JPH03236391A - Pyrrolo(1,2-c)imidazole derivative and production thereof - Google Patents

Abstract

NEW MATERIAL:A compound expressed by formula I [R<1> is H or acyl; R<2> is alkyl, allyl or OR<5> (R<5> is H, alkyl or aryl); R<3> and R<4> are H, alkyl or aryl]. EXAMPLE:6-Amino-2-methyl-1-methylcarbamoylimino-4-methyl-3-oxo-5-pyrro lo[1,2- c]imidazole expressed by formula II. USE:A raw material for fluorescent composition. PREPARATION:A compound expressed by formula III (e.g. 4-amino-5-cyano-2- methyl-pyrrole-3-carboxylic acid methyl ester) expressed by formula III is reacted with a compound (e.g. methylisocyanate) expressed by the formula R<4>NCO in the presence of a base (e.g. pyridine), preferably in an organic solvent at ambient temperature to 120 deg.C for 10 min to several hr to close a ring.

Description

Detailed Description of the Invention [Industrial Application Field] 4 is the same as above The present invention relates to a novel pyrrolo(1,2-c]imidazole conductor. The compound of the present invention has the possibility of bioactive ability. , which exhibits fluorescence, is expected to be used in a variety of ways.

[Conventional technology]

I-imino-3-oxo-pyrrolo(1,2-c) imidazoles are considered to be interesting nitrogen-containing heterocycles, but there is only one example of a compound as an intermediate for the pyrrolo(1,2-c) hydantoin platform. It is only known, and its production method is obtained by reacting phenyl isocyanate with a product obtained by shortening the thiocarboxa at the α-position by reacting an unsubstituted pyrrole with ethoxycarbonyl isothiocyanate. (E, P, Papadopoulas+J, Or
(G, Chem, +i 667 (1973)) However, in this production method, the raw material is limited to unsubstituted pyrrole, which not only cannot be used for the production of compounds with various substituents, but also inevitably Accompanied by by-product acids.

[Problems to be Solved by the Invention] The present inventors have investigated a method for producing a 1-imino-3-oxo-pyrrolo[1,2-〇]imidazole derivative that is completely different from conventional methods.

[Means to solve the problem]

As a result of intensive studies on the reaction between 2-cyanovirols and isocyanates, the present inventors have efficiently obtained the desired 1-ino-3-oxopyrrolo(1,2-c) imidazole derivatives, and also some of these. was found to be a fluorescent substance.

That is, the present invention provides: (1) - Formula [wherein R1 represents a hydrogen atom or an acyl group, Rz represents an alkyl group, an aryl group, or ○R8 (R3 represents a hydrogen atom, an alkyl group, or an aryl group] R1 represents a hydrogen atom, an alkyl group, or an aryl group, and R4 represents a hydrogen atom, an alkyl group, or an aryl group.

(2) - A compound represented by the formula (in which R', R'', and R3 have the same meanings as above) and the general formula R'NGO (III) (in the formula, R4 has the same meanings as above). General formula (where RI, R", R3, and R' are the same as above; I
Shows K taste. ) is a method for producing a compound represented by

The reaction was carried out in an organic solvent in the presence of a base at room temperature to 120 °C for 10
It lasts from minutes to hours.

All aprotic solvents can be used as the solvent, but preferably organic bases such as pyridine and quinoline, ketones, acetonitrile, DMF, DM
Aprotic polar solvents such as SO and halogenated hydrocarbons such as chloroform can be used.

As the base, organic bases such as pyridine and quinoline can be used, which also serve as reaction solvents, and triethylamine, DBU, etc. can also be used.

The molar ratio is 2 incyanate to 1 mole of pyrrole.
~25 mol, and the base is used in a catalytic amount to a large excess amount.

After the reaction is completed, the desired product can be obtained by conventional treatment.

The structure of the compound was determined from elemental analysis, IR, NMR, M2, etc.

Among the compounds of the present invention, compounds in which R4 is a hydrogen atom have tautomers.

〔Example〕

Next, the present invention will be explained in more detail with reference to Examples.

Example 1 6-Amino-2-ethyl-1-ethylcarbamoylimino-3-oxo-4-tity-5-pyrrolo (L2-c
) Imidazole is methyl carboxylate (compound number 2):
t Mix 1.8 g of methyl 4-amino-5-cinano 2-methyl-3-pyrrolecarboxylate with 1 d of pyridine, add 1.7 g of ethyl isocyanate while stirring, and add 1.8 g of methyl 2-methyl-3-pyrrolecarboxylate.
The reaction mixture was heated at °C for 2 hours and allowed to warm to room temperature, and the precipitated yellow crystals were filtered and thoroughly washed with benzene. Recrystallization from acetone-0-hexane gave 2.2 g of yellow crystals. Yield 68%, mp147-149'C1
The elemental analysis values were determined as follows.

Analysis value Calculated value C: 52.44% 52.33%H:
5.89 5.91N: 21.
72 21.80 more IR, NMR, M
From the spectrum results, the obtained crystals are 6-amino-
It was identified as methyl 2-ethyl-1-ethylcarbamoylimino-3-oxo-4-methyl-5-pyrrolo(1,2-c)imidazolecarboxylate.

Example 2 6-amino-2-methyl-1-methylcarbamoylimino-4-methyl-3-oxo5-pyrrolo(1,2-c
) Imidazole (Compound No. 1I CH.

7.2 g of methyl 4-ξ)-5-cyano-2-methyl-virol-3-carboxylate was mixed with 30 jd of pyridine, and 5.5 g of methyl isocyanate was added at room temperature with stirring. The internal temperature rose to 50°C. When the heat generation subsided, the reaction temperature was raised to 80° C. and heating was performed for 1 hour. Thereafter, the mixture was cooled to room temperature, and the precipitated yellow crystals were filtered and thoroughly washed with benzene to obtain 8.4 g of a yellow product.

The filtrate was concentrated and washed with methanol to obtain 2 g of a yellow product. The primary crystals and secondary crystals were mixed and recrystallized with acetone-〇hexane to obtain yellow crystals of IQg.

Yield 85.5%, mp 200-202°C Example 3 6-amino-5-benzoyl-2-ethyl-1-ethylcarbamoyl, 3-oxo4-methyl, pyrrolo(
1,2-c) Imidazole (Compound No. 7): Dissolve 0.25 g of pyrrole in 5d of pyridine, add 0.16 g of ethyl isocyanate at room temperature, and then reduce the reaction temperature to 90°C.
It was heated to °C and stirred for 30 minutes. After the completion of the reaction, pyridine was distilled off under reduced pressure, and the resulting residue was purified by silica gel chromatography (benzene-acetic acid ethyl 9:1) to obtain 0.2 g of the desired product as yellow crystals. Yield 50%, mp 176-17
7.5°C Example 4 Methyl 6-acetylamino-2-ethyl-I-ethylcarbamoylimino-3-oxo-4-methyl 5-pyrrolo[1°2-〇]imidazolecarboxylate (Compound No. 8
): t 3-Amino-2-cyano-5-methyl-4-benzoylt 0.91 g of methyl 4-acetylamino-5-cyano-2-methyl-3-pyrrolecarboxylate was dissolved in pyridine 15-, and ethyl After stirring for 2 hours, the mixture was cooled to room temperature, the precipitated crystals were filtered, and recrystallized from chloroform to obtain 0.5 g of the desired product. Ta. Yield 31.8%, m
p 226-227.5°C Representative examples of the compounds of the present invention produced in the same manner as in the above examples are shown in Table 1.

Table 1 [Effects of the Invention] The compounds of the present invention can be used as raw materials for fluorescent compositions as shown below.

Table 2 [Note] Absorption maximum wavelength of absorption spectrum 22 Molar extinction coefficient 3) Maximum wavelength of fluorescence spectrum 4) Stokes shift: Difference between maximum wavelength of fluorescence spectrum and maximum wavelength of absorption spectrum 5) Fluorescence quantum yield: Sulfuric acid Measured using a 1.0N-Hz So/aqueous solution of quinine as a standard substance.

Claims (2)

[Claims] (1) General formula ▲ Numerical formula, chemical formula, table, etc. ▼ [In the formula, R^1 is a hydrogen atom or an acyl group, R^2 is an alkyl group, aryl group, or OR^5 (R^5 is a hydrogen atom , represents an alkyl group or an aryl group.) R^2' represents a hydrogen atom, an alkyl group or an aryl group, and R^4 represents a hydrogen atom, an alkyl group or an aryl group. ] A compound represented by (2) The compound represented by the general formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (In the formula, R^1, R^2, R^3 are the same as above.) The compound represented by the general formula R^4NCO is the same as above. indicate the same meaning. ) is a general formula characterized by ring-closing a compound represented by A method for producing a compound represented by