Oxalic Acid → Tert-butyl [2-(aminomethyl)phenyl]acetate oxalate salt

Participants

Reaction Steps

To a solution of 78.0 g (0.312 mol) 2-azidomethylphenylacetic acid t-butyl ester in 1.36 L TBF was added 7.8 g (50% water wet) 5% Pd on C and the mixture shaken mechanically in a 2 L heavy-walled flask under H2 at 45 psi for 2 h. The catalyst was removed by filtration through a bed of celite, rinsing with 250 mL THF. To the filtrate was added a solution of 31.25 g (0.347 mol) oxalic acid in 500 mL methyl tert-butyl ether, and the resultant suspension stirred at room temperature for 30 min. The solid was collected on a filter and washed with 300 mL methyl tert-butyl ether (the filtration was very slow, requiring about 3 hours). Drying under reduced pressure at 60° C. for 18 h gave 42.4 g (39% overall from 2-bromomethylphenylacetic acid) tert-butyl [2-(aminomethyl)phenyl]acetate oxalate salt as a white powder. The product is unstable as the free base, and will cyclize to the amide over several hours at room temperature.

Provenance & Evidence