Pyridine → HCID 68805934, compound

Participants

Reaction Conditions

Reaction Steps

Pyrrolidine-1,2-dicarboxylic acid 1-tert-butyl ester (3.8 g, 18 mmol) was dissolved in 150 mL dry diethyl ether under Ar, and the resulting solution was cooled in an ice water bath, while dry pyridine (8.6 mL, 106 mmol) was added, followed by the dropwise addition of oxalyl chloride (4.6 mL, 53 mmol). A precipitate formed immediately. The reaction was stirred vigorously at 0° C. for one hour, then at ambient temperature for one hour. 100 mL of diethyl ether were then added, and the solids were removed by filtration washing with diethyl ether. Concentrated the filtrates to an off-white oil. Redissolved oil in 50 mL dry DCM under Ar, cooled to 0° C., added 6 mL pyridine followed by 4-bromo-2-fluoroaniline (3.4 g, 17.7 mmol). The reaction was allowed to warm to ambient temperature, stirred for 3 hours then concentrated. Redissolved in 250 mL EtOAc, washed with 10% HCl (3×100 mL), brine (100 mL), dried with MgSO4, filtered and concentrated. Purified on a silica gel column eluted with 20% moving to 40% EtOAc in hexanes. Combined and concentrated pure fractions to yield title compound as a white solid. (3.2 g, 47%) APCI (AP−): 385.1, 387.1 (M−H)−.

Provenance & Evidence