Ammonia → HCID 178423969, compound

Participants

Reaction Steps

2-Hydroxy-4-methylbenzimidazole (5.92 g, 40 mmol) and 40 ml of phosphoryl chloride are introduced into a 250 ml two-necked flask under an argon atmosphere, equipped with a magnetic stirrer. The mixture is refluxed for 20 hours and the phosphoryl chloride is evaporated off under vacuum. The solid obtained is taken up in water (250 ml), the mixture is neutralized to pH=8 with 28% aqueous ammonia and the aqueous phase is extracted with ethyl acetate (3×250 ml). After the usual work-up, the 2-chloro-4-methylbenzimidazole is obtained in a yield of 93% (6.23 g). 1H NMR (300 MHz, δ ppm) DMSO-d6: 2.47 (s, 3H), 7.01 (d, 1H), 7.11 (t, 1H), 7.32 (d, 1H).

Provenance & Evidence