tert-butyl N-(2-methoxyphenyl)carbamate → 2-Methoxyaniline

Participants

Reaction Steps

0.35 g of tert-butyl-N-(2-methoxyphenyl)carbamate (theoretically 2 mmol/g) bonded on solid support 8 is reacted with 0.5 ml (7 mmol, 10 eq) of a 20% solution of TFA/CH2Cl2 at room temperature for 1 hour. The resin is filtered on a scintered filter and rinsed with CH2Cl2 and MeOH. Then, the filtrate is concentrated under vacuum, taken up in CH2Cl2, washed with a saturated aqueous NaHCO3 solution. After drying on MgSO4 and evaporation of the solvent, 31.1 mg of 2-methoxyaniline is obtained and characterized by the 1H NMR spectrum and compared with the commercial product (yield: 36%). An IR control of the resin showed that the cleavage was not complete (presence of a carbonyl band at 1729 cm−1). The resin was then reacted again with 10 equivalents of a 20% solution of TFA/CH2Cl2 for 15 hours at room temperature. After an identical treatment, 13.8 g of pure 2-methoxyaniline were obtained (overall yield: 52%).

Provenance & Evidence