ChemicalBook CAS DataBase List 5-BROMO-2-METHYL-1H-BENZIMIDAZOLE

5-BROMO-2-METHYL-1H-BENZIMIDAZOLE synthesis

11synthesis methods

Product Name:5-BROMO-2-METHYL-1H-BENZIMIDAZOLE
CAS Number:1964-77-8
Molecular formula:C8H7BrN2
Molecular Weight:211.06

1445-45-0 Synthesis

1445-45-0
341 suppliers
$10.00/5mL

875-51-4 Synthesis

875-51-4
302 suppliers
$5.00/1g

1964-77-8
127 suppliers
$6.00/250mg

Yield: 90%

Reaction Conditions:

with indium;acetic acid in ethyl acetate for 4 h;Reflux;Inert atmosphere;

Steps:

4.2. General procedure for the indium-mediated reductive reaction of 2-nitroanilines or 1,2-dinitroarenes with trimethyl orthoesters to benzimidazoles
General procedure: 2-Nitroaniline derivative (1 mmol) was added to a mixture of indium powder (574 mg, 5.0 mmol for 2-nitroaniline, 918 mg 8.0 mmol for 1,2-dinitroarene), and acetic acid (0.572 mL, 10 mmol) in ethyl acetate (2 mL), followed by the addition of trimethyl orthoester (2.0 mmol) in ethyl acetate (3 mL for 2-nitroaniline; 8 mL for 1,2-dinitroarene). The reaction mixture was stirred at reflux under a nitrogen atmosphere. After the reaction was completed, the reaction mixture was diluted with ethyl acetate (30 mL), filtered through Celite, poured into 10% NaHCO₃ (30 mL), and then extracted with ethyl acetate (30 mL×3). The combined organic extracts were dried over MgSO₄, filtered, and concentrated. The residue was eluted with ethyl acetate/hexane (v/v=10/90) for 2-phenylbenzimidazole derivatives or methanol/dichloromethane (v/v=1/99) for 2-methylbenzimidazole derivatives through a silica gel column to give the corresponding benzimidazoles. The structures of the benzimidazoles were characterized by ¹H NMR, ¹³C NMR, FTIR, and GC-MS, and were mostly known compounds. HRMS data were reported in addition for unknown compounds.

References:

Kim, Jaeho;Kim, Jihye;Lee, Hyunseung;Lee, Byung Min;Kim, Byeong Hyo [Tetrahedron,2011,vol. 67,# 41,p. 8027 - 8033] Location in patent:experimental part

78-39-7 Synthesis