تفاعل #9062

معادلة التفاعل

(2-nitrophenyl)-terephthalamic acid methyl ester

acetic acid

→

methyl 4-(benzimidazol-2-yl)-benzoate

المردود 86.0%

ظروف التفاعل

المعالجة

1. 1
   درجة الحرارةat reflux for 1 h
2. 2
   درجة الحرارةThe mixture was cooled
3. 3
   workup.STIRRINGstirred at room temperature for 2 h
4. 4
   تركيزconcentrated under reduced pressure
5. 5
   أخرىThe residue was partitioned between saturated sodium bicarbonate (10 mL) and ethyl acetate (10 mL)
6. 6
   أخرىthe phases separated
7. 7
   غسيلthe organic layer washed with saturated NaHCO3 (10 mL)
8. 8
   استخلاصThe organic extract
9. 9
   تجفيفwas dried (MgSO4)
10. 10
    ترشيحfiltered
11. 11
    تركيزconcentrated

الإجراء التجريبي

To a solution of (2-nitrophenyl)-terephthalamic acid methyl ester (0.23 g, 0.76 mmol) in glacial acetic acid (2.5 mL) was added iron powder (<5 μm mesh, 0.12 g, 2.1 mmol) and the mixture stirred at reflux for 1 h. The mixture was cooled, stirred at room temperature for 2 h and concentrated under reduced pressure. The residue was partitioned between saturated sodium bicarbonate (10 mL) and ethyl acetate (10 mL), the phases separated and the organic layer washed with saturated NaHCO3 (10 mL). The organic extract was dried (MgSO4), filtered and concentrated to give cyclized methyl 4-(benzimidazol-2-yl)-benzoate (0.163 g, 86%). 1H NMR (CDCl3) δ 3.96 (s, 3H), 7.32 (m, 2H), 7.53 (br, 1H), 7.84 (br, 1H), 8.17 (m, 4H), 9.65 (br, 1H (NH)).

المصدر