O-Phenylenediamine → 2-[(3-methoxyphenoxy)methyl]-1H-benzimidazole

Participants

Reaction Steps

A suspension of phenylenediamine (15.12 g, 0.14 mol) and 3-methoxyphenoxyacetic acid (25.5 g, 0.14 mol) in 4M HCl (150 mL) was refluxed overnight under Ar. The reaction mixture was cooled in an ice bath. The solid was collected and washed with cold H2O (200 mL). To the solid was added CH2Cl2 (150 mL) and saturated NaHCO3 (150 mL). After stirring for 1 hr, the organic phase was separated, washed with brine (75 mL), filtered through phase separation filter paper and concentrated in vacuo to give 32.7 g (92%) of 51 as an oil which solidified. The HPLC analysis showed a purity of 98%. 1H NMR (60 MHz, CDCl3): δ 10.0 (br s, 1H), 6.3-7.9 (m, 8H), 5.0 (s, 2H), 3.7 (s, 3H) ppm.

Provenance & Evidence