Acetoxyacetyl chloride → HCID 20814102, compound

Participants

Reaction Steps

To a mixture of 2,3-diamino-benzoic acid methyl ester (40.8 mmol) and diisopropylethyl amine (8.5 mL, 49.0 mmol) in dichloromethane (80 mL) at −30° C. was added dropwise a solution of acetoxy acetyl chloride (4.8 mL, 44.9 mmol) in DCM (15 mL). The mixture was allowed to warm to room temperature and stirred overnight. The mixture was quenched with satd. ammonium chloride (50 mL), the layers separated and the aqueous phase extracted with DCM (60 mL). The combined organic layers were washed with brine and dried (MgSO4). The residue after concentration was dissolved in acetic acid (50 mL) and heated at 100° C. for 30 min. The solution was concentrated and purified by flash chromatography (eluent DCM-ethyl acetate 3:1, 2:1, 1:1) to give 2-acetoxymethyl-1H-benzoimidazole-4-carboxylic acid methyl ester (7.3 g, 72% yield over 2 steps) as an off-white solid.

Provenance & Evidence