O-Phenylenediamine → 2-[(4-chlorophenoxy)methyl]-1H-1,3-benzodiazole

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Reaction Steps

A suspension of phenylene diamine (10.8 g, 0.1 mol) and 4-chlorophenoxyacetic acid (18.66 g, 0.1 mol) in 4M HCl (150 mL) was refluxed overnight under Ar. The reaction mixture was then cooled in an ice bath. The solid was collected and washed with H2O (150 mL). To the solid was added MeOH (100 mL), CH2Cl2 (400 mL) and 20% aqueous NaOH (300 mL). After stirring for 30 min, the organic phase was separated, filtered through phase separation filter paper, and concentrated in vacuo to give a solid. This solid was triturated with hexanes (150 mL), collected, washed with hexanes (100 mL), and dried to give 17.5 g (68%) of 52 as a pink solid. The HPLC analysis showed a purity of 100%. 1H NMR (60 MHz, d6-DMSO): δ 11.5 (br s, 1H), 6.9-7.5 (m, 8H), 5.3 (s, 2H).

Provenance & Evidence