934-32-7

Basic information

• Product Name: 2-Aminobenzimidazole
• Synonyms: 2-Aminobenzimidazole;2-Benzimidazolamine;2-AMINOBENZIMIDAZOLE PESTANAL, 250 MG;2-AMINOBENZIMIDAZOLE, 250MG, NEAT;2-Aminobenzimidazole, 99+%;1H-Benzimidazol-2-amine(9CI);AMINO-2-BENZIMIDAZOLE;2-Aminobenzimidazole, 98+%;1H-Benzimidazol-2-amin
• CAS NO: 934-32-7
• Molecular Formula: C₇H₇N₃
• Molecular Weight: 133.15
• EINECS: 213-280-6
• Product Categories: BENZIMIDAZOLE;Imidazol&Benzimidazole
• Mol File: 934-32-7.mol
• Article Data: 72

Chemical Properties

• Melting Point: 226-230 °C(lit.)
• Boiling Point: 235.67°C (rough estimate)
• Flash Point: 204.6 °C
• Appearance: Yellow to beige or light brown/Crystalline Powder, Crystals or Flakes
• Density: 1.1873 (rough estimate)
• Vapor Pressure: 1.23E-05mmHg at 25°C
• Refractive Index: 1.5341 (estimate)
• Storage Temp.: Store below +30°C.
• Solubility: <1g/l slightly soluble
• PKA: 11.41±0.10(Predicted)
• Water Solubility: Soluble in water (Slightly).
• BRN: 116525
• CAS DataBase Reference: 2-Aminobenzimidazole(CAS DataBase Reference)
• NIST Chemistry Reference: 2-Aminobenzimidazole(934-32-7)
• EPA Substance Registry System: 2-Aminobenzimidazole(934-32-7)

Safety Data

• Hazard Codes: Xn
• Statements: 22-36/37/38-43
• Safety Statements: 26-36/37/39-22
• WGK Germany: 3
• RTECS: DD5775000
• TSCA: Yes
• Hazardous Substances Data: 934-32-7(Hazardous Substances Data)

Usage

Chemical Properties

light yellow to cream or beige powder or flakes

Uses

2-Aminobenzimidazole was used in the hydrolysis of a choline carbonate. It was also used in the synthesis of imidazo[1,2-a]benzimidazoles.

Preparation

Synthesis of 2-aminobenzimidazole: Cyanogen bromide (3.5 g., 0.034 mole) was added in small portions, with shaking, to a suspension of o-phenylenediamine (4.2 g. , 0.34 mole) in water (40 ml), the exothermic reaction mixture was cooled to room temperature and it was stirred for 36hrs. The solution was filtered after standing overnight. Sodium hydroxide (1.4 g., 0.034 mole) in 30 ml of water was then added and the solution was evaporated. The solid thus obtained was filtered and recrystalized from water. Yield 85%, m.p. 228 - 230°C

Definition

ChEBI: 2-aminobenzimidazole is a member of the class of benzimidazoles that is benzimidazole in which the hydrogen at position 2 is replaced by an amino group. It has a role as a marine xenobiotic metabolite.

General Description

Plates (in water); white powder.

Air & Water Reactions

Insoluble in water.

Reactivity Profile

2-Aminobenzimidazole neutralizes acids in exothermic reactions to form salts plus water. May be incompatible with isocyanates, halogenated organics, peroxides, phenols (acidic), epoxides, anhydrides, and acid halides. May generate hydrogen, a flammable gas, in combination with strong reducing agents such as hydrides.

Health Hazard

ACUTE/CHRONIC HAZARDS: When heated to decomposition 2-Aminobenzimidazole emits toxic fumes of nitrogen oxides.

Fire Hazard

Flash point data for 2-Aminobenzimidazole are not available; however, 2-Aminobenzimidazole is probably combustible.

Safety Profile

Poison by intravenous and intraperitoneal routes. Moderately toxic by ingestion. An experimental teratogen. Mutation data reported. When heated to decomposition it emits toxic NO,. See also AROUTIC AMINES.

InChI:InChI=1/C7H7N3/c8-7-9-5-3-1-2-4-6(5)10-7/h1-4H,(H3,8,9,10)

Synthetic route

2-azido-1H-benzo[d]imidazole (1516-74-1) → 1H-benzimidazol-2-amine (934-32-7)

Conditions	Yield
With sodium tetrahydroborate; tin bis(1,2-benzenethiolate) In tetrahydrofuran; phosphate buffer at 10℃; for 0.5h; pH=10; Reduction;	100%
With dibutyltin In benzene at 40℃; for 2h; other reagents;	98%
With acetic acid In dichloromethane at 20℃; for 2h; Irradiation;

bromocyane (506-68-3) + 1,2-diamino-benzene (95-54-5) → 1H-benzimidazol-2-amine (934-32-7)

Conditions	Yield
In methanol; water at 20 - 60℃; Inert atmosphere;	97%
In ethanol; water at 70℃; for 1h;	90%
In methanol; water at 50℃; for 1h;	89%

aminoiminomethanesulfonic acid (1184-90-3) + 1,2-diamino-benzene (95-54-5) → 1H-benzimidazol-2-amine (934-32-7)

Conditions	Yield
In isopropyl alcohol at 60℃;	95%

formamide (77287-34-4, 77287-35-5, 60100-09-6) + 1,2-diamino-benzene (95-54-5) → 1H-benzimidazol-2-amine (934-32-7)

Conditions	Yield
With N-sulfonated biguanidine modified silica coated on cobalt ferrite nanoparticle core In ethanol at 20℃; for 0.3h; Green chemistry;	92%

cyanogen bromide + 1,2-diamino-benzene (95-54-5) → 1H-benzimidazol-2-amine (934-32-7)

Conditions	Yield
In methanol; water at 20℃; for 24h;	88%
In water at 20℃;	75%

N-(1H-benzimidazol-2-yl)-N'-(p-methylbenzylidene)hydrazine → 1H-benzimidazol-2-amine (934-32-7) + para-methylbenzonitrile (104-85-8)

Conditions	Yield
at 700℃; under 0.02 Torr; Gas phase;	A 85% B 86%

N-(1H-benzimidazol-2-yl)-N'-(p-methoxybenzylidene)hydrazine → 1H-benzimidazol-2-amine (934-32-7) + 4-methoxybenzonitrile (874-90-8)

Conditions	Yield
at 700℃; under 0.02 Torr; Gas phase;	A 78% B 85%

bromocyane (506-68-3) + o-phenylenediamine dihydrochloride (615-28-1) → 1H-benzimidazol-2-amine (934-32-7)

Conditions	Yield
Stage #1: bromocyane; o-phenylenediamine dihydrochloride With sodium hydrogencarbonate In water; acetonitrile at 0 - 20℃; Stage #2: With sodium carbonate In water; acetonitrile	85%

lobendazole (6306-71-4) → 1H-benzimidazol-2-amine (934-32-7)

Conditions	Yield
In N,N-dimethyl-formamide for 4h; Heating;	82%

N-tert-butyl-1H-benzo[d]imidazol-2-amine (1438395-75-5) → 1H-benzimidazol-2-amine (934-32-7)

Conditions	Yield
With hydrogenchloride In water for 12h; Reflux;	82%

1H-benzimidazol-2-ylcarbamic acid methyl ester (162976-69-4) → 1H-benzimidazol-2-amine (934-32-7)

Conditions	Yield
With sodium hydroxide In water for 2h; Reflux;	80%
Stage #1: 1H-benzimidazol-2-ylcarbamic acid methyl ester With sodium hydroxide In water for 2h; Reflux; Stage #2: With hydrogenchloride In water	65%
With oxygen In various solvent(s) at 20℃; for 5h; pH=11; Quantum yield; Kinetics; Further Variations:; pH-values; Reagents; conc. of dissolved O2; Decomposition; Photolysis;
Alkaline conditions;
With water Alkaline conditions;

N-(1H-benzimidazol-2-yl)-N'-benzylidenehydrazine (60059-51-0) → 1H-benzimidazol-2-amine (934-32-7) + benzonitrile (100-47-0)

Conditions	Yield
at 700℃; under 0.02 Torr; Gas phase;	A 73% B 78%

guanidine nitrate (113-00-8) + 1,2-diamino-benzene (95-54-5) → 1H-benzimidazol-2-amine (934-32-7)

Conditions	Yield
Irradiation; microwave;	75%

N-(1H-benzimidazol-2-yl)-N'-(p-chlorobenzylidene)hydrazine → 4-Cyanochlorobenzene (623-03-0) + 1H-benzimidazol-2-amine (934-32-7)

Conditions	Yield
at 700℃; under 0.02 Torr; Gas phase;	A 65% B 67%

N-(1H-benzimidazol-2-yl)-N'-(p-nitrobenzylidene)hydrazine → 1H-benzimidazol-2-amine (934-32-7) + benzonitrile (100-47-0) + 4-nitrobenzonitrile (619-72-7)

Conditions	Yield
at 700℃; under 0.02 Torr; Gas phase;	A 65% B 10% C 58%

1,3-dicarbethoxy-S-methylisothiourea (34840-26-1) + 1,2-diamino-benzene (95-54-5) → 1H-benzimidazol-2-amine (934-32-7) + 1H-benzimidazol-2-ol (615-16-7)

Conditions	Yield
In N,N-dimethyl-formamide for 5h; Heating;	A 60% B 22%

1,2-diamino-benzene (95-54-5) + di(1H-imidazol-1-yl)methanimine (104619-51-4) → 1H-benzimidazol-2-amine (934-32-7)

Conditions	Yield
In tetrahydrofuran for 12h; Heating;	59%

N-cyano-N-phenyl-p-toluenesulfonamide (55305-43-6) + 1,2-diamino-benzene (95-54-5) → 1H-benzimidazol-2-amine (934-32-7)

Conditions	Yield
With lithium hexamethyldisilazane In tetrahydrofuran; hexane at 5 - 20℃; for 1h; Green chemistry;	56%

2-Amino-1-benzylideneaminobenzimidazole (122128-68-1) → 1H-benzimidazol-2-amine (934-32-7) + benzonitrile (100-47-0)

Conditions	Yield
In nitrobenzene for 12h; Heating;	A 47% B n/a

N-(1H-benzimidazol-2-yl)-N'-benzylidenehydrazine (60059-51-0) → 1H-benzimidazol-2-amine (934-32-7) + 1,3-diphenyl-8H-2,3a,8-triazacyclopenta[a]indene + 5,11-diphenyl-6H,12H-dibenzimidazo[1,2-a;1',2'-d]pyrazine (1233945-59-9) + lophine (484-47-9) + benzonitrile (100-47-0)

Conditions	Yield
at 280℃; under 0.045 Torr; for 0.25h; Gas phase;	A 20% B 15% C 18% D 21% E 15%

1H-benzimidazole-2-sulfonic acid (40828-54-4) → 1H-benzimidazol-2-amine (934-32-7)

Conditions	Yield
With ammonium hydroxide at 145 - 150℃; for 5h;
With ammonium hydroxide
With ammonia

Ammonium salt of Benzimidazole-2-sulfonic Acid → 1H-benzimidazol-2-amine (934-32-7) + 2,3-dihydrobenzimidazol-2-thione (583-39-1)

Conditions	Yield
With formamide Heating; Yield given. Yields of byproduct given;
With formamide Heating; Yield given. Yields of byproduct given;
With formamide Product distribution; Heating; also 1-alkyl-substituted benzimidazole-2-sulfonic acids investigated;

sodium cyanide (143-33-9) + 1,2-diamino-benzene (95-54-5) → 1H-benzimidazol-2-amine (934-32-7)

Conditions	Yield
With bromine 1) water, 5 deg C; 2) water, room temperature, 5 h.; Yield given. Multistep reaction;

2-(1-ethylbenzimidazol-2-yl)methyleneaminobenzimidazole (245111-10-8) → 1H-benzimidazol-2-amine (934-32-7) + 1-ethyl-1H-benzo[d]imidazole-2-carbaldehyde (34734-20-8)

Conditions	Yield
With water Hydrolysis;

2-(1-vinylbenzimidazol-2-yl)methyleneaminobenzimidazole → 1H-benzimidazol-2-amine (934-32-7) + 1-vinylbenzimidazole-2-carboxaldehyde (118482-08-9)

Conditions	Yield
With water In dimethylsulfoxide-d6 for 120h; Hydrolysis;

-urea → 1H-benzimidazol-2-amine (934-32-7)

Conditions	Yield
With hydrogenchloride

N.N'-o-phenylene-N''-benzoyl-guanidine → 1H-benzimidazol-2-amine (934-32-7)

Conditions	Yield
With potassium hydroxide

N.N'-o-phenylene-N''-cinnamoyl-guanidine → 1H-benzimidazol-2-amine (934-32-7)

Conditions	Yield
With potassium hydroxide

N.N'-o-phenylene-N.N''-dicyano-guanidine → 1H-benzimidazol-2-amine (934-32-7)

Conditions	Yield
With hydrogenchloride

1H-benzimidazol-2-amine (934-32-7) + cyclohexanone-2-carboxamide (22945-27-3) → 1,2,3,4,6,12-Hexahydrobenzimidazo<2,1-b>chinazolin-12-on (83785-99-3)

Conditions	Yield
With toluene-4-sulfonic acid In toluene for 3h; Heating;	100%

1H-benzimidazol-2-amine (934-32-7) + (4S,4'S)-4-(benzyl(methyl)amino)-4-(2',2'-dimethyl-1,3-dioxolan-4'-yl)-3-methoxybut-2-enal → (1R,4'S)-{benzo[4,5]imidazo[1,2-a]pyrimidin-4-yl-(2',2'dimethyl-1',3-dioxolan-4'-yl)-methyl}benzylmethylamine

Conditions	Yield
In ethanol Reflux; Inert atmosphere;	100%

1H-benzimidazol-2-amine (934-32-7) + acetyl chloride (75-36-5) → 2-acetamidobenzimidazole (21202-05-1)

Conditions	Yield
Heating;	99%
With triethylamine for 16h; Cooling with ice;	72%
With triethylamine at 50 - 55℃;

3-(2-furyl)-2-(2-methoxycarbonylphenylhydrazono)-3-oxo-propanal (289499-65-6) + 1H-benzimidazol-2-amine (934-32-7) → methyl 2-(2-{1-[(1H-benzimidazol-2-ylimino)-methyl]-2-(furan-2-yl)-2-oxo-ethylidene}hydrazino)benzoate

Conditions	Yield
In ethanol for 0.166667h; microwave irradiation;	99%

2-(2-methoxycarbonylphenylhydrazono)-3-oxo-3-(2-pyrrolyl)propanal (289499-66-7) + 1H-benzimidazol-2-amine (934-32-7) → methyl 2-(2-{1-[(1H-benzimidazol-2-ylimino)-methyl]-2-oxo-2-(1H-pyrrol-2-yl)-ethylidene}hydrazino)benzoate

Conditions	Yield
In ethanol for 0.166667h; microwave irradiation;	99%

1H-benzimidazol-2-amine (934-32-7) + 2-Hydroxy-1,4-naphthoquinone (83-72-7) + 4-nitrobenzaldehdye (555-16-8) → 2-(((1H-benzo[d]imidazol-2-yl)amino)(4-nitrophenyl)methyl)-3-hydroxynaphthalene-1,4-dione (1259091-97-8)

Conditions	Yield
With MCM-41 In ethanol at 20℃; for 1.16667h; Green chemistry;	99%
With montmorillonite K-10 In ethanol at 20℃; for 8h;	93%
With indium(III) chloride In water for 6h; Reflux;	80%

1H-benzimidazol-2-amine (934-32-7) + pyrimidine-2,4,5,6(1H,3H)-tetraone (61066-33-9, 61066-34-0, 61066-35-1, 61127-23-9) + 2,5-dihydroxy-1,4-benzoquinone (615-94-1) → 2-amino-1H-benzo[d]imidazol-3-ium 3-hydroxy-1-(5-hydroxy-2,4,6-trioxohexahydropyrimidin-5-yl)-2,5,6-trioxocyclohex-3-en-1-ide (1367748-62-6)

Conditions	Yield
In chloroform for 4h; Reflux;	99%

1H-benzimidazol-2-amine (934-32-7) + 4-fluorobenzaldehyde (459-57-4) + cyanoacetic acid amide (107-91-5) → 2,5-bis(4-fluorophenyl)-2,3,5,12-tetrahydrobenzo[4,5]imidazo[1,2-a]pyrimido[4,5-d]pyrimidin-4(1H)-one (1392308-35-8)

Conditions	Yield
With silica sulfuric acid In ethylene glycol at 120℃; for 0.0166667h; Catalytic behavior; Reagent/catalyst; Solvent; Green chemistry;	99%
With poly(ethylene glycol)-400 at 20℃; for 1h; Green chemistry;	90%
In water for 2h; Reflux;	89%

1H-benzimidazol-2-amine (934-32-7) + dimedone (126-81-8) + ortho-bromobenzaldehyde (6630-33-7) → 3,3-dimethyl-12-(2-bromophenyl)-1,2,3,4,5,12-hexahydrobenzo[4,5]imidazo[2,1-b]quinazolin-1-one

Conditions	Yield
With acetic acid at 60℃; for 0.333333h; Green chemistry;	99%

1H-benzimidazol-2-amine (934-32-7) + 3-methoxy-benzaldehyde (591-31-1) + cyanoacetic acid amide (107-91-5) → 2,5-bis(3-methoxyphenyl)-2,3,5,12-tetrahydrobenzo[4,5]imidazo[1,2-a]pyrimido[4,5-d]pyrimidin-4(1H)-one

Conditions	Yield
With silica sulfuric acid In ethylene glycol at 120℃; for 0.0166667h; Green chemistry;	99%

1H-benzimidazol-2-amine (934-32-7) + 2,3,5-trichloro-6-methoxybenzoic acid chloride (69954-01-4) → 1-(3,5,6-trichloro-2-methoxybenzoyl)-2-aminobenzimidazole

Conditions	Yield
With triethylamine In acetone at 55℃;	98.7%
	98%

1H-benzimidazol-2-amine (934-32-7) + 3-nitro-benzaldehyde (99-61-6) → (1H-benzimidazol-2-yl)-(3-nitro-benzyliden)-amine (124066-54-2)

Conditions	Yield
In toluene for 20h; Heating;	98%

1H-benzimidazol-2-amine (934-32-7) + 4-nitrobenzaldehdye (555-16-8) + dimedone (126-81-8) → 3,3-dimethyl-12-(4-nitrophenyl)-3,4,5,12-tetrahydrobenzo[4,5]imidazo-[2,1-b]quinazolin-1(2H)-one

Conditions	Yield
With silica In acetonitrile at 25 - 30℃; for 0.5h; Green chemistry;	98%
With toluene-4-sulfonic acid In acetonitrile at 40 - 50℃; for 0.333333h; Green chemistry;	98%
With starch functionalized Fe3O4 nanoparticles In water at 20℃; for 0.116667h; Irradiation; Green chemistry; chemoselective reaction;	98%

1H-benzimidazol-2-amine (934-32-7) + 4-methoxy-benzaldehyde (123-11-5) + dimedone (126-81-8) → 3,3-dimethyl-12-(4-methoxyphenyl)-3,4,5,12-tetrahydrobenzo [4,5]imidazo-[2,1-b]quinazolin-1(2H)-one

Conditions	Yield
With starch functionalized Fe3O4 nanoparticles In water at 20℃; for 0.15h; Irradiation; Green chemistry; chemoselective reaction;	98%
With acetic acid at 60℃; for 0.333333h; Green chemistry;	96%
With 4-methyl-4-sulfonic acid morpholinium chloride at 90℃; for 0.0833333h; Reagent/catalyst;	96%

1H-benzimidazol-2-amine (934-32-7) + formaldehyd (50-00-0) + (4-fluoro-phenyl)-thiourea (459-05-2) → 5-(1H-benzoimidazol-2-yl)-1-(4-fluoro-phenyl)-[1,3,5]triazinane-2-thione

Conditions	Yield
In water for 0.025h; microwave irradiation;	98%

1H-benzimidazol-2-amine (934-32-7) + 4-chlorobenzaldehyde (104-88-1) + dimedone (126-81-8) → 12-(4-chlorophenyl)-3,3-dimethyl-3,4,5,12-tetrahydrobenzo[4,5]imidazo[2,1-b]quinazoline-1(2H)-one

Conditions	Yield
With butane-1-sulfonic acid modified starch coated γ-Fe2O3 magnetic nanoparticles In neat (no solvent) at 100℃; for 0.166667h; Catalytic behavior; Reagent/catalyst; Solvent; Temperature;	98%
With starch functionalized Fe3O4 nanoparticles In water at 20℃; for 0.116667h; Irradiation; Green chemistry; chemoselective reaction;	98%
With 4-methyl-4-sulfonic acid morpholinium chloride at 90℃; for 0.0666667h; Catalytic behavior; Reagent/catalyst; Temperature;	97%

3-(4-chlorophenyl)-2-(2-methoxycarbonylphenylhydrazono)-3-oxo-propanal (824953-65-3) + 1H-benzimidazol-2-amine (934-32-7) → methyl 2-(2-{1-[(1H-benzimidazol-2-ylimino)-methyl]-2-(4-chlorophenyl)-2-oxo-ethylidene}hydrazino)benzoate

Conditions	Yield
In ethanol for 0.166667h; microwave irradiation;	98%

1H-benzimidazol-2-amine (934-32-7) + 2-[hydroxy-(3-nitro-phenyl)-methyl]-acrylic acid methyl ester (360574-95-4) → 6-[(3-nitrophenyl)hydroxymethyl]-5,6-dihydro-8H-benzo[4,5]imidazo[1,2-a]pyrimidin-7-one (1227670-24-7)

Conditions	Yield
In 1,4-dioxane at 100℃; for 2h;	98%
In tetrahydrofuran; water at 50℃; for 24h; Michael addition-cyclization tandem reaction;	77%

pyridine-4-carbaldehyde (872-85-5) + 1H-benzimidazol-2-amine (934-32-7) + ethyl acetoacetate (141-97-9) → ethyl 2-methyl-4-(pyridin-4-yl)-1,4-dihydrobenzo[4,5]imidazo[1,2-a]pyrimidine-3-carboxylate (727405-62-1)

Conditions	Yield
With Thiamine hydrochloride In water for 3h; Reflux;	98%
With zinc perchlorate In methanol for 6h; Reflux;	70%

1H-benzimidazol-2-amine (934-32-7) + ethyl acetoacetate (141-97-9) + 3-Chlorobenzaldehyde (587-04-2) → 4-(3-chlorophenyl)-2-methyl-1,4-dihydrobenzo[4,5]imidazo[1,2-a]pyrimidine-3-carboxylic acid ethyl ester (727405-73-4)

Conditions	Yield
With poly(vinylpyrrolidonium) perchlorate ([PVPH]ClO4) at 100℃; for 0.333333h;	98%
With N,N,N’,N’-tetrabromobenzene-1,3-disulfonamide In neat (no solvent) at 100℃; for 0.666667h; Reagent/catalyst; Green chemistry;	96%
With 4,4'-(butane-1,4-diyl)bis(1-sulfo-1,4-diazabicyclo[2.2.2]octane-1,4-diium) tetrachloride In neat (no solvent) at 90℃; for 0.25h; Green chemistry;	92%

1H-benzimidazol-2-amine (934-32-7) + 2,5-bis(chloromethyl)-1,3,4-oxadiazole (541540-90-3) → C18H16N8O (1489236-38-5)

Conditions	Yield
With potassium hydroxide In acetone Reflux;	98%

1H-benzimidazol-2-amine (934-32-7) + 4-ethoxy-1,1,1-trichloro-3-buten-2-one (83124-74-7) → 2-(trichloromethyl)benzo[4,5]imidazol[1,2-a]pyrimidine (1320212-46-1)

Conditions	Yield
With triethylamine In toluene for 2h; Reflux;	98%

1H-benzimidazol-2-amine (934-32-7) + 4-chlorobenzaldehyde (104-88-1) + malononitrile (109-77-3) → 2-amino-4-(4-chlorophenyl)-1,4-dihydrobenzo[4,5]imidazolo[1,2-a]pyrimidine-3-carbonitrile (378760-56-6)

Conditions	Yield
With Ag-TiO2 nanocomposite In neat (no solvent) at 60℃; for 0.133333h; Catalytic behavior; Solvent; Temperature;	98%
With starch functionalized Fe3O4 nanoparticles In water at 20℃; for 0.05h; Irradiation; Green chemistry; chemoselective reaction;	97%
With poly(vinylpyrrolidonium) perchlorate ([PVPH]ClO4) at 100℃; for 0.25h;	96%

1H-benzimidazol-2-amine (934-32-7) + 4-fluorobenzaldehyde (459-57-4) + malononitrile (109-77-3) → 2-amino-4-(4-fluorophenyl)-1,4-dihydrobenzo[4,5]imidazolo[1,2-a]pyrimidine-3-carbonitrile (380891-82-7)

Conditions	Yield
With starch functionalized Fe3O4 nanoparticles In water at 20℃; for 0.05h; Irradiation; Green chemistry;	98%
With Ag-TiO2 nanocomposite In neat (no solvent) at 60℃; for 0.133333h;	97%
With zinc ferrite In methanol at 70℃; for 1.48333h; Sonication; Green chemistry;	92%

1H-benzimidazol-2-amine (934-32-7) + m-bromobenzoic aldehyde (3132-99-8) + malononitrile (109-77-3) → 2-amino-4-(3-bromophenyl)-1,4-dihydrobenzo[4,5]imidazolo[1,2-a]pyrimidine-3-carbonitrile (933194-36-6)

Conditions	Yield
With poly(vinylpyrrolidonium) perchlorate ([PVPH]ClO4) at 100℃; for 0.0666667h;	98%
With 1-methyl-3-(trimethoxysilylpropyl)imidazolium hydrogen sulfate supported on rice husk ash In neat (no solvent) at 100℃; for 0.05h; Green chemistry;	90%
With zinc ferrite In methanol at 70℃; for 1.36667h; Sonication; Green chemistry;	90%

1H-benzimidazol-2-amine (934-32-7) + (4-isopropylbenzaldehyde) (122-03-2) + malononitrile (109-77-3) → 2-amino-4-(4-isopropylphenyl)-1,4-dihydrobenzo[4,5]imidazolo[1,2-a]pyrimidine-3-carbonitrile (932995-93-2)

Conditions	Yield
With poly(vinylpyrrolidonium) perchlorate ([PVPH]ClO4) at 100℃; for 0.0666667h;	98%
With toluene-4-sulfonic acid In neat (no solvent) at 80℃; for 0.55h; Green chemistry;	92%
With 1-methyl-3-(trimethoxysilylpropyl)imidazolium hydrogen sulfate supported on rice husk ash In neat (no solvent) at 100℃; for 0.0833333h; Green chemistry;	88%

1H-benzimidazol-2-amine (934-32-7) + 4-bromo-benzaldehyde (1122-91-4) + malononitrile (109-77-3) → 2-amino-4-(4-bromophenyl)-1,4-dihydrobenzo[4,5]imidazolo[1,2-a]pyrimidine-3-carbonitrile (1608468-74-1)

Conditions	Yield
With Ag-TiO2 nanocomposite In neat (no solvent) at 60℃; for 0.166667h;	98%
With starch functionalized Fe3O4 nanoparticles In water at 20℃; for 0.0666667h; Irradiation; Green chemistry;	97%
With poly(vinylpyrrolidonium) perchlorate ([PVPH]ClO4) at 100℃; for 0.333333h;	95%

1H-benzimidazol-2-amine (934-32-7) + m-bromobenzoic aldehyde (3132-99-8) + ethyl acetoacetate (141-97-9) → ethyl 4-(3-bromophenyl)-1,4-dihydro-2-methylpyrimido[1,2-a]benzimidazole-3-carboxylate (932210-11-2)

Conditions	Yield
With poly(vinylpyrrolidonium) perchlorate ([PVPH]ClO4) at 100℃; for 0.666667h;	98%
With Copper-polysulfonamide complex immobilized on graphene oxide In ethanol for 0.333333h; Reflux;	95%
With N,N,N’,N’-tetrabromobenzene-1,3-disulfonamide In neat (no solvent) at 100℃; for 0.583333h; Reagent/catalyst; Green chemistry;	90%

1H-benzimidazol-2-amine (934-32-7) + 3-[3-(2-oxiranyl-ethoxy)-6-oxo-6H-pyridazin-1-ylmethyl]-benzoic acid methyl ester (1622068-87-4) → potassium 3-{3-[4-(2-amino-benzoimidazol-1-yl)-3-hydroxy-butoxy]-6-oxo-6H-pyridazin-1-ylmethyl}-benzoate (1622069-40-2)

Conditions	Yield
With potassium hydroxide In methanol; water at 100℃; for 1h; Microwave irradiation;	98%

Upstream product

• 506-68-3 bromocyane 
• 95-54-5 1,2-diamino-benzene 
• 6306-71-4 lobendazole 
• 34840-26-1 1,3-dicarbethoxy-S-methylisothiourea 
• 21729-98-6 methyl-N-cyano carbamate 
• 144528-04-1 N-benzylidene-1H-benzo[d]imidazol-2-amine 
• 1184-90-3 aminoiminomethanesulfonic acid 
• 615-28-1 o-phenylenediamine dihydrochloride 
• 104619-51-4 di(1H-imidazol-1-yl)methanimine 
• 245111-10-8 2-(1-ethylbenzimidazol-2-yl)methyleneaminobenzimidazole 
• 122128-68-1 2-Amino-1-benzylideneaminobenzimidazole 
• 1516-74-1 2-azido-1H-benzo[d]imidazole 
• 40828-54-4 1H-benzimidazole-2-sulfonic acid 
• 77287-34-4 formamide 

Downstream Products

• 113059-59-9 N-(3-oxo-3-phenyl-propionyl)-sulfanilic acid-(1H-benzimidazol-2-ylamide) 
• 25513-97-7 2-Methylpyrimido<1,2-a>benzimidazol 
• 490-59-5 alloxazine 
• 50290-45-4 2-phenyl-1H-benz[4,5]imidazo[1,2-a]pyrimidin-4-one 
• 101281-34-9 N-(4-ethoxy-phenyl)-N'-(1H-benzimidazol-2-yl)-formamidine 
• 52938-06-4 1-Ethoxycarbonyl-2-amino-benzimidazol 
• 50290-51-2 2-methylpyrimido[1,2-a]benzimidazol-4(1H)-one 
• 100621-08-7 N-(1H-benzimidazol-2-yl)-N'-phenyl-formamidine 
• 107553-43-5 2,4-diphenylbenzimidazo<1,2-a>pyrimidine 
• 100728-21-0 2-(1H-benzimidazol-2-ylamino)-hydroquinone 
• 102555-25-9 2,5-bis-(1H-benzimidazol-2-ylamino)-[1,4]benzoquinone 
• 84587-80-4 N-(1H-benzo[d]imidazol-2-yl)-2-chloroacetamide 
• 109722-53-4 3-phenyl-1H-benz[4,5]imidazo[1,2-a]pyrimidine-2,4-dione 
• 24370-25-0 1-(1H-benzo[d]-imidazol-2-yl)urea 

Relevant articles and documents

2-Amino- and 2-hydroxymethylbenzimidazolium bromides as protein tyrosine phosphatase 1В (PTP1В) inhibitors and other targets associated with diabetes mellitus

New 2-amino- and 2-hydroxymethylbenzimidazoles were synthesized and used to prepare the previously unknown 1,2,3-tri- and 1,2,3,5-tetrasubstituted benzimidazolium bromides with a biphenyl-containing substituent at the imidazole nitrogen atom. In some cases, these bromides exhibit activity against targets associated with diabetes mellitus. These compounds are strong protein tyrosine phosphatase 1B (PTP1B) inhibitors, exhibit chelating and antiglycation activity, but have no significant AT1 receptor antagonist activity. Hence, biphenyl-containing benzimidazolium derivatives can be considered as a basis for the development of new promising agents for the treatment of type 2 diabetes mellitus (DM2) and other diseases mediated by high phosphatase PTP1B activity.

Alternative and efficient method for the preparation of 2-acetamidobenzimidazoles

An alternative method for the synthesis of acetamidobenzimidazoles (3-6) has been developed, including the reacylation of methylbenzimidazol-2-ylcarbamate (carbendazim, MBC, 1) under the action of aliphatic and aromatic carboxylic acids. It was shown that with an increase in the size of the alkyl group and the reaction temperature (in the case of butyric acid), due to the decomposition of the resulting product, the yield of the target acyl products sharply decreases. The obtained compounds are homologues of the anthelmintic drug - N-(1H-benzimidazol-2-yl) acetamide (2-acetylaminobenzimidazole, 3). A possible mechanism of reacylation is presented.

Copper-promoted one-pot approach: Synthesis of benzimidazoles

A facile, one-pot, and proficient method was developed for the production of various 2-arylaminobenzimidazoles. This methodology is based for the first time on a copper catalyst promoted domino C-N cross-coupling reaction for the generation of 2-arylaminobenzimidazoles. Mechanistic investigations revealed that the synthetic pathway involves a copper-based desulphurization/nucleophilic substitution and a subsequent domino intra and intermolecular C-N cross-coupling reactions. Some of the issues typically encountered during the synthesis of 2-arylaminobezimidazoles, including the use of expensive catalytic systems and the low reactivity of bromo precursors, were addressed using this newly developed copper-catalyzed method. The reaction procedure is simple, generally with excellent substrate tolerance, and provides good to high yields of the desired products.