Kato et al., Journal of Heterocytology]. Crit Chemistry (J.Heterocycl.
chem.) 21 , 407 (1984)]. [Problems to be Solved by the Invention] The present invention provides a novel pyrimido[1,2-a]benzimidazole derivative having excellent physiological activity, and the above reaction is carried out using an amino nitrogen-containing heterocycle. This is extended to reactions with specific Schiff bases. Specifically, a pyrimido[1,2-a]benzimidazole derivative was synthesized by the reaction of the Schiff base having the amino nitrogen-containing heterocycle with chloroketene or chlorophenylketene, and its physiological activity was examined. As a result, it was found to have anticancer effects in vitro. was discovered. [Means for solving the problem] The present invention is based on the general formula (): (In the formula, R represents hydrogen or a phenyl group.) A pyrimido[1,2-a]benzimidazole derivative represented by the following is provided. Furthermore, the present invention provides the general formula () A Schiff base represented by and the general formula (): The present invention provides a method for producing a pyrimido[1,2-a]benzimidazole derivative represented by the general formula (), which comprises reacting the derivative with a haloketene represented by the formula (2). In addition, R in formula ()
has the same meaning as expression (). The compound of the present invention is produced by such a method, and the haloketene represented by the general formula () is
Since it is a highly reactive and unstable compound, the general formula (): (In the formula, R has the same meaning as in the formula ().) An acetyl chloride derivative represented by the formula (2) and an aliphatic tertiary amine, especially a trialkyl (1 to 3 carbon atoms) amine or 1,8-diazabicyclo[5,
4,0]-7-undecene (DBU) in a reaction system to produce the above-mentioned haloketene, which is preferably reacted with a Schiff base represented by the general formula (). Specifically, the anhydride 1 of the Schiff base of formula (),
Add trimethylamine and anhydrous N,N-dimethylformamide (DMF) solution to the 2-dimethoxyethane (DME) suspension. Next, an anhydrous DME solution of the acetyl chloride derivative of formula () is gradually added to the solution under stirring under salt-ice cooling (-15 to -5°C), and the mixture is reacted at room temperature for 3 to 20 hours. In addition, the raw material Schiff base was prepared by Hahn et al. (V.
Hahn et al) Arhiv.Kem. 26 , 21 (1954) and Sakamoto et al.
Bulletin (Chem.Pharm.Bull.) 24 , 2532
(1976) and other methods. [Effects of the Invention] The pyrimido[1,2-a]benzimidazole derivatives of the present invention have excellent physiological activities such as anticancer activity, immunomodulatory activity, and antiallergic activity, and can be used as is or pharmaceutically acceptable. It can be used in any form, such as liquid, powder, capsule, or granule, together with a carrier. EXAMPLES Hereinafter, the present invention will be explained in detail with reference to Examples, but the present invention is not limited thereto. [Example] Example 1 Schiff base (2.51
g, 0.01 mol) was suspended in anhydrous DME (160 ml),
Triethylamine (1.52g, 0.015mol) and anhydrous
DMF (10ml) was added. A solution of chloroacetyl chloride (1.36 g, 0.012 mol) in anhydrous DME (10 ml) was added dropwise to the solution under stirring under salt-ice cooling (-15 to -10° C.). After completion of the dropwise addition, the mixture was returned to room temperature and stirred for 3 hours, then the solvent was distilled off under reduced pressure, the resulting residue was dissolved in chloroform (300 ml), and the chloroform layer was washed with water (100 ml x 3). After drying over anhydrous sodium sulfate, the solvent was distilled off under reduced pressure. The obtained crystals were washed successively with acetone (50 ml) and ethanol (50 ml), and the washings were concentrated to obtain a crystalline residue. After washing with ether (200 ml), the crystals were recrystallized from acetone to obtain colorless needle crystals with a melting point of 299-301°C. Yield was 0.50g (17%). Table 1 shows the characteristic values of the obtained compound. Example 2 Schiff base (2.51
g, 0.01 mol) was suspended in anhydrous DME (180 ml),
Triethylamine (1.52g, 0.015mol) and anhydrous
DMF (10ml) was added. Chlorphenylacetyl chloride (2.27 g, 0.012 mol) was added to the solution in anhydrous DME (10
ml) solution was added dropwise. After dropping, return to room temperature16
After stirring for an hour, the solvent was distilled off under reduced pressure, the resulting residue was dissolved in chloroform (300 ml), and the chloroform layer was washed with water (100 ml x 3). After drying over anhydrous sodium sulfate, the solvent was distilled off under reduced pressure. The obtained crystals were washed with acetone (50 ml) and then recrystallized from ethanol to obtain colorless needle crystals with a melting point of 310°C or higher. Yield was 0.78g (21%). Table 1 shows the characteristic values of the obtained compound.

【table】

[Table] Example 3 The cancer cell proliferation suppressive effects of the compounds prepared in Examples 1 and 2 were investigated using K562, a human leukemia cell. Γ Materials and Test Methods Tumor cells: K562, a human leukemia cell, was used. Cell culture: 10% fetal bovine serum, 2mM L-glutamine, 100U of penicillin/antibiotics
ml, containing streptomycin 100mg/ml
Tumor cells cultured using RPM11640 (complete medium) were adjusted to 5 x 10 ⁵ cells/ml with fresh medium, and 0.2 ml (1 ×
10 ⁴ cells/well) and add the sample to the final concentration.
The concentration was adjusted to 10 ^-4 to 10 ^-8 M and cultured in an incubator at 37° C. and 5% CO ₂ for 3 days. Preparation of sample: Dissolve the sample in complete medium or dimethyl sulfoxide (DMSO) to 10 ^-2 M, then dilute appropriately with complete medium to make a concentration 10 times the concentration to be tested. A 20μ aliquot was added to a microplate on which tumor cells had been seeded. ^3H -thymidine incorporation: ^3H -thymidine incorporation on the third day of culture
-Add 0.5μCi/10μ of thymidine to each well,
After 6 hours, use a cell harvester (Labo).
Mash) to collect cells onto filter paper, dry them, and then measure them using a liquid scintillation counter. Control drug: Adriacin (ADR,
It was tested in the same way as the specimen using Kyowa Hakko). Control: The amount of ³ H-thymidine taken up by untreated tumor cells was used as a control for the water-soluble sample (a control was taken for each sample, and the average excluding the highest and lowest values was used as the control value). A DMSO control for a DMSO-soluble specimen was prepared by adding a DMSO solution diluted to the same amount as that contained in the specimen solution at each concentration. ●Results When a biological activity test was conducted using the above method, ³ H-thymidine uptake was significantly inhibited at a concentration of 10 ^-4 M in human leukemia cells K562.
The effect was almost the same as that of the control drug Adriacin.

Claims (1)

[Claims] 1 General formula (): (In the formula, R represents hydrogen or a phenyl group.) A pyrimido[1,2-a]benzimidazole derivative represented by: 2 Formula (): A Schiff base represented by and the general formula (): (In the formula, R represents hydrogen or a phenyl group.) General formula () characterized by reacting with a haloketene represented by: A method for producing a pyrimido[1,2-a]benzimidazole derivative represented by 3 In the reaction system, the haloketene represented by the general formula () is converted to the general formula (): (In the formula, R has the same meaning as above.) The manufacturing method according to claim 2, which is produced by the reaction of an acetyl chloride derivative represented by the following formula with an aliphatic tertiary amine.