JPH06145142A - Production of 4-arylpyrrolones - Google Patents

Abstract

(57) [Summary] [Structure] General formula [Formula 1] [In the formula, Ar represents an optionally substituted aryl group or aromatic heterocyclic group, and R ¹ represents a lower alkyl group. And a compound represented by the general formula: R ² NH ₂ [wherein R ² represents an alkyl group, a cycloalkyl group, an aralkyl group, or an aryl group or an aromatic group which may be substituted, respectively] Represents a heterocyclic group. ] The reaction with an amine compound represented by the following formula in a non-polar solvent: [In the formula, Ar and R ² have the same meanings as described above. ]
The manufacturing method of 4-arylpyrrolones shown by these. According to the production method of the present invention, 4-arylpyrrolone represented by the general formula 3 can be easily produced.

Description

Detailed Description of the Invention

[0001]

OBJECT OF THE INVENTION The present invention relates to a process for preparing 4-arylpyrrolones.

DETAILED DESCRIPTION OF THE INVENTION As a result of intensive studies by the present inventor,
It was found that 4-arylpyrrolones can be easily produced by reacting aryl-4-bromo-2-butenoates with an amine compound in a nonpolar solvent, and completed the present invention. That is, the present invention has the general formula

[Chemical 4] [In the formula, Ar represents an optionally substituted aryl group or aromatic heterocyclic group, and R ¹ represents a lower alkyl group. ] And the compound represented by the general formula:

Embedded image R ² NH ₂ wherein, R ² each represents an alkyl group, a cycloalkyl group, or an aralkyl group, or each optionally substituted aryl group or an aromatic heterocyclic group. ] It reacts with the amine compound shown by these in a nonpolar solvent, General formula 6

[Chemical 6] [In the formula, Ar and R ² have the same meanings as described above. ]
The method for producing 4-arylpyrrolones represented by (hereinafter, referred to as the method of the present invention) is provided.

In the method of the present invention, the general formulas
Alternatively, the substituents of the compound represented by Chemical formula 6 will be described. Examples of the substituent in the optionally substituted aryl group or aromatic heterocyclic group represented by Ar or R ² include a halogen atom such as a fluorine atom, a chlorine atom and a bromine atom, a methyl group, an ethyl group, Examples include lower alkyl groups such as isopropyl group, lower alkoxy groups such as methoxy group and ethoxy group, nitro group, cyano group, and the like. Examples of aryl groups include phenyl group, 1-naphthyl group, and 2-naphthyl group. Examples of the aromatic heterocyclic group include 5-membered aromatic heterocyclic group such as thienyl group, furyl group and pyrazolyl group, and 6-membered aromatic heterocyclic group such as pyridyl group. Examples of the lower alkyl group represented by R ¹ include a methyl group, an ethyl group, a propyl group,
A butyl group can be mentioned. Examples of the alkyl group represented by R ² include methyl group, ethyl group, propyl group, isopropyl group, butyl group, tert-butyl group, isobutyl group, sec-
Examples thereof include C ₁ -C ₁₀ alkyl groups such as a butyl group. R ²
Examples of the cycloalkyl group represented by include C ₃ -C ₈ cycloalkyl groups such as cyclohexyl group and cyclopentyl group. The aralkyl group represented by R ² includes
Examples thereof include a benzyl group, a β-phenethyl group, an α-phenethyl group, and an α, α-dimethylbenzyl group.

Examples of the non-polar solvent used in the method of the present invention include aromatic hydrocarbons such as benzene and toluene, and aliphatic hydrocarbons such as hexane and heptane. The amount of the reagent used is usually 1.5 to 10 with respect to 1 equivalent of the compound represented by the general formula 4 from the reaction yield and the economical viewpoint.
It is 5 equivalents, preferably 1.5 to 2.5 equivalents. The reaction temperature range and the reaction time range are usually room temperature to 150 ° C. and 10 to 100 hours.
It is preferable to react for 10 to 100 hours. After completion of the reaction, the reaction solution is washed with a dilute acid such as dilute hydrochloric acid to remove excess amine compound, and then subjected to usual post-treatments such as washing with a dilute alkali, washing with water, drying, and concentration, and then the desired general formula 6 4-arylpyrrolones can be obtained. If necessary, it can be further purified by chromatography or recrystallization.

The compound represented by the general formula 4 used in the method of the present invention is, for example, the Witting-Horner reaction (WS Wadsworth, Jr., Organic Reactions, 25, 73-253).
(1977); AA Macco, RJde Brouwer, and HMBuck, J.Or
g.Chem., 42, 3196-3199 (1977)), the 3-aryl-2-butenoates are brominated with N-bromosuccinimide (NBS) (ACMoore, J. Am. Chem. Soc., 71,2583-2584 (194
9)) can be obtained.

[Chemical 7] [In the formula, Ar and R ¹ have the same meanings as described above. A compound represented by the general formula:
Arylpyrrolones are useful as intermediates for the production of natural physiologically active substances such as medicines and agricultural chemicals and bile pigments. (AHJackso
n, "Comprehensive Organic Chemistry," ed.by DHRBa
rton and DWOllis, Pergamon, Oxford, 1979, Vol.4, p 27
5-320; DJ Chadwick, "Comprehensive Heterocyclic Che
mistry, "ed.by ARKatritzky and CWRees, Pergamon,
Oxford, 1984, p 155-376.)

[0005]

【Example】

Example 1 Ethyl 4-bromo-3-phenyl-2-butenoate
1.82 g (20 mmol) of aniline was added to a solution prepared by dissolving 2.69 g (10 mmol) in 15 ml of benzene with stirring, and the mixture was stirred at room temperature for 2 hours. Add 35 ml of benzene and add 2
The mixture was heated under reflux for 9 hours. The reaction solution was cooled, washed successively with 5% hydrochloric acid water, 2% aqueous sodium hydroxide solution and water, and then the benzene layer was dried over anhydrous sodium sulfate. The residue obtained by distilling off the solvent was subjected to silica gel chromatography (elution solvent: dichloromethane / ethyl acetate = 4 /
1 (v / v), and the obtained residue was recrystallized from ethanol to give 1.76 g of N, 4-diphenylpyrrolone.
(Yield 75%) was obtained. Ar or / in Example 1
Example 1 except that R ² and R ² were changed to corresponding ones
An example manufactured in the same manner as in Table 1 is shown in Table 1.

[Table 1]

[0006]

INDUSTRIAL APPLICABILITY The 4-arylpyrrolones represented by the general formula 6 can be easily produced by the method of the present invention.

Claims (1)

[Claims] 1. A general formula: ## STR1 ## [In the formula, Ar represents an optionally substituted aryl group or aromatic heterocyclic group, and R ¹ represents a lower alkyl group. And a compound represented by the general formula: R ² NH ₂ [wherein R ² represents an alkyl group, a cycloalkyl group, an aralkyl group, or an aryl group or an aromatic group which may be substituted, respectively] Represents a heterocyclic group. ] The reaction with an amine compound represented by the following formula in a non-polar solvent: [In the formula, Ar and R ² have the same meanings as described above. ]
The manufacturing method of 4-arylpyrrolones shown by these.