Pyridine → 2-(2'-tert-Butylsulfamoyl-3-fluoro-biphenyl-4-ylcarbamoyl)-pyrrolidine-1-carboxylic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

Pyrrolidine-1,2-dicarboxylic acid 1-tert-butyl ester (1.6 g, 7.4 mmol) was dissolved in 40 mL dry diethyl ether under Ar, cooled in an ice water bath, added dry pyridine (3 mL, 37.2 mmol) followed by the dropwise addition of oxalyl chloride (1.6 mL, 18.6 mmol). A precipitate forms immediately. The reaction was stirred vigorously at 0° C. for one hour, then at ambient temperature for one hour. Added 50 mL diethyl ether, filtered off solids washing with diethyl ether. Concentrated the filtrates to an off-white oil. Redissolved oil in 40 mL dry DCM under Ar, cooled to 0° C., added 3 mL pyridine followed by 4′-amino-3′-fluoro-biphenyl-2-sulfonic acid tert-butylamide (2 g, 6.2 mmol). The reaction was allowed to warm to ambient temperature, stirred for 3 hours then concentrated. Redissolved in 250 mL EtOAc, washed with 10% citric acid (2×100 mL), water (3×100 mL), brine (100 mL), dried with MgSO4, filtered and concentrated. Purified on a silica gel column eluted with 30% moving to 50% EtOAc in hexanes. Combined and concentrated pure fractions to yield title compound as a white solid. (1.4 g, 42%) APCI (AP−): 518.2 (M−H)−.

Provenance & Evidence