Acetoxyacetyl chloride → HCID 20814102, compound

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.

1. customThe mixture was quenched with satd
2. customammonium chloride (50 mL), the layers separated
3. extractionthe aqueous phase extracted with DCM (60 mL)
4. washThe combined organic layers were washed with brine
5. dry with materialdried (MgSO4)
6. concentrationThe residue after concentration
7. dissolutionwas dissolved in acetic acid (50 mL)
8. temperatureheated at 100° C. for 30 min
9. concentrationThe solution was concentrated
10. custompurified by flash chromatography (eluent DCM-ethyl acetate 3:1, 2:1, 1:1)

ORD record

ord-4438e2cc96c045688484efb569c2f4b3

Source dataset

uspto-grants-2005_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06919331B2