# US 4,393,216 A · Method of producing aminobenzimidazolones

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- Number: US 4,393,216 A
- Document ID: US4393216A
- Status: Granted
- Kind: A
- Application number: 06/275,619
- Filed: 1981-06-22
- Granted: 1983-07-12
- Earliest claimed: 1980-12-30
- Assignees: Showa Chemical Co., Ltd.; Osaka Municipal Government
- Inventors: Tsuneaki Hirashima; Toshiyuki Miyata; Yoshikazu Yamamoto; Mitsuyuki Kato
- Web page: https://patentgrep.com/patent/US4393216A

## CPC

- C07D 235/26: Oxygen atoms
- C07D: HETEROCYCLIC COMPOUNDS (macromolecular compounds C08)

## Abstract

A method of producing aminobenzimidazolones which comprises reacting a compound I having the general formula ##STR1## wherein X, Y and Z independently represent a substituent selected from the group consisting of a nitro group and an amino group, with carbon monoxide in solvent in the presence of selenium and an inorganic base or an organic base, and in the presence of water when the compound I has nitro groups, thereby providing a compound II having the general formula ##STR2##

## Claims

### Claim 1

A method of producing 5-aminobenzimidazolones which comprises reacting a 2,4-dinitroaniline with carbon monoxide in a solvent in the presence of selenium, a base selected from the group consisting of tertiary amines, N,N-dialkylamides and inorganic bases selected from the group consisting of hydroxides, oxides, carbonates, bicarbonates and sulfides or alkali metals and alkaline earth metals, and water, said 2,4-dinitroaniline containing no additional substituents or only containing substituents which are substantially inert in the reaction.

### Claim 2 (depends on 1)

The method as claimed in claim 1 wherein selenium is used in the amount of 0.1 to 10 moles per mole of compound I.

### Claim 3 (depends on 1)

The method as claimed in claim 1 wherein the pressure of carbon monoxide is 1 to 100 Kg/cm.sup.2.

### Claim 4 (depends on 1)

The method as claimed in claim 1 wherein the organic base is a tertiary amine.

### Claim 5 (depends on 4)

The method as claimed in claim 4 wherein the tertiary amine is a trialkylamine, pyridine, an alkylpyridine, an N-alkylpyrrolidone or an N-alkylpyrrolidine.

### Claim 6 (depends on 5)

The method as claimed in claim 5 wherein the trialkylamine is triethylamine.

### Claim 7 (depends on 1)

The method as claimed in claim 1 wherein the organic base is an N,N-dialkylamide.

### Claim 8 (depends on 7)

The method as claimed in claim 7 wherein the N,N-dialkylamide is N,N-dimethylformamide or N,N-dimethylacetamide.

### Claim 9 (depends on 1)

The method as claimed in claim 1 wherein the inorganic base is a hydroxide, oxide, carbonate, bicarbonate or sulfide of an alkali metal or an alkaline earth metal.

### Claim 10 (depends on 9)

The method as claimed in claim 9 wherein the alkali metal is potassium or sodium.

### Claim 11 (depends on 9)

The method as claimed in claim 9 wherein the hydroxide is potassium hydroxide or sodium hydroxide.

### Claim 12 (depends on 1)

The method as claimed in claim 1 wherein the reactant is 2,4-dinitroaniline and the product is 5-aminobenzimidazolone.

### Claim 13 (depends on 1)

the method as claimed in claim 1 wherein the reactant is 2,4-dinitro-6-chloroaniline and the product is 4-chloro-6-aminobenzimidazolone.