Water → 1H-Benzimidazole-4-carbohydrazide

Participants

Reaction Steps

Benzimidazole ester 3 (1.65 g, 9.36 mmol), hydrazine monohydrate (10 mL), and water (3 mL) were refluxed in EtOH (60 mL) for 24 hs. Reaction mixture was cooled to room temperature and solid formed was filtered, washed with EtOH and dried to give 1.13 g (68%) of pure 4: 1H NMR (DMSO-d6) δ 12.31 (br.s, 1H), 10.59 (s, 1H), 8.44 (s, 1H), 7.86 (d, 1H, J=6.5 Hz), 7.76 (d, 1H, J8.0 Hz), 7.34 (t, 1H, J=8.0 Hz), 4.68 (s, 1H).

Provenance & Evidence