4-Carboxy-3-fluorobenzeneboronic acid pinacol ester → 2-Fluoro-4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-phenyl[2-(S)-(2-(R)-methyl-pyrrolidin-1-ylmethyl)-pyrrolidin-1-yl]-methanone

Participants

Reaction Steps

A 100 mL toluene/EtOH mixture of commercially available 4-carboxy-3-phenyl boronic acid and pinacol is stirred at 75-80° C. for 2 hours, then concentrated, slurried in toluene, concentrated, and dried in vacuo to give 2-Fluoro-4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-benzoic acid that is used without further purification. The title intermediate is prepared in a manner substantially analogous. General Procedure E using 2-(R)-methyl-1-(2-(S)-pyrrolidinylmethyl)pyrrolidine and 2-Fluoro-4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-benzoic acid. The crude product is confirmed by NMR and MS (MS+) 417.5 (M+H)+ then used without further purification.

Provenance & Evidence