18-Crown-6 → 3-(2-Fluoro-6-nitrophenylamino)propionic acid methyl ester

Participants

Reaction Steps

To a solution of 1,2-difluoro-3-nitrobenzene from Example B1 (500 mg, 3.1 mmol) in acetonitrile (25 ml) were added β-alanine methyl ester hydrochloride (440 mg, 3.1 mmol), potassium fluoride (310 mg, 5.3 mmol), 18-crown-6 (84 mg, 0.3 mmol) and diisopropylethylamine (1.2 ml, 7 mmol). The mixture was stirred at reflux for 2 h, cooled and evaporated in vacuo. The residue was partitioned between water and EtOAc. The organic layer was washed with brine, filtered and evaporated in vacuo. The residue was purified by flash chromatography on silica (eluant EtOAc:pet. ether 25:75); yield 650 mg, 86%.

Provenance & Evidence