ChemicalBook CAS DataBase List 4-Bromo-2-nitroaniline

4-Bromo-2-nitroaniline synthesis

11synthesis methods

Product Name:4-Bromo-2-nitroaniline
CAS Number:875-51-4
Molecular formula:C6H5BrN2O2
Molecular Weight:217.02

75-09-2 Synthesis

75-09-2
1208 suppliers
$10.00/25 mL

7529-22-8 Synthesis

7529-22-8
379 suppliers
$5.00/1g

15788-16-6
266 suppliers
$5.00/250mg

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

58442-17-4
95 suppliers
$42.00/100mg

Yield:875-51-4 452 mg (32%, 2 steps)

Reaction Conditions:

with LiAlH₄;tetrapropylammonium perruthennate;silica gel in tetrahydrofuran;N,N-dimethyl-formamide

Steps:

5 5-Formylbenzimidazole (18)
EXAMPLE 5 5-Formylbenzimidazole (18) A suspension of 5-benzimidazolecarboxylic acid (1.57 g, 9.7 mmol) in dry THF (50 ml) was cooled to -78° C. under N₂, and treated with LiAlH₄ (736 mg, 19.4 mmol). After the addition, the mixture was allowed to warm slowly to room temperature and then stirred at r.t. overnight. The mixture was quenched by MeOH and H₂ O cautiously, and passed through a short silica gel column eluding with 10% MeOH/EtOAc. The elude was concentrated to give 876 mg crude alcohol as a solid. The crude alcohol (876 mg) was dissolved in a mixture of DMF (3 ml), THF (10 ml) and CH₂ Cl₂ (40 ml). 4-Methylmorpholine N-oxide (2.25 g, 19.2 mmol), 4A molecular sieves (5 g), and TPAP (169 mg, 0.48 mmol) were subsequently added to the crude alcohol solution. The mixture was stirred at room temperature overnight, and filtered through a pad of silica gel eluding with 10% MeOH/EtOAc. The elute was concentrated and further purified by flash chromatography on silica gel eluding with 0-10% MeOH/EtOAc to give 452 mg (32%, 2 steps) of 17 as a white solid: mp 164°-166° C.; IR KBr) 3087, 2818, 1690, 1292; ¹ H NMR (CD₃ OD) δ 9.95 (1H, s), 8.34 (1H, s), 8.08 (1H, d, J=1.5), 7.74 (1H, dd, J=8.4, 1.5), 7.63 (1H, d, J=8.4); ¹³ C NMR (CD₃ OD) δ 194.2, 146.0, 143.0, 139.8, 133.6, 124.9, 120.7, 116.6; Anal. Calcd for C₈ H₆ N₂ O: C, 65.75; H, 4.14; N, 19.17. Found: C, 65.60; H, 4.17; N, 19.08.